Heat Loss Calculations

Paul B

Are any of you folks familar with heat loss calculations? I have a couple of different programs I am trying to use but none of them have very clear directions. When they ask for the wall area, it does not specify if it is the exterior wall area or the total wall area. Certainly exterior walls would have a greater loss then interior. Also ceiling and floors, they do not ask if it is a single or two story house. Heat loss for the first story ceiling would be negligible where as the second would be greater.

Can anyone help me out here?

mdshunk

use www.heatload.com and enter through "school pass". Just pick a school.

nhmaster3015

Loss calculations are always based on exterior walls only. 2nd floor calculations are figured same as 1st floor.

www.slantfin.com free software

Paul B

So you are saying the heat loss thru the first floor ceiling with heated space above is the same as the second floor with unheated attic space above.

That don't make sense to me but it might be correct.

flashheatingand

The first floor is over an unconditioned space whereas the second floor is over a conditioned space. Also, it is likely that the first floor has more windows and doors than the upstairs. Thus, the loss is likely to be higher on the first floor as opposed to the second floor. The programs for sizing just want exterrior walls. Break down the house as a square, walls N,S,E,W.. Note the windows and doors, make sure you have the correct r- value for the insulation, and you should be good.

Good luck

Paul B

Thanks Guys

Paul

Warmsmeallup

Think of it this way; A heat loss calc is based solely on the areas that loose heat. Interior walls that have heat on the other side are not used in the calculation unless they border an unheated space. The same goes for the floors and ceilings. Like FLASH said, enter the correct 'R's and correct window and door sizes. The most important concept in HLC's is this : garbage in/garbage out.