USA
Canada
What is distribution efficiency and why does it matter?
The latter criteria can be quantified using an index called distribution efficiency, which can be defined as follows: Distribution efficiency has nothing to do with converting any type of fuel into heat. Instead, it describes how many Btu/h of heat the distribution system can move from the heat source to the heat emitters for each watt of electrical power supplied to operate that distribution system.
The more heat the distribution system can deliver per watt of electrical power demand, the higher its distribution efficiency. Here’s an example: Consider a hydronic system that delivers 120,000 Btu/h at design-load conditions using four circulators operating at 85 watts each.
Hydronic Distribution Example 1The distribution efficiency of that system is: But is 353 Btu/h/watt an acceptably high value for distribution efficiency? It’s hard to judge a number for any physical measurement without something to compare it to. Here is a similar calculation for a furnace with a blower that operates at 850 watts while delivering 80,000 Btu/h through a forced-air ducting system:
Hydronic Distribution Example 2Hydronic systems are far more efficient than forced air
For these two examples, the hydronic system provides a distribution efficiency about 3.8 times higher than that of the forced-air system. That distinct advantage is the direct result of water being far superior to air as a material for absorbing heat. Using modern hardware and careful design, it’s possible to create hydronic distribution systems with distribution efficiencies well beyond the 353 Btu/h/watt value of the previous example.
Hydronic heating is simply more efficient. Add to this inherent system distribution efficiency a low supply water temperature product like Ecowarm RadiantBoard and you have it nailed!
About The Author
