I was wondering if anyone could help me with this error, TREAT is saying that the primary heating system capacity adjusted by distribution and heating safety factor exceeds its assigned share of building load by more than 50%.
The heating information came from the energy audit, so I am not sure how I can correct this error. Any help will be greatly appreciated,
Luis, Good Evening, John of NY Construction Pros here.
I don't think you need to worry about this warning from TREAT too much. All it means (as I understand it) is that the primary heating appliance is too large in its Btu capacity for the house. I get this warning often. We ignore it. If you receive the other warning; that the capacity is TOO SMALL, this matters but if it is to big, it doesn't matter. Check with PSD Consulting for the definitive answer but I say, don't worry. I hope this helps.
John WL, Yorktown heights NY.
It is very common to find equipment grossly oversized. I mean 1.5 - 2x Manual J and 2-3x the size the house needs.
It's our experience that TREAT load calc is very close to Manual J - which tends to oversize equipment by 15-40% depending upon how well you intend to fix the home.
(Just one of many examples - I have a client with a 6500 sf 1920's brick mansion that the load calc is 140,000 btu, and the house carries 70° to 5° f outdoor with roughly 60,000 btu. We can prove this through Ecobee logging: http://bit.ly/4ecobeethermostats - And this house still has leakage in excess of 5000cfm50.)
We have realized tremendous comfort and energy savings from aggressively downsizing. Our process is to downsize equipment until we get an undersized warning, then we know we are in the ballpark. If you don't get an undersized warning you are probably too big.
We don't have outdoor ductwork in our area. I would be very careful doing this with outdoor duct unless you are sealing and insulating on levels similar to these guys: http://bit.ly/ring4club