Underfloor Heating Repair: Troubleshooting and Fixing Radiant Floor Issues

Radiant underfloor heating systems offer some of the most efficient and comfortable heating available—but like any mechanical system, they can occasionally need attention. Whether you’re dealing with uneven heating, system pressure loss, or a full zone that won’t warm up, understanding the basics of underfloor heating repair can help you avoid costly service calls and restore comfort faster.

This guide focuses on hydronic (water-based) systems, covering common issues, how to troubleshoot them, and when it makes sense to repair versus replace. Visual diagrams and tips are included to help homeowners, contractors, and builders identify and fix problems quickly.

How Hydronic Underfloor Heating Systems Work

Hydronic radiant systems heat your space by circulating warm water through a network of tubes embedded in or below the floor. The heat radiates up, warming floors and the air above evenly.

System Components:

  • PEX tubing laid in loops beneath flooring
  • Manifold system with valves and actuators
  • Pump and heat source (e.g., boiler or heat pump)
  • Thermostats and zoning controls

Common Underfloor Heating Problems

Even well-installed systems can experience wear, installation errors, or mechanical failures over time. Here are the most frequent issues and how to troubleshoot them.

1. Uneven Heat or Cold Spots

Causes:
  • Air pockets in the tubing
  • Kinked or damaged PEX
  • Poor loop balancing
  • Sensor or thermostat issues
Fixes:
  • Bleed air from system via the manifold
  • Use an infrared camera or a heat gun to locate cold zones
  • Check and adjust flow rates at the manifold
  • Inspect and recalibrate zone thermostats

2. Zone Not Heating at All

Causes:
  • Actuator or zone valve failure
  • Pump not engaging
  • Thermostat disconnected or faulty
Fixes:
  • Test power to the thermostat
  • Manually open zone valves to test flow
  • Check pump function and verify it’s receiving power

3. System Pressure Drop

Causes:
  • Leaks in fittings, joints, or tubing
  • Expansion tank failure
  • Air in system causing false readings
Fixes:
  • Isolate loops one at a time to identify the leak
  • Inspect visible fittings and test pressure over 24–48 hours
  • Check expansion tank pressure (typically 12–15 psi)

4. Slow Heat-Up Time

Causes:
  • Lack of insulation under slab
  • High-R flooring material (e.g., carpet)
  • Loop design with excessive length
Fixes:
  • Use programmable thermostats to preheat zones
  • Add insulation where possible (especially in basements)
  • Consider supplemental insulation or upgraded panels in future retrofits

Can Tubing Be Repaired?

Yes—if the tubing has been mechanically damaged (from drilling, renovations, or excessive subfloor movement), a repair can be made.

How to Repair PEX Tubing:

  1. Turn off the zone and depressurize the system
  2. Cut out the damaged section
  3. Use PEX couplings and crimp rings to install a new piece
  4. Pressure test before re-covering

When Should You Replace a Panel?

In systems that use modular radiant panels (such as grooved wood or insulated foam boards), it’s often possible to replace just the affected area.

For example:

  • Panel with warped surface
  • Crushed aluminum layer
  • Panels that delaminated due to moisture exposure

A major advantage of modular systems is that flooring can be removed in one area, the panel replaced, and tubing reinstalled without affecting the entire floor.

Example Product Reference:
Panels like Radiantboard and Thermalboard from Warm Brothers Inc. are modular, grooved radiant solutions that allow for isolated repairs. Their layered design supports tubing replacement or repair without tearing up the entire floor.

Preventative Maintenance Tips

The best way to avoid costly underfloor heating repair is through proper design and preventative care:

1. Use Oxygen-Barrier PEX

Prevents corrosion in metal parts of the system.

2. Avoid Overly Long Loops

Stick to 250 ft max to ensure good flow and heat distribution.

3. Install Expansion Joints

In concrete applications, this prevents floor cracks from damaging tubing.

4. Pressure-Test Before Covering

Always perform a pressure test after tubing installation and before pouring or laying finish floors.

When to Call a Professional

You can handle many of the above checks and fixes on your own, especially if you have your system’s layout plan. But call a radiant heating professional if:

  • You’re losing pressure and can’t find the source
  • More than one zone fails at once
  • You need to open flooring or concrete to access tubing
  • Manifold valves, sensors, or controls need advanced diagnostics

Pro Tip:
If your system was professionally installed, you should have a loop map or CAD layout showing all tubing runs, loop lengths, and connections. Always refer to this first.

How WBI Supports Repair-Friendly Installations

While this post is primarily informational, it’s worth noting that Warm Brothers Inc. designs their radiant systems for long-term access and serviceability.

WBI Panel Benefits for Repair Access:

  • Modular board format allows for localized replacement
  • Grooved channels for easy tubing access and reinstallation
  • Aluminum-clad surface offers superior heat transfer and durability
  • Ideal for slab or basement installations where access may be limited

These features help reduce repair time and complexity—especially in long-term residential or light commercial projects. Learn more at wbiwarm.com.

Summary: Underfloor Heating Repairs Are Manageable with the Right Knowledge

Most issues with radiant systems, especially hydronic ones, can be resolved with a few basic troubleshooting steps. Whether you’re addressing uneven heat, cold zones, pressure loss, or tubing damage, having the right tools, layout info, and understanding of how your system works is key.

If your system uses modular panels and high-quality materials, the repair process is even more manageable.

 

Electric Radiant Floor Heating: A Good Choice for Small Spaces

Electric radiant floor heating, a great solution for small spaces like bathroom kitchen etc

Radiant floor heating has become one of the most desirable home upgrades in recent years—offering silent, energy-efficient comfort that starts from the ground up. Among the available options, electric radiant floor heating stands out as a relatively affordable, low-profile solution for small areas like bathrooms..

But how do you know if it’s the right system for your project? And how does it compare to hydronic heating?

In this post, we’ll explore how electric radiant heating works, its pros and cons, where it makes the most sense, and when you might want to consider switching to a hydronic system for larger applications.

What Is Electric Radiant Floor Heating?

Electric radiant floor heating uses heating cables or mats installed beneath your flooring to provide gentle, radiant warmth. When powered, the system generates heat that radiates upward through the floor, warming your feet and the surrounding space.

Common Types of Electric Radiant Systems:

  1. Cable Systems – Flexible heating wires laid in custom patterns
  2. Heating Mats – Pre-arranged cables on mesh, designed for faster installs
  3. Foil-Based Systems – Used under floating floors like laminate or vinyl

These systems are typically connected to a thermostat and may include timers or sensors to improve energy efficiency.

Where Electric Radiant Heating Makes the Most Sense

Electric systems are ideal for:

  • Small bathrooms
  • Powder rooms
  • Small Kitchens
  • Mudrooms or laundry rooms
  • Spot-heating cold floors in entryways or sunrooms

If your goal is to make a single space more comfortable without overhauling your home’s mechanical system, electric radiant is often the easiest and fastest solution.

Advantages of Electric Radiant Floor Heating

a. Easy to Install

Electric systems are thin and often come in mats that roll out directly over the subfloor. Many are DIY-friendly and don’t require major structural changes.

b. No Boilers or Piping

Since they run on electricity, there’s no need for pumps, tubing, or a dedicated mechanical system.

c. Fast Warm-Up Times

Electric coils heat up quickly—usually within 20–30 minutes—making them perfect for on-demand comfort in bathrooms and other small spaces.

d. Zoned Heating Control

Each system can be controlled independently, allowing you to heat only the rooms you use, when you use them.

Limitations to Consider

While electric radiant heating has many benefits, it’s important to understand where it doesn’t shine—especially when compared to hydronic systems.

a. Higher Operating Costs

Electric radiant floor heating operating cost

Electricity is often more expensive per BTU than natural gas, propane, or other fuels. In large areas or continuous use, this can result in high energy bills.

b. Not Ideal for Whole-Home Heating

Installing electric radiant throughout an entire house would be cost-prohibitive to run and manage. It’s best for single-room comfort zones.

c. Difficult Repairs

If the wire or mat is damaged during installation or later renovations, repairs may require pulling up tile or flooring.

Ideal Flooring Types for Electric Radiant Systems

Electric radiant works best with:

  • Tile and Stone – Excellent heat conductors, perfect for bathrooms and kitchens
  • Luxury Vinyl Plank (LVP) – Only if rated for radiant compatibility
  • Laminate – With proper underlayment and foil-based heating

Avoid:

  • Thick carpet or rugs
  • Floating floors with foam backing (unless rated for radiant use)

Always check the flooring manufacturer’s guidelines to ensure compatibility.

How Installation Works

A typical electric radiant installation involves:

1. Planning the Layout

  • Map the space, avoiding permanent fixtures (toilets, cabinets, etc.)

2. Installing Heating Mats or Cables

  • Roll out the mat or lay cables using clips or tape
  • Ensure consistent spacing for even heating

3. Connecting the System

  • Wire to a dedicated thermostat with GFCI protection
  • Some systems include sensors for automatic control based on temperature or moisture

4. Applying Mortar and Flooring

  • Cover with self-leveling compound or thinset
  • Install tile, LVP, or other finished flooring

Installation can often be completed in a day or two, depending on the size and complexity of the room.

What About Hydronic Radiant Floor Heating?

Hydronic Radiant Floor Heating for small spaces

While electric radiant heating is great for small spaces, hydronic radiant systems—which circulate warm water through PEX tubing beneath the floor, are a better fit for whole-home applications or large zones.

Why Consider Hydronic Systems for Larger Spaces?

  • Lower long-term operating costs
  • More energy-efficient in large square footage
  • Ideal for new construction or major remodels
  • Compatible with multiple heat sources (boilers, heat pumps, solar)

Hydronic systems also offer broader design flexibility and are better suited for areas over concrete slabs or basement floors—especially when paired with insulated radiant panels.

Warm Brothers Inc. offers engineered radiant solutions like Thermalboard and Radiantboard—ideal for hydronic heating in large areas or entire homes. These panels integrate radiant tubing grooves and built-in EPS insulation to maximize performance while simplifying installation.

Energy Efficiency Tips for Electric Radiant Floors

If you’re using electric radiant heating, here’s how to get the most out of it:

a. Use a programmable thermostat to limit operating times
b. Preheat the space before showers or morning routines
c. Add area rugs only in non-heated zones
d. Insulate below the system if installing over a crawlspace or slab

By using it strategically, you can enjoy the comfort of electric radiant heat without a major impact on your utility bills.

Cost Expectations

Electric radiant heating is typically affordable to install, but more costly to operate long term.

Factor Electric Radiant
Material Cost $8–$15/sq ft
Installation Cost $5–$10/sq ft
Operating Cost Higher (based on kWh)
Best Use Case Small spaces and spot heating

Final Thoughts: When Electric Radiant Heating Makes Sense

Electric radiant floor heating, a great solution for small spaces

Electric radiant floor heating is a great solution for small spaces where comfort, speed, and simplicity matter most. Bathrooms, kitchens, and laundry rooms are perfect candidates for this kind of system. The warm floors make a noticeable difference, especially on chilly mornings.

However, if you’re looking to heat your entire home, or even several large rooms, you may be better served by a hydronic radiant system—which offers lower operating costs, flexible fuel sources, and long-term energy savings.

Need Help Planning a Radiant Heating Project?

If you’re ready to explore options beyond electric systems—especially for full homes or large zones—consider looking into hydronic panel systems like those offered by Warm Brothers Inc. These include:

  • Thermalboard – A low-profile solution for slab floors
  • Radiantboard – Designed for high-efficiency homes and whole-home comfort

For more information, visit wbiwarm.com or connect with a radiant heating professional.

 

The Many Radiant Panels Offered By Warm Brothers Inc.

ABOUT THE MANY RADIANT PANELS OFFERED BY WARM BROTHERS INC.

The Rationale Behind a Diverse Product Line

WBI’s commitment to providing comprehensive radiant heating solutions is evident in its diverse product lineup. The company’s product range is designed to address the varying needs of different construction projects, including new builds, remodels, and retrofits. By offering multiple panel options, WBI ensures that contractors and homeowners have access to the most suitable products for their specific requirements.

The diversity in WBI’s product line allows for flexibility in design and installation. Whether dealing with insulated or uninsulated subfloors, concrete slabs, or even walls and ceilings, WBI has a panel solution tailored to each scenario. This versatility not only simplifies the selection process but also enhances the overall efficiency and effectiveness of the heating system. All products made in USA using materials produced in the USA.

Ecowarm® RadiantBoard™

Ecowarm® RadiantBoard™ is a premium radiant floor heating panel designed for over-subfloor installations. Constructed with a high-quality plywood substrate and laminated with highly conductive aluminum. Grooved channels hold ½” PEX tubing, making it ideal for luxury custom homes and high-performance buildings.

Over Insulated Subfloor

Advantages:

  • Superior thermal conductivity for efficient heating.
  • Appropriate for use with set-back thermostats.
  • Typically comfortable at lower set point than forced air heat.
  • Quick response time and reduced energy consumption.
  • Compatibility with almost all flooring types, including hardwood and tile.
  • Even quiet comfortable heat.
  • Enhanced durability and longevity.

Installation: Ecowarm® RadiantBoard™ is installed directly over the subfloor, with the PEX tubing laid into the panel’s grooves. The modular design simplifies the installation process, allowing for precise and consistent tubing layouts.

ThermalBoard™

ThermalBoard™ is a cost-effective, low-profile radiant floor heating panel suitable for over-subfloor installations. Made from 92% pre-consumer recycled content, it aligns with sustainable building practices. The panel’s aluminum laminate ensures efficient heat transfer, while its lightweight design facilitates easy handling and installation.

Advantages:

  • Environmentally friendly with high recycled content.
  • Meets many LEEDS requirements
  • Lightweight and easy to install, reducing labor costs.
  • Efficient heat distribution for consistent comfort.
  • Suitable for almost all flooring types including hardwood and tile.
  • Installation: ThermalBoard™ is installed directly over the subfloor, with 3/8” PEX tubing inserted into the panel’s grooves. Its low profile makes it an excellent choice for retrofit projects where maintaining floor height is crucial.

Ecowarm® RadiantBoard EPS™

Ecowarm® RadiantBoard EPS™ is an enhanced version of the standard Ecowarm® RadiantBoard™, featuring an integrated layer of expanded polystyrene (EPS) foam insulation bonded to the bottom of the board. This addition improves thermal efficiency by reducing heat loss to the subfloor and enhances sound dampening properties.

Ecowarm® Radiantboard EPS™ over Concrete Slab

Ecowarm® Radiantboard EPS™ over Wood Subfloor

Advantages:

  • Very useful over unheated slabs to reduce downward heat loss.
  • May also be used over under-insulated subfloors
  • Integrated EPS foam insulation for improved energy efficiency.
  • Enhanced sound dampening properties.
  • Water and mold-resistant EPS foam.
  • Available in R-2.7 and R-5.6 values; custom R-values available.

Installation: Ecowarm® RadiantBoard EPS™ can be installed over insulated or under-insulated subfloors, concrete slabs, and even walls and ceilings. The panels are secured using adhesive and/or mechanical fasteners, and PEX tubing is laid into the grooves for optimal heat distribution. The integrated insulation layer eliminates the need for double plating, simplifying the installation process. Ecowarm® RadiantBoard EPS™

Ecowarm EPS™ over Un-Insulated Slab

ThermalBoard EPS™

ThermalBoard EPS™ combines the features of the standard ThermalBoard™ with an added layer of expanded polystyrene (EPS) foam insulation. This integration enhances thermal efficiency by directing heat upward into the living space, reducing heat loss to the subfloor.

Thermalboard EPS™ over Un-Insulated Subfloor

Advantages:

  • Improved insulation properties for enhanced energy efficiency.
  • Moisture-resistant EPS foam helps in preventing mold and mildew growth.
  • Suitable for over-concrete slab installations, basements, and garages and work buildings .
  • Lightweight and easy to handle.

Installation: ThermalBoard EPS™ is installed over concrete slabs, with the EPS foam side facing down. The panel is secured using adhesive and/or mechanical fasteners, and PEX tubing is laid into the grooves for optimal heat distribution.

InsulHeat™ Underslab

InsulHeat™ is designed for under-concrete slab installations, providing both the place for radiant heating tubing and being the insulation in a single panel. The panel’s rigid construction supports the weight of the concrete while minimizing heat loss through the slab.

Insulheat™ EPS Underslab Foam

(in Stock Now)
Blog Image5

 

Advantages:

  • Combines radiant heating and insulation in one panel.
  • High compressive strength supports concrete weight.
  • Moisture-resistant properties prevent damage over time.
  • Ideal for new construction projects.

Installation:
InsulHeat™ panels are placed directly on the well compacted subgrade before pouring the concrete slab. The PEX tubing is then laid into the panel’s grooves, and the slab is poured over the panels, embedding the tubing for efficient heat transfer. Placement of steel mesh is easily accommodated.

Advantages of The WBI’s Radiant Floor Heating Panel Products

  • WBI’s radiant floor heating panels are all designed to exemplify the WBI Value Proposition to bring to the customer the optimal mix of performance cost and environmental responsibility.
  • All the different panel types needed for a project can be ordered and delivered together direct from one supplier.
  • All the required panels can be laid out by the expert WBI design service simplifying the construction process.

Detailed layout plans

Hoyt Corbett

ABOUT THE AUTHOR

Hoyt Corbett

Partner, Warm Brothers Inc.

Hoyt has been involved with hydronic heating since the early 1990’s and developed and sold a national brand of radiant floor heating that was acquired by Uponor. Subsequently, Hoyt was Associate Director of the Radiant Panel Association, the industry trade group.

He’s produced extensive technical writing on radiant floor heating, writing several major national hydronic vendor’s radiant heating design and installation manuals as well as founding and publishing The Radiant Flooring Guide.

RADIANT FLOOR HEAT AND THERMOGRAPHY

A Geeks Guide To The Radiant Electromagnetic Spectrum

While radiant heat can be felt when you are on a radiantly heated floor, it usually can not be heard and can not be seen. This makes it hard to visualize what it really is. In physical terms what is radiant heat? Wonderfully, thermographic cameras help us “see” what “radiant heat” looks like. While thermographic images are a representation of what can not be seen, they look warm an understandable.

Radiant Heat lies just outside of the visible light we see in the Infrared band

For those of you who do not know, Thermography is the use of thermograms to study heat distribution in structures or regions, for example in detecting tumors or in our case understanding radiant floor heating. The wonderful thing about Thermographic cameras is they give us images and readings of the Infrared part of the electromagnetic spectrum, almost all of which is just beyond our range of seeing visual light. So, in a sense these cameras extend our senses and understanding of radiant heating.

Infrared Radiant Floor Heating

Whether it is hydronic warm water radiant floor heating or electric radiant floor heating, a  radiant floor heating system emits almost all of its electromagnetic energy as infrared (IR) radiation, specifically in the long-wavelength IR range (around 8–15 microns). Very little to no energy is emitted in other electromagnetic frequencies that aren’t picked up by an infrared camera — especially if the camera is designed for building diagnostics (which usually covers the key thermal IR spectrum). So, you’re already “seeing” a visualrepresentation of the vast majority of radiated energy. 

Infrared cameras come in many shapes and sizes These are from FLIR.

Radiant heat energy is transmitted at a frequency of the electromagnetic spectrum that we can’t see but can feel and usually cant hear makes for its hidden silent comfort. But by using an infrared camera we are seeing a good visulization of the radiant energy we can’t see. They also have many uses for the contractor.

Courtesy of Infrared Thermal Imaging Services (above 3 images)

This image was used to find a leak but thermography can help find where you can drill in a radiant floor. They are also usefull in analyzing leaky and under insulated areas in a thermal envelop of a home. 

Courtesy of Infrared Thermal Imaging Services

 I have A FLIR Thermal Imaging Camara which I use to compare radiant heating prototype products. This camera, when set correctly and verified by temperature sensing thermistors is a very useful tool. FLIR and other brands have proprietary software where you can import thermal images and edit them. The most usefull tool in this software allows you to make a rectangle of an area and it will compute the high, low and average temperature of the rectangle. If that area is a correctly chosen area of a radiant floor heating board product it can be very useful in initial product protype selections and comparisons.

The above image shows a box I drew using FLIR Ignite sofware. The box contains a cross section of 2 runs of radiant tubing in a radiant floor system covered by 1/4″ of Hardy Backerboard and 3/4″ of wood. The box has been formatted to show the high low and computed average surface temperature in the box. The left tube is next to a colder outside wall.  In this case the high was 85.6 °F, the low 80 °F and the computed average surface temperature was 83.6 °F.

This can become even more  useful when compared to the radiant heating  Nomograph found in the ASHRAE Handbook when you know the water temperature and R-Value of the flooring goods and AUST (Average Unheated Surface Temperature).

The first section of this blog shows some examples thermal images that map  radiant floor heating systems using a thermal imaging camera. For Many of you this first section may be the bulk of what you find interesting. The Part 2 that follows is a geeky dialog I had with CHAT GPT about thermograpy and radiant floors. I have only slightly edited it:

Q: Is much radiant energy outside the Infrared?:

A hot water radiant floor heating system emits almost all of its electromagnetic energy (heat as infrared (IR) radiation, specifically in the long-wavelength IR range (around 8–15 microns). Very little to no energy is emitted in other electromagnetic frequencies that aren’t picked up by an infrared camera — especially if the camera is designed for building diagnostics (which usually covers the key thermal IR spectrum). So, you’re already seeing the vast majority of radiated energy.

Most building-grade IR cameras (like FLIR or Testo models) detect radiation in the 8–14 micron range. This is perfect for detecting radiant floor heating systems. You’re essentially capturing nearly all radiated thermal energy aimed at its field of view.

The radiated energy spectrum comes from the top surface’s temperature and emissivity, not from the heat source (e.g., not directly from the water pipes) underneath.

 Q: What do the floor coverings affect?:

  1. Emissivity (How Well the Surface Radiates)
  • Different materials have different emissivities (effectiveness in emitting IR radiation).
  • High-emissivity materials (like matte tile or wood): Radiate well; your IR camera sees accurate thermal patterns.
  • Low-emissivity materials (like polished stone, aluminum foil): Reflect IR and can mislead your camera — you might be seeing reflections instead of true temperature readings.

 

some portion of the IR energy is scattered/emitted in directions other than toward the camera, but this is not energy the camera is “missing” in error — it’s just not in its field of view, it is just expected behavior based on physics.

The percentage of total emitted radiant energy that doesn’t go toward the camera depends on your viewing angle and coverage, but under typical conditions, it is far more than 10% — closer to 80–90% of the energy radiates in other directions.

Let me explain:

 Q: Why So Much Energy Goes Elsewhere?

🔸 1. Radiant Heat is Emitted in All Directions (Hemisphere)

  • A surface radiates over a hemisphere (180°).
  • The FLIR camera sees only a narrow cone (e.g., 25–45° field of view depending on lens).

 

Q: If so much of the radiant energy is being missed, how is the reading relevant or close to the standard radiant floor heating Nomograph contained in the ASHRAE Hanbook? The answer is the camera is quite accurately reading the floor temperature in the area of its view. The AHRAE Nomograph relates Floor Tempertures to Room temperatures with adjustments for AUST (Average Unheated Surface Temperature).

Some portion of the IR energy is scattered/emitted in directions other than toward the camera, but this is not energy the camera is “missing” in error — it’s just not in its field of view. The FLIR camera captures the radiance in the direction it’s pointed, and this is expected behavior based on physics.

The percentage of total emitted radiant energy that doesn’t go toward the camera depends on your viewing angle and coverage, but under typical conditions, it is far more than 10% — closer to 80–90% of the energy radiates in other directions.

Let me explain:

 Why Does So Much Energy Goes Elsewhere?

🔸 1. Radiant Heat is Emitted in All Directions (Hemisphere)

  • A surface radiates over a hemisphere (180°).
  • The FLIR camera sees only a narrow cone (e.g., 25–45° field of view depending on lens).

   2. The hemispherically scattered energy is heating walls and surfaces and contributes to       AUST.

Quick Breakdown:

  • FLIR camera can give you a radiometric average based on infrared emissions.
  • ASHRAE nomograph requires a true average surface temperature of the radiant floor to estimate heat transfer and resulting comfort levels, with corrections based on AUST.

Q: How well do these match up then?

They can correlate well—**but with caveats:

  1. FLIR Average = Emissivity-Weighted Average
    FLIR calculates temperature from infrared radiation, which is affected by:

    • Surface emissivity (wood, tile, carpet vary)
    • Angle of view (cosine losses outside normal incidence)
    • Reflections (from walls, furniture, windows, etc.)
    • To a lessor extent by humidity and ambient temperature
    • You’ve set the correct emissivity in the FLIR,
    • You’re measuring at a perpendicular angle (or correcting for angle),
    • You’ve minimized or corrected for reflected IR,

…the “average” it shows could be biased.

  1. ASHRAE Nomograph Assumes an Area-Averaged, Conductively Driven Surface Temp
    ASHRAE’s nomograph expects an accurate spatial average of the floor surface that represents the actual conductive-coupled radiant emission—not just the IR signature. For example:

    • A cold rug or air leak nearby could skew the FLIR average downwards more than it affects heat emission.

Q: What Are Best Practices for Alignment:

  • 🔧 Emissivity Calibration: Make sure your FLIR emissivity settings match the actual floor material (e.g., wood ≈ 0.9, tile ≈ 0.85–0.95).
  • 📏 Multiple Angles & Stitching: Take FLIR images from multiple locations and stitch or average them to approximate full-area values.
  • 🌡️ Compare with Thermistor Probes: If possible, use spot-sensors or contact thermistors in a few zones to calibrate your FLIR reading.
  • Use Corrected FLIR Average for ASHRAE Input: After adjustment, the FLIR average floor temperature can be reasonably close to the ASHRAE value—typically within ±1–2°C, if the above factors are well-controlled.

CHAT GPT CONCLUSION:

The FLIR-derived average floor temperature can be used in conjunction with the ASHRAE radiant floor nomograph, but it needs to be interpreted with care. Proper emissivity settings, angle of capture, and a sense of how IR scattering affects the reading will help you use it effectively. When those are well managed, your FLIR data becomes a strong proxy for what ASHRAE’s model needs.

 

THE AUTHORS CONCLUSION:

In tests  we have done we added very accurate flow meters, water temperature guages and radiant surface temperature thermistors and mostly found good correlation to the results of the Thermogarphic cameras, but the other equipment is an essential way to check accuracy. 

Hoyt Corbett

ABOUT THE AUTHOR

Hoyt Corbett

Partner, Warm Brothers Inc.

Hoyt has been involved with hydronic heating since the early 1990’s and developed and sold a national brand of radiant floor heating that was acquired by Uponor. Subsequently, Hoyt was Associate Director of the Radiant Panel Association, the industry trade group.

He’s produced extensive technical writing on radiant floor heating, writing several major national hydronic vendor’s radiant heating design and installation manuals as well as founding and publishing The Radiant Flooring Guide.

Heated Driveway Installation: What You Need to Know Before You Start

Heated Driveway Installation

Snow and ice buildup on driveways is more than just a winter inconvenience—it’s a safety hazard, a liability, and a time-consuming chore. Whether you’re tired of constant shoveling or simply want a safer, maintenance-free surface, a heated driveway is an investment that offers comfort, safety, and long-term value.

In this guide, we’ll walk through the different types of heated driveway installation systems, how they work, their pros and cons, and what to expect from the installation process. If you’re considering one for your home or business, this will give you a solid foundation before making a decision.

What Is a Heated Driveway?

A heated driveway is an outdoor surface equipped with a snow-melting system that automatically clears ice and snow using heat generated beneath the surface. These systems come in two main types:

1. Electric Snow-Melt Systems

  • Use cables or heating mats embedded in the driveway
  • Connected to a power source and controlled by a thermostat or snow sensor
  • Best for smaller areas due to high operating costs

2. Hydronic Snow-Melt Systems

  • Use a series of tubes (typically PEX) that circulate warm water
  • Powered by a boiler, water heater, or heat pump
  • More complex to install, but much more cost-efficient over time—especially in large areas

Hydronic systems are ideal for full-size driveways, walkways, and commercial applications, while electric systems are better suited for short runs, steps, or tight spaces.

Key Benefits of Heated Driveways

1. No More Shoveling

Heated Driveway Installation no more shoveling

Skip the early mornings and back pain. Heated driveways activate automatically during snowfall, keeping the surface clear without manual labor.

2. Improved Safety

Melting snow and ice at the source reduces slips and falls, which is especially important for households with children, seniors, or frequent visitors.

3. Cleaner Interiors

No more tracking snow, salt, or sand into the house or garage.

4. Increased Property Value

A radiant driveway adds premium appeal to high-end homes, especially in snowy regions.

5. Long-Term Savings

While the upfront cost is higher, a heated driveway reduces the need for snow-removal services, deicing chemicals, and repairs caused by freeze-thaw cycles.

Things to Consider Before Installing a Heated Driveway

Installing a snow-melt system isn’t just about laying tubing under your driveway. Proper planning is essential. Here are the top factors to keep in mind:

 Driveway Surface Material

Radiant systems can be installed under:

  • Concrete
  • Asphalt
  • Pavers

Each has different installation requirements. Concrete is the most compatible, as tubing or cables can be embedded directly into the pour.

Energy Source

Hydronic systems require a dedicated heat source. Common options include:

  • Gas or electric boilers
  • Water heaters
  • Ground-source or air-source heat pumps

Make sure your mechanical system can handle the additional load.

Insulation Is Essential

InsulHeat

Without insulation below the radiant tubing, a significant portion of heat will escape downward into the soil instead of rising to the surface.

Rigid foam insulation panels are commonly used to reduce this heat loss. A properly insulated system heats up faster and operates more efficiently.

Step-by-Step Heated Driveway Installation Overview

The exact process will vary based on your surface type and system, but most hydronic heated driveway installations follow these general steps:

1. Excavation and Site Prep

Excavation and Site Prep for Heated Driveway Installation

  • Remove the existing driveway surface
  • Excavate to the required depth for gravel, insulation, tubing, and slab
  • Install and compact a gravel base for drainage and stability

2. Install Insulation Panels

Install Insulation Panels in Driveways

A rigid foam insulation layer is placed over the compacted base to prevent downward heat loss.

Note: Products like InsulHeat™ by Warm Brothers Inc. are pre-grooved EPS panels that also hold radiant tubing in place—speeding up installation and improving efficiency.

3. Lay Tubing or Cables

  • Hydronic: Run PEX tubing in loops across the surface
  • Electric: Install heating mats or cables as per layout

The tubing is typically attached to rebar or mesh, or placed within pre-cut grooves in insulation panels.

4. Pour Concrete or Lay Pavers

  • For concrete: Pour directly over tubing, ensuring proper depth and coverage
  • For pavers: Use a sand or mortar bed, depending on design

Expansion joints and control cuts should be carefully planned to avoid damaging the radiant system.

5. Connect to Heat Source and Controls

The final step involves connecting the system to a manifold, control sensors, and the heat source. A snow sensor typically automates the system based on temperature and moisture detection.

Average Costs

Heated driveway costs depend on the surface area, system type, and materials used. Here’s a rough breakdown:

Item Cost Range (per sq ft)
Electric System (installed) $12 – $20
Hydronic System (installed) $14 – $25
Insulation Panels $1.50 – $3.00
Heat Source (boiler, pump) $2,000 – $6,000+

While the upfront investment may be significant, especially for larger driveways, operating costs for hydronic systems remain relatively low—especially when integrated with high-efficiency boilers or renewable energy sources.

Maintenance and Longevity

Properly installed heated driveway systems require minimal maintenance. Here’s what to expect:

  • Annual inspection of the manifold, sensors, and mechanical system
  • Pressure testing of hydronic loops if issues arise
  • Snow sensor calibration to ensure efficient operation

With good design and quality components, hydronic systems can last 30+ years, and insulation materials like EPS panels can last the lifetime of the driveway.

Environmentally Smart, Too

Heated driveways don’t have to be wasteful. In fact, they can be more sustainable than traditional methods:

  • No salt or chemical runoff into storm drains
  • No gasoline-powered snow blowers
  • Systems can be paired with solar thermal or geothermal for even greater efficiency

Using proper insulation—like EPS panels—is key to minimizing energy waste.

Final Thoughts: Is a Heated Driveway Right for You?

Heated Driveway Installation

If you live in a cold, snowy climate and want to eliminate manual snow removal, improve safety, and boost curb appeal, a heated driveway is a wise investment. With the right materials and design, these systems provide long-term comfort and energy savings.

Just be sure to:

  • Choose the right type of system for your needs
  • Insist on high-quality insulation to reduce operating costs
  • Work with experienced installers who understand radiant design

One Smart Option: InsulHeat™ Panels

For those exploring hydronic radiant systems, InsulHeat™ by Warm Brothers Inc. is a high-performance EPS insulation panel designed for driveway and outdoor radiant applications. It features:

  • Built-in grooves for PEX tubing
  • Load-bearing EPS construction
  • Simplified layout and installation

It’s a smart choice when paired with any hydronic system where insulation and tubing layout efficiency matter.

Learn More

To learn more about snow-melt design, radiant installation, or to explore engineered products like InsulHeat™, visit wbiwarm.com.

Heated Bathroom Floor Installation: What You Need to Know Before You Start

A heated bathroom floor is more than just a luxury—it’s one of the most sought-after upgrades in modern remodeling. Nothing says comfort like stepping onto warm tile after a shower, especially during the colder months. Whether you’re building a new home or upgrading an existing space, radiant floor heating in a bathroom can dramatically improve comfort and energy efficiency.

In this guide, we’ll walk you through the pros and cons of installing heated floors in bathrooms, how the systems work, what materials are best, and what to consider before getting started.

What Is Radiant Floor Heating?

Radiant floor heating delivers heat from beneath the floor’s surface using either:

  • Electric systems (wire mesh or heating mats)
  • Hydronic systems (warm water circulated through tubing)

The warmth rises evenly from the floor, unlike forced air, which heats the room unevenly and can lose heat through ducts. Radiant systems provide consistent, silent, and energy-efficient comfort—especially under traditionally cold materials like tile and stone.

Should You Install Heated Floors in a Bathroom?

Pros:

  • Instant comfort underfoot
  • Even heat distribution
  • Low noise and no drafts
  • Minimal maintenance
  • Increased home value

Considerations:

  • Higher upfront cost than traditional heating
  • Installation complexity (especially hydronic systems)
  • Floor height increase (depending on the product and layers)

For small bathrooms, electric systems may be more cost-effective due to their simplicity and lower infrastructure requirements. However, if you’re already installing a hydronic radiant system in the rest of the home, including the bathroom in your plan makes both functional and financial sense.

A Realistic Note on Hydronic Heating for Bathrooms

If you’re only heating a standalone bathroom, hydronic radiant systems are not generally recommended. The cost and complexity of installing a manifold, plumbing, and loop system for such a small space usually outweigh the benefits.

However, if the bathroom is part of a larger hydronic radiant floor system, it’s smart to include it. You’ll maintain consistent temperatures throughout the home, avoid having a cold floor in a warm house, and use the same materials and techniques already in place.

Best Floor Coverings for Radiant Heat in Bathrooms

Your choice of flooring will affect the system’s performance. These materials work best with radiant floor heating:

  • Porcelain or Ceramic Tile Top choice due to high thermal conductivity
  • Natural Stone Warms quickly and retains heat well
  • Luxury Vinyl Plank (LVP) Must be labeled for radiant compatibility
  • Engineered Wood Some types are suitable; check specs carefully

Avoid:

  • Thick carpets or rugs with high R-values
  • Floating floors with foam underlayment, unless specifically rated for radiant heat

Installation Overview

Here’s a high-level overview of how a heated bathroom floor installation typically works:

1. Plan Your Layout

  • Measure the area and identify zones
  • Avoid installing heating under cabinets, vanities, or fixtures
  • Account for expansion joints and floor transitions

2. Choose the Right Heating System

  • Electric: Use heating mats or cables with a thermostat
  • Hydronic: Use pre-grooved panel systems if part of a larger system

Electric systems often come in kits and are DIY-friendly. Hydronic systems require more planning but offer better long-term efficiency in larger projects.

3. Install the Subfloor System

If you’re using a hydronic panel system (e.g., Thermalboard or similar), the process may include:

  • Securing panels to a concrete slab or subfloor
  • Pressing PEX or PERT tubing into pre-cut grooves
  • Routing tubing to a central manifold
  • Ensuring tubing is pressure-tested before finishing

For electric systems:

  • Roll out heating mats
  • Connect to the thermostat per manufacturer guidelines
  • Cover with appropriate mortar or self-leveling compound

4. Tile Installation

  • Install a crack-isolation membrane or cement board over the heating system
  • Use polymer-modified thinset for tile installation
  • Allow full cure time before turning on the heat

How Long Does It Take?

For an average bathroom (35–60 sq ft):

  • Electric system: 1–2 days, including floor prep and tile install
  • Hydronic system (as part ofa  larger project): Varies based on access and complexity

Allow at least 7 days for tile and mortar to cure before activating the system.

Cost Considerations

Factor Electric Hydronic (as part of the whole home)
Material Cost $10–$15/sq ft $15–$25/sq ft (installed)
Efficiency Moderate High
Maintenance Low Low
Best For Single rooms Whole-home + bathrooms

A Look at Radiant Panel Options

For those already planning a hydronic radiant system, engineered panel products like Thermalboard and Radiantboard make bathroom integration easier and more efficient.

These systems feature:

  • Pre-grooved aluminum-clad surfaces for PEX tubing
  • Built-in EPS insulation to reduce heat loss into the slab
  • Fast heat-up times and compatibility with tile, stone, or vinyl plank

While Warm Brothers Inc. offers these products to support radiant installations, keep in mind that they are best suited when the bathroom is part of a larger heated floor plan, not as a standalone solution.

Maintenance and Operation

Radiant systems, when properly installed, require very little maintenance. For hydronic systems:

  • Periodically check the manifold and pressure gauges
  • Ensure thermostats are functioning correctly
  • Keep air vents and purge valves clear

Electric systems typically require no service unless a mat is damaged during renovation.

Do Heated Bathroom Floors Increase Energy Bills?

Quite the opposite, if designed correctly.

Radiant heat systems can run at lower temperatures than forced air while maintaining better comfort. Bathrooms often heat faster and retain warmth longer thanks to tile or stone surfaces. With programmable thermostats and zoning, you can limit usage to times when it’s needed most (e.g., mornings and evenings).

Final Thoughts: Is It Worth It?

If you’re already updating your bathroom flooring, installing a radiant heating system—especially electric—can be a relatively simple, high-impact upgrade. It adds resale value, improves daily comfort, and can help reduce reliance on less efficient whole-house systems.

For homes undergoing larger renovations or new builds using hydronic radiant heating, extending coverage to the bathroom makes total sense. Just make sure your heating system is correctly sized and zoned, and that you’re using materials compatible with radiant floor technology.

Learn More

For more advanced radiant floor options using engineered panel systems, including EPS-backed solutions for concrete or basement bathrooms, Visit Us to explore products like Thermalboard and Radiantboard

While these systems may not be the first choice for small, standalone bathrooms, they are incredibly effective when part of a whole-home heating design.

 

IN SEARCH FOR THE IDEAL HYDRONIC RADIANT FLOOR HEATING CONTROL

IN SEARCH OF THE IDEAL CONTROLS FOR HOT WATER RADIANT FLOOR HEATING

There’s nothing like beautifully calibrated hot water radiant floor heat to bring comfort to your spaces or home. In my mind, the ideal control system for hot water radiant floor heating would have the following features: It could be configured and its parameters input, remotely or on site, be enabled to learn its own entire environment and then automatically  adopt the most efficient way to run the system in order to save energy and maximize comfort. With the advent of artificial intelligence this sounds reasonable, but where are we with this?

 

To explain my first requirement, that such a control strategy should be easy to configure both remotely or on site, let me digress into my past experience. In the late 1980s and early 90s I owned and ran a specialty radiant floor heating installation business in the Puget Sound area of Washington state: “Thermal Renaissance”. The idea being that it was a newer and better way to heat homes than forced air, or the older radiant floor heating systems that used copper rather than modern plastic tubing such as PEX.

At Thermal Renaissance, we installed a large number of systems, mostly, but not all, in nice waterfront homes. But as the map of Puget Sound shows, below, getting to those jobs always required driving around waterways and water bodies, taking ferries across the Sound to its many islands, or finding and taking bridges to reach a site. The price of being a specialty contractor was that you took the jobs where you found them. For most of our jobs, 1/3 to 1/2 the labor hours were in travel time.  As you can see from the map below, the coastline is rugged, with many peninsulas and islands:  we did projects or multiple projects on most of them.

During the latter period of my Thermal Renaissance era, Tekmar had the most sophisticated control products, but these were complicated to set up correctly, and we learned to dread the frequent eventuality of an owner deciding to go into the mechanical room and start spinning dials and pushing buttons. This inevitably resulted in another long and inconvenient trip to correctly reconfigure the customer’s controls, often at a time we were busy elsewhere. It even spoiled one Christmas Day for me and my family! Hence, my advice to use controls that can be logged into remotely.

Map of Puget Sound in Washington State

So now, in thinking about an ideal control system, as proposed above, that could learn and perfect the efficiency and performance of the whole system… where are we in the progression to such a possibility? If you look at the below word salad of candidate components of such a control system, you see hints that most of existing system components are already incorporating some adaptive behavior we associate with the promised future power of artificial intelligence.

Components are getting smarter, and some vendors are connecting more of them in increasingly inclusive ways. But so far, we still lack the ability of widely separated components to create a control system that self-learns its own environment and perfects itself in response. But many elements and trends are leading us toward this future. A few examples follow the word cloud below.

 

Word Cloud by Author

Trend 1: Individual Components Getting More Functions

Almost all individual hydronic components are gaining added functions and added “intelligence”. This has gradually been going on for longer than we realize. One of the first ideas was to add adaptive intelligence to set-back capable thermostats. This means that if a hydronic heating system is set back to a lower temperature at nighttime, the adaptive setback thermostat will get better at understanding or “adapting” to the required lag times it takes to set back the heat to the required lower temperature, as well adapting to (getting better at) predicting the lag time required to bring the system back up to daytime temperature.

Today, some thermostats have added “intelligent” features such as the ability to communicate—often wirelessly—with other thermostats and a controller. This allows for new efficiencies in comfort control. For example, the control monitors and finds from the thermostats the highest demand radiant heating zone, adds input from the outdoor temperature and, considering both, runs the system making complex decisions on how to fire the boiler most efficiently.

Today’s smarter pumps, such as Grunfos and Wilo, in particular, have added pumps with many new, easily programmable modes of operation. These “smart pumps” contribute to making the radiant system run more efficiently, and, when programmed correctly, reduce the consumption of electricity: when programmed correctly, they run just sufficiently to meet demand. Here’s the component “word salad” I mentioned above, each word relating to components that are now evolving toward greater functionality.

But again, where are we with my dream hydronic control system where, once all the components are connected, and a very few parameters set, the control then learns its environment and runs itself by means of its programmed intelligence?  For this to happen, each component will truly have to communicate with the central control which needs to be capable of adjusting to each component and with the intelligence to do so. For now, we are still mostly assembling components that, when their collective functions are aggregated, provide excellent overall performance at the expense of complexity and knowing how to assemble and program all the parts.

But here is a product others are busy emulating that comes much closer to a “smart” boiler. For a number of years, most condensing boilers have routinely come with outdoor reset capabilities, but the Alta boiler from US Boiler Products has added 2 newer twists: a “Rate-Based Reset” continually using flame ionization information to adjust the flame.   The Alta’s rate-based temperature reset, means it adjusts its firing rate based on supply and return water temperatures, rather than relying on an outdoor reset sensor.

This (Alta) method assesses environmental conditions, indoors and out, and continually adjusts the boiler’s operation for comfort and efficiency using information it learns from supply and return sensors, as well as from run rate and times. With the addition of advanced flame control the two control features from an installer’s point of view, the Alta has several “Set and Forget” attractions. The installer simply programs the highest water temperature a radiant system might need, the boiler initially ramps up to that temperature, then begins ramping downward until  it is continually equilibrating the water temperature, boiler turn-down and blower speed.

The boiler has a 10-to-1 turn down. The argument for rate-based reset is that it is less likely to be fooled by changes due to wind, variable sunlight exposure, etc. So, while it does meet my hopes for a control that, once set up, learns and adjusts itself, it does not currently allow remote adjustment over the internet. In addition to its onboard rate-based reset, the adaptive flame ionization analysis is  constantly analyzing and adjusting the boiler flame for a clean and efficient flame.  The simplicity and autonomy of this control is its appeal. Since the control itself does so much, it requires way less training than a more complex control. I have a sales rep friend who has over 5000 of these in service and in his words “with almost no problems”. While I said ideally a control should be able to be remotely configured, I would give that up for one that was reliable enough to hardly ever need to be reprogrammed and simple enough to program that it can be explained with a video or over the phone.

Alta Boiler from US Boiler

Tekmar and others now have controls that that can do indoor/outdoor combined resets with thermostats that communicate the highest demand, then the control takes all of this into account. While many allow for remote login, they are still not yet part of the heat source’s brains, BUT instead they are supplanting or extending it.

Trend 2: Controls That be Configured For Multiple Functions

HBX controls exemplify another trend to watch as we march towards more intelligent controls. In order to cost-effectively have fewer SKUs, these new HBX modules can be given many functions, and have good communication functions.

ZON 0600

Trend 3: Already Smart Heat Sources Are Getting Smarter

Air-to-Water Heat Pumps and Geo Thermal Heat Pumps are already  complex machines that, in order to be efficient, usually already have a lot of “programmed intelligence” in order to run the sophisticated controls that continuously monitor and change their operation. In the heating mode in particular, adding another external control that turns them into an on-off controlled appliance reduces efficiency, although smart thermostats and smart secondary loop pumps are a good idea. Running these heat pumps in “Cooling Mode” is another story which involves integrating dehumidification.

Engineer John Williams at Chilltrix has added an intelligently integrated  cooling/humidity control: by controlling humidity and the heat pump operation, it allows the unit to seek, in cooling mode, the highest water temperature that will meet the needs of cooling and dew point protection. The result is extreme high efficiency in the cooling mode, as well as very high annual efficiency as a result. Williams, who previously worked on satellite control and communication systems, said these new controls have more computing horsepower than NASA’s Apollo missions: “So as far as intelligent controls go, you guys haven’t seen anything that compares to what’s next!”  ArcticAir, Raypak and others have new cold weather air to water heat pump models, meaning the geographic market for air to water heat pumps is growing. Their controls have also expanded their functionality.

Chiltrix Air To Water Heat Pump

ArcticAir, Spacepak and others have new high efficiency extreme cold weather air to water heat pumps

Newer Low temperature heat pumps require significant “brain power” to make these Complex machins so efficient.

If you are curious to really know how complex the control of an air to water heat pump are ask Chat GPT to give you “air to water heat pump variable speed compressor control logic model” …you will get about a ten page disscussion in detail of all the many things that are considered and controlled. The top paragraph is very general but then it gives a great deal of detail.

Water Furnace Geothermal Heat Pump and Water Tank

Geothermal heat pumps used for hydronic heating can be similarly advanced. Here is a link to a video about the Water Furnace control system: (note you will initially denied access but if you click the more info box then check you are human in the 2 capcha boxes you will be able to access the video. It will open a new tab.

I conclusion I realize that is not surprising that air to water heat pumps and geo thermal heat pumps pack so much on board adaptive computing power. They are after all be far more energy efficient that traditional boilers and as such ARE the future of hydronics. Their long term future is clear since they are environmntally friendly and save energy. Unfortunately as I send this blog to press, the supply chain for these is in the short term clouded by uncertainty regarding tariffs. Since parts for these heat pumps often come from all over the world, comapanies may realign where they are assembled to then only pay high tariffs on the critical parts that come frome high tariff countries. This may slow but will not stop the exciting evolution of these innovative and needed products.

 

Hoyt Corbett

ABOUT THE AUTHOR

Hoyt Corbett

Partner, Warm Brothers Inc.

Hoyt has been involved with hydronic heating since the early 1990’s and developed and sold a national brand of radiant floor heating that was acquired by Uponor. Subsequently, Hoyt was Associate Director of the Radiant Panel Association, the industry trade group.

He’s produced extensive technical writing on radiant floor heating, writing several major national hydronic vendor’s radiant heating design and installation manuals as well as founding and publishing The Radiant Flooring Guide.

Radiant Heat Installation in Historic Firehouse Renovation with Anthony Carrino

In September of 2019, my partner Morgan Muir and I had the privilege of working with former HGTV celebrity Anthony Carrino (Kitchen Cousins, with his real-life cousin) to do a special radiant heat installation deep dive for Season One of their new show on The Build TV. Anthony’s a fun, knowledgeable production professional—not only as a great construction interviewer, but with expertise in every aspect of filming. He was renovating an old fire station, “The Firehouse” in Jersey City, NJ, to convert to his personal residence. We did two videos with Anthony, each of which I think are incredibly informative about our Ecowarm® RadiantBoard™. You’ll find the links further down in this blog.

Owners Hoyt and Morgan Talk Radiant Heat with Anthony Carrino

Visiting the Historic Firehouse Project

Here we are: (L-R) Morgan, me and Anthony in 2019 at The Hook and Ladder Firehouse #3, built in 1896 in Jersey City, New Jersey. This station served the surrounding neighborhood in Jersey City Heights and remained in service until 2005. In 2015 it was placed on the National Historic Registry. (Wikipedia)

Owners Hoyt and Morgan Talk Radiant Heat with Anthony Carrino
Hook and Ladder #3 in Jersey City, remodel and photo by Anthony Carrino.

The Firehouse renovation was under construction when we first visited to observe and discuss the radiant heat installation of our product, Ecowarm® RadiantBoard™. Later, we filmed. Since then, Anthony has married, now has a daughter, and has moved into the Firehouse full time as the family’s new residence. His dog, seen later in a thermal image, also happily resides here. He was happy with the product, this is what he said.

The product you guys make is incredible. I absolutely loved the install process. What you provide is literally a “paint by number”. This is a level of efficiency that is un-paralled. Not having hot and cold spots when you’re stepping on and off the tubes underneath the floor, having the conductivity spread out across the aluminum, small boards that are easy to carry on a construction site, the ability to cut the boards with a table saw, and having everything pre-drilled — it’s just incredible. Everything ran without a hitch. If you’re in the market for radiant heat, I highly recommend looking into Ecowarm RadiantBoard. Maybe the best part is that they are super nice to work with!

Anthony Carrino Build.tv

Time-Lapse Video and Camera Setup

Click on the above image to view the 8 minute Radiant Heat Installation Video with narration, some overhead fast motion camera sequence of installation or use this link.

Installing Ecowarm Radiant Floor Heating

Before we arrived, Anthony had ingeniously strung overhead wires for a motorized trolley camera he remotely controlled to move it about, capturing footage of the radiant heat installation.

Installing Ecowarm Radiant Floor HeatingScreenshots from video by Anthony Carrino

Installation Process and Techniques

During this radiant heat installation, his crew laid out all the boards according to our layout drawings (a design service we offer all customers), using short pieces of PEX to align each board with the next board, as we recommend. Once the layout was set, the crew picked up each board, applied construction adhesive to the bottom of each board, re-placed them, and screwed them down. Another method of attachment is to use a 3/8” wide sheathing staple and place 2 staple at the specified locations on the boards in opposing directions (forming an X in cross section).

Anthony Carrino Installs Radiant heat

Anthony only half-jokingly complained that the tubing went in so fast, it was hard to make the camera keep up with it. This video shows it all coming together in fast motion, while quickly discussing the radiant heat installation of Ecowarm® RadiantBoard™ in the Firehouse Project. Many people have commented how useful it was in their decision to use our product. The boards for radiant floor heating and radiant tubing were installed (and videoed) while we were there. This area, above, would become the kitchen. Finished kitchen, below.

Radiant heat installation in finished kitchen

Photo by Anthony Carrino

More Photos from the Project: Radiant Heat Installation

Here are some other shots from the project.

Radiant heat installation

Screenshot Anthony and his dog in a thermal image taken after cabinets were installed, showing the effectiveness of the old Fire House’s new radiant heat.

Cozy Living Room with Ecowarm Radiant Floor Heating

Anthony’s finished living room photo by Anthony Carrino

Radiant Floor HeatingOffice photo by Anthony Carrino

Dining Area photo by Anthony CarrinoRadiant Floor Heating with Anthony Carrino

Screenshot Deep Dive Intro

Deep Dive Interview on Radiant Heating

Anthony also did a separate long interview with Morgan and me as part of what he called the Deep Dive series on The Build TV. This video goes into more detail about why our Ecowarm® RadiantBoard™ works so well, and what we were thinking about and taking into consideration as we developed it.

Anthony: “You can check out my Deep Dive interview with them, below, and you can just see how passionate they are about what they do…even after 30+ years each, in the business.”
The video, approximately 36 minutes, is a quick course in who we are, and how and why to use our radiant board product. It covers the following and more:

  • Intro to Warm Brothers partners Morgan and Hoyt, and their combined 70 years in the industry
  • Why the aluminum is on top (for better heat transfer)
  • Light weight and size make it easy to carry upstairs
  • Aluminum is 1200-1500 times more conductive than plywood
  • Radiant comfort and Mean Radiant Temperature explained
  • Cats and a dog moving in together in an outdoor radiant heated doghouse
  • Loops and zones
  • PEX pipe—not Pex-Al-Pex—and why
  • Cutting, screwing or stapling, and routing special channels
  • Why 2 SKUs can do everything

CAPTURED ON CAMERA: WHAT WE LEARNED

The most important thing we learned is that Anthony is a very sincere and knowledgeable interviewer about construction projects. He does a great deal of homework about products in the marketplace, and for example, in the case of radiant floor heating, was very articulate about what people looking into hot water radiant floor heating want to know. He was very experienced on camera from his former experience on HGTV in “Kitchen Cousins”, a show described as follows (with thanks to ChatGPT): “The HGTV show “Kitchen Cousins” focused on both food and construction. While the show featured kitchen renovations, it also included the cousins’ own culinary expertise and their restaurant ventures. They were known for their construction skills, turning mediocre kitchens into masterpieces, but they also had a passion for food, which led them to open an Asian-American restaurant in Jersey City.”

A Fun and Memorable Filming Experience

All Anthony’s experience helped make our visit and filming incredibly fun.

For lunches, for example, Anthony guided us to a wonderful hole-in-the-wall Italian restaurant nearby, where an older woman who spoke English and Italian, gave us a menu, and soon made it clear that, no, she would not cook us or bring us what we were ordering because, “You have not ordered the best things…so I will not make …trust me.” We did, and it was delicious, but totally different from what we’d initially ordered!

The Mark of a Pro: Planning and Precision

The fact that Anthony was able to predict the exact day our product would be installed, a month earlier, so we could get our plane tickets well in advance, made it clear he was a very experienced contractor who knew how to run a project. His earlier TV experience made him very at ease in showing and explaining what is important to potential customers. He is confident in his thoughts and opinions, since he has deep knowledge of products and construction practices, including radiant heat installation. And he was instantly likable! The result is two EcoWarm® videos which are significantly better than anything we could have scripted ourselves. More recently, Anthony took a break to enjoy marriage and a new child, but he’s back working on new projects to post soon. Search for ThebuildTV, The firehouse Project.

Firepole Engineering: A Behind-the-Scenes Highlight

There are other videos worth watching about the Fire House. I particularly enjoyed the one about the firepole from his office to the garage below. I remember we worked around where it would go in our design layout, but Anthony had to solve several additional very tricky problems. These included getting the right product to provide both child safety and code requirements, as well as repositioning it when he changed the garage doors from old style swing out doors to an overhead door in an angled room, which changed the exact position of the fire pole pass through to clear the new overhead doors in a tight angled space. In that video, in addition to the retractable protection cage with retractable metal firestopping being just a very cool gizmo, you get to see Anthony’s mind almost transparently problem solving in his unique new abode.

If you want to read more about Anthony and the Firehouse check out this article featured on Dwell

Hoyt Corbett

ABOUT THE AUTHOR

Hoyt Corbett

Partner, Warm Brothers Inc.

Hoyt has been involved with hydronic heating since the early 1990s. He developed and sold a national brand of radiant floor heating that was acquired by Uponor, and served as a first Associate Director of the Radiant Panel Association, the industry’s trade group. Warm Brothers was founded in 200???, with a growing menu of quality radiant board products. They continue to innovate to this day.

Hoyt has done extensive technical writing on radiant floor heating, having written several design and installation manuals for major national hydronic heating vendors. He also created and published the industry’s first annual The Radiant Flooring Guideon choosing flooring materials for use over radiant floor heat.

Call Hoyt at 206-369-1458, 8am to 5pm PST.

Explaining the Incomparable Comfort of Radiant Heat

“You Can Feel It”: The Unspoken Comfort of Radiant Heat

“It is not warm air that makes you comfortable, but warm everything.” — James Cutler, Faia

“You can feel it the moment you walk into a room.” — Hilary Mackenzie, AIA

“Tell them it’s like the sun indoors.” — John Fantauzzi, Industry Innovator

More than 20 years ago I had the privilege of interviewing two well-known West Coast architects about their choice of radiant heating for their award-winning custom projects. Each had evolved their own vocabulary around the distinctive comfort of radiant heat, a comfort best explained by the concept of mean radiant temperature.

“You can feel it,” explains architect Hillary Mackenzie. “I have always tried to make ever better houses and buildings for my clients, and the quiet, even heat of radiant floors fits that goal. I have never had a client who didn’t love it… the comfort has a feel-good quality that is hard to describe in words, but you can feel it the moment you walk in the room.” ….So rather than simply describing the advantage of radiant heat, I recommend taking potential clients to a radiant floor-heated home, and let them feel it.

Nationally renowned architect James Cutler went beyond description of the heat itself, to explain why you feel that special quality in homes heated by hydronic radiant floors. He explained that about 98% of a home’s warmth is inherent in the mass of objects filling the interior space and radiating from surfaces, while only 2% typically comes from the heat capacity of air itself: “It is not warm air that makes you feel comfortable, but warm everything.” Cutler also appreciated that the lack of obtrusive duct work allowed him to concentrate on the bones of a structure.

Home’s warmth using the concept mean radiant temperature

Photo Credit Art Grice Courtesy of Cutler Anderson Architects

The idea that with radiantly heated interiors, “the warm everything” is what makes you so comfortable is technically understood in the industry via the concept of Mean Radiant Temperature or MRT.  

I used to say, “Premium homes deserve premium heat.” And then I’d explain MRT.

Mean Radiant Temperature refers to the average temperature of all the surfaces surrounding you, including walls, windows, floors, and ceilings, even cabinetry. It represents the combined effect of radiant heat coming from all these surfaces, all contributing to a person’s perception of comfort, whether warmth or coolness. Unlike air temperature (the temperature of the air around a person), MRT represents the radiant energy exchange between a person and surrounding surfaces.

Research on MRT, human metabolic rates, and comfort, has shown that—in most cases—people in a radiantly heated home are comfortable at lower air temperatures due to the higher average surface temperature near their bodies. Typically, in a forced air home, convection drives uneven air temperatures (heat rising, for instance), which results in uneven surface temperatures: the higher parts of a room are significantly hotter, whereas in a radiant floor heated home the heat begins beneath your feet and emanates everywhere.

In calculating MRT, it is typical to take into account the surface temperatures of various surfaces within the line of sight of the person, as well as the distance from these surfaces and their respective emissivity (how well they radiate heat). Clearly, these are not intuitive calculations, but they are of consequence: the results can be felt! Since the 3 dimensional computations are very complex it is hard to represent in a drawing. But it has been well confirmed with finite element analysis and thermal imaging. 

Mean Radiant Temperature, Comfort and Energy Efficiency

There is a strong relationship between Mean Radiant Temperature and comfort in radiant floor heated homes, since most of the heat is transferred directly to a person, metabolic research has also shown that in a radiantly heated home, if the MRT is below 64°-68°F, a person will likely feel cold. If you are aiming for a comfortable space, you would usually want to keep the MRT around 72°-75°F for most people, which aligns with a neutral metabolic comfort zone for indoor settings. The gift of radiant floor heating is that, due to the average surface temperatures at body level being warm.

Because of MRT most people feel comfortable at a lower air temperature than with forced air heat because of all the warm surfaces radiating heat. In a radiant heated room, the ideal condition for comfort occurs when the MRT is balanced so that there is not a big difference between what a person feels from the surrounding surfaces, and the ideal metabolic comfort ranges referenced above. The air temperature can be lower, and people will still be comfortable, as long as the MRT is higher and more consistent (steady), which is usually the case.

So maintaining a lower air temperature (than a conventional forced air system requires) saves energy, aided by the small circulating pumps required for hydronic radiant heat, and the inherent efficiencies of using the denser medium of water, versus air, to transfer heat. Forced air systems usually involve significant duct losses, and require much more fan energy to blow compressible air through big ducts. 

Think How the Sun Works

My friend John Fantauzzi—an early proponent of radiant heat and colleague in the Original Radiant Panel Association—suggested we tell potential clients: “Tell them it’s like the sun indoors.”  When I was a radiant floor heating contractor, I hadn’t used such a brilliantly simple image, but did tell potential customers to do a similar thought experiment: “Imagine you’re basking on a warm beach on a sunny day, all that sand and air warmed by the radiant heat from the sun.” Or, more personally, I would recount my experience as a professor at the University of New Mexico in Albuquerque:

In winter, our nights would often go down to 25°F then climb to 40°F by mid day. On the south side of the building where I taught, there was a courtyard between my building and a reservoir that had a high enough wall to protect the courtyard from the wind, but still allowed direct sunlight. That south-facing adobe-colored wall absorbed solar energy, its warmth radiating into my back as I sat in front of it, while the sun itself sent its radiant rays to warm my front side, too. I discovered that in this space that was radiantly heated from the sun, I could be comfortable on a 40° morning in a t-shirt!

Later, when I moved to the drearier winters in the Puget Sound, I was determined to bring some of that radiant sunlight with me. I built a house sited with southern exposure, with radiant floor heating that was exceptionally warm and comfortable. Our radiantly heated floors made us feel we’d brought some of the New Mexico sun north with us.

Cold the radiant floor in the winter Efficiency of radiant floor heating by the concept of Mean Radiant Temperature

In this home in the winter, on a cold day the radiant floor might be 78°F, but because the surfaces were all at a higher temperature than air temperature, we were almost always comfortable at 67°F-68°F air temperature in shorts and a T shirt.

There are many graphics (like the one shown below) that illustrate the how air temperature in a radiantly heated home is distributed significantly differently than that in most forced air interiors. These drawings make a good argument for the efficiency of radiant floor heating, and show the more even temperatures common with radiant heat, but they don’t explain it the way the concept of Mean Radiant Temperature does. 

In a radiantly heated home, Mean Radiant Temperature is what determines thermal comfort because it reflects the heat exchanged from surrounding surfaces to a person. Since this is a dynamic process that takes into account the radiant energy coming from every surface, in every direction, it is best felt and understood as a large, even, low- temperature surface which, unlike forced air, has an even lower temperature profile. It is incredibly quiet, saves energy, and perhaps best of all, it’s incredibly comfortable.  

 


Hoyt Corbett

ABOUT THE AUTHOR

Hoyt Corbett

Partner, Warm Brothers Inc.

Hoyt has been involved with hydronic heating since the early 1990’s and developed and sold a national brand of radiant floor heating that was acquired by Uponor. Subsequently, Hoyt was Associate Director of the Radiant Panel Association, the industry trade group.

He’s produced extensive technical writing on radiant floor heating, writing several major national hydronic vendor’s radiant heating design and installation manuals as well as founding and publishing The Radiant Flooring Guide.

Call Hoyt at 206-369-1458, 8am to 5pm central time

or

email him at: hoyt.corbett@warmbrothersinc.com

Hydronic Radiant Floor Heating Panel Types and Thermal Inertia

This blog is designed, in a commonsense way, to explain how different radiant panel types respond at different rates when charged with warm water. It will explore the applicable uses of different types of hydronic radiant panels and applicability of different controls to each type. 

Example of a high mass hydronic radiant panel system in a slab followed by a low mass example attached to a subfloor Followed By An Example of A Low Mass, Low Thermal Inertia Radiant Panel System.

Low Thermal Inertia Radiant Panel System.

 

Hydronic radiant panels

 

Radiant floor heating hydronic panels using a slab have a lot of thermal mass that must heat up or cool down to counter-act changing temperatures in a home or a building. A large mass of relatively dense concrete conducts the heat from the pipes to the surface which usually includes floor coverings from where it then radiates heat to the room.

Low mass, low thermal inertia panels are usually made by combining a low mass strata with a modest thickness of a very conductive material. Properly designed they heat up and cool down quickly. The high and low mass systems each have their place, but the differences are worth learning about for anyone contemplating or living in a radiantly heated home. 

For clarity, hydronic radiant panels used for hydronic heating transfers heat predominantly by radiation once the heat gets to the surface of the panel. Due to where it is used, the proportion of heat provided by a convective loop in a room is different for floor, wall and ceiling applications. All rooms are individual circumstances, but radiant floor heating panels may be 58% radiant and 42% convective, radiant wall panel wall may be 75% Radiant and 25% Convective while ceilings may be may 92% radiant and 8% convective. 

While the effects of placement of hydronic radiant panel are interesting, more important for this article is how fast a system responds to heating up and cooling down which is related to the panel’s thermal inertia.  In general low mass systems respond faster (heat up and cool down) faster provided they are conductive enough to move the needed amount of energy to the surface of the panel and then to radiate and heat the space. This is also termed the thermal inertia of the hydronic radiant panels or radiant board. 

In the context of hydronic radiant floor heating systems, thermal inertia can be described as the radiant panel system’s ability to store and slowly release heat. It is the resistance of the panel structure or the materials within it, such as concrete, wood aluminum and a variety of floor coverings to temperature changes. High mass radiant panel systems as exemplified by concrete slabs heat up slowly and cool down slowly. To affect changes in the surface temperature of such a system requires either heating up the whole mass of concrete to raise its temperature or waiting while the whole mass cools down. In a low mass hydronic radiant panel, when properly designed, will respond much faster both to heat up and cool down. Both types of systems have implications for control and application. 

In my early experience as a contractor there really were no “low mass, low thermal inertia” systems on the market. Hence I had a lot of experience with high mass, high thermal inertia systems. Later as part of this company, Warm Brothers Inc. We developed and patented a low mass, non structural radiant board called Thermalboard which is part of the growing portfolio of radiant boards, that our company  now makes and sells. So, I have a lot of experience with both high and low mass radiant systems and hope my experiences will be helpful.   

Radiant Heat Panels To Meet Most Radiant Heating Applications

Our radiant panels deliver efficient heating across multiple applications. We even have Low Mass radiant panals with EPS bonded to the bottom of panel for use over uninsulated concrete slabs. Visit www.wbiwarm.com  to see these products. One of my early projects was installing radiant floor heating in a two story building housing a dance studio and office on the ground floor and an office an apartment on the  apartmentn the second floor.

 

WBI radiant panels deliver efficient heating across multiple applications

 

Both floors can be described as high mass high thermal inertia systems. The first floor was a slab on grade. They were installed as shown below. The first floor installed with foam steel tubing and cement as shown. In addition there was a floating floor above the slab mounted on 2”x2”x2” foam cubes. This allowed the floor to flex to help prevent injuries of jumping up and down on hard floors. It worked by the concrete radiating heat to the suspended plywood floor which in turn radiated it to the whole room. Since the studios were not used 24 hours a day there was initially, a  desire to put a significant set-back when it was not used.

The disadvantages of a high mass system such as this is that it took about four hours to heat back up due to the amount of energy it took to charge the system back. And if the schedule of use changed without it having been anticipated, lightly clad dancers arrived and were cold. The second floor had somewhat less mass with tubing stapled to the subfloor and covered by 1-1/2” of six sack pea gravel mix of cement. It required a second bottom plate and had a similar recovery time profile. Later thermostats that had a learning “adaptive recovery” feature got better at timing setbacks. However, with time the dance studio adopted a “Set and Forget” approach where they did not use set-backs. This was not because it could not be set up with the right control to do setbacks but because the set-back schedule was not easily predicted. 

The time lag and thermal fly wheel aspects of slabs on grade make them easiest to control and use in climates with modest temperature swings, basements where temperature swings are moderated by stable ground temperatures, houses with overhangs that minimize solar gain, garages with few windows and in climates where with deliberate solar designs, the thermal mass of a slab can help store and redistribute solar gain. New technology has now made controlling slab-based hydronic radiant panels more reliable and efficient. And our newest panel, InsulHeat™ for use under slabs, has made installing a hydronic slab cost effective. . Here is a link to previous blog on the product: https://wbiwarm.com/blog/hydronic-radiant-floor-heating-in-concrete-slab/

Later Warm Brothers inc. patented Thermalboard™ a low mass, low thermal inertia product which has since been followed by Ecowarm® Radiantboard™ and many others. These systems have many advantages. Simply put they can quickly go through the stages of a radiant panel where it absorbs heat and releases it with out a long period charging a mass getting it to the point where it will release heat. 

Over Raised Floor Subfloor

Over Raised Floor Subfloor

 

Over Concrete Slab

Over Concrete Slab

 

Underslab insulated panels

Optimizing Hydronic Radiant Panels with Outdoor and Indoor Reset Controls

Both types of systems benefit from good controls. An outdoor reset control which adjusts water temperature according to the weather can get the BTU’s  being supplied to the heating system a close match tom the heating demand which reduces cycling, prolongs mechanical products and promotes even temperature change. They are very helpful in controlling slabs since once the right curve is found such a control is keeps temperature swings in a high mass system within a range that the fine tuning is then done by the thermostats. 

In the low mass board systems we sell, use of outdoor reset controls has a similar benefits and, in particular really helps bring traditional wood flooring systems through temperature changes slowly. The low mass boards we sell have a particular benefit that the quick recovery of the system means many  different setbacks and temperatures can be programmed in a day. So if you like the house warm when you wake up, cool while you are gone during the day, warm again for the evening and cool for sleeping a low mass product will easily do that.

Unlike a slab system, if an unexpected guest arrives and you need to quickly heat up the guest suite you can do that. Again thermostats that have adaptive recovery logic will make it work better. Maybe a way to think about it is that its has a bit of AI enabling it to get better at controlling your house. Properly controlled high mass systems can be very stable but are just hard to change quickly. There are climates in the United States that have a heating and cooling load in the same day….desert climates and the central valley of California come to mind. Paying to cool a high mass system that you earlier in the day paid to heat makes absolutely no sense and hence should utilize low mass radiant panel systems. 

There are also Indoor Reset Controls which alter the watger temperature based on room temperature. They do not take into account the effects of dramatic weather temperature changes the way an outdoor reset control does. This can be a problem with high mass systems where if the oudoor temperature drops dramatically it will show only later in the room temperature dropping putting a slower responding system behind in catching up. 

There are also floor and slab sensing thermostats and some ones that can control both.  Usually, the floor sensor is essentially a safety for floor coverings that have a maximum allowed temperature.

 

 


Hoyt Corbett

ABOUT THE AUTHOR

Hoyt Corbett

Partner, Warm Brothers Inc.

Hoyt has been involved with hydronic heating since the early 1990’s and developed and sold a national brand of radiant floor heating that was acquired by Uponor. Subsequently, Hoyt was Associate Director of the Radiant Panel Association, the industry trade group.

He’s produced extensive technical writing on radiant floor heating, writing several major national hydronic vendor’s radiant heating design and installation manuals as well as founding and publishing The Radiant Flooring Guide.

Call Hoyt at 206-369-1458, 8am to 5pm PST

or

email him at: hoyt.corbett@warmbrothersinc.com