Replies

1. 
   BG | Jan 03, 2006 10:49pm | #1

   ArtD,
   I'll give you a few of the coefficients and you can do the math. Remember, however, you'll be estimating the heat loss from your space. We used to double the number for the size heating unit that was required so you would not have to spend hours waiting for the space to achieve the desired comfort level.
   In an insulated building the heat loss is:
   7 BTU's for every sq.ft. of outside wall space and floor space
   9 BTU's for every sq.ft. of ceiling space
   80 BTU's for every sq.ft. of glass
   We would add that up and double it for the air changes per hour(assume 2)and the total is the heat loss estimate.

2. 
   polarsea1 | Jan 03, 2006 11:39pm | #2

   Here's a site where you can download a program that will calculate your BTU requirements based on your location, insulation, etc.

   http://www.slantfin.com/he2/

3. 
   SteveSchoene | Jan 04, 2006 04:11am | #3

   Ask the HVAC guy about his ACCA manual J and Manual S calculations.  Those the full bore methods for calculating loads and sizing systems respectively.  There is lots of software out there for doing the calculations, and a pro ought have a program that he can use in his sleep.