I did a heat loss calculation from HVAC computer systems, great program, one thing I am unclear of there are two large rooms in my house that were an addition and the previous owner never ran ducting to them ( use electric and on has a fireplace) would I include these rooms in my calculations???
Yep. If they have exposed walls heat will radiate thru them and will add load to the furnace/unit when the supplemental heat is Off. They also add to the cooling load. Do the calculation both ways and see how big a difference there is. You may want to get Pro to assess your ductwork size for a new furnace B4 replacing it if you have it for supplemental heat/dual fuel. Depending on your climate a smaller furnace may be okay. A 2 or 3 stage furnace may also help as it runs longer and uses less gas. Heat loss calcs are not gospel and an experienced tech can help determine the proper size.
"Cut it twice and it is still too short".
Last edited by yuri; 05-25-2010 at 09:50 AM.
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