View Full Version : online heat loss calc???

07-21-2010, 07:30 AM
Hey guys, is there an easy to understand heat loss calc online I can use for my house before I buy a boiler??? Last year I had 6 diff plumbers at my brothers house for a new boiler and none of them even measured the house for a heat loss. they didnt even ask me what was in the walls! So, not trusting any of them I would like to do it myself on my house. Any help would be appreciated!


07-22-2010, 04:29 AM
Take a look at :


Nate R
07-22-2010, 04:44 AM
I use ResCheck to run heat loss calcs.

This is a program by DOE used to check code compliance for energy use of buildings.



Figured out that my current furnace is pretty oversized, and once I change the windows, add insulation around the foundation and air seal, I'll be moving down to a smaller furnace.

07-22-2010, 09:01 AM
Thanks guys, Nate I am going to try your calc first, may ask what this means though " Enter or calculate the maximum glazing area, defined as the sum of all glazing (including windows, sliding glass doors, skylights and windows in conditioned basements) divided by the gross wall area (excluding basement walls) expressed as a percentage." What is glazing???

07-22-2010, 09:53 AM
Don't you use Google? A dictionary would help, too. Glazing is the glass. They want to know what percentage of the wall is covered by glass verses a wall that has better (hopefully, anyway) insulation in it.

07-22-2010, 09:32 PM
thanks Jim, will do the calcs this weekend.