On Sat, 16 Feb 2008 22:57:32 GMT, Donna Ohl, Grady Volunteer Coordinator
wrote:
I would guess any engineer should be able to tell us what this 41,045 magic
number really is.

I'm surprised a chemist or engineer isn't on this group.

I think this is the fundamental answer!

page 11, Water Heating Calculations
http://www.green-trust.org/2000/solar/solar.pdf
43,302 kJ/day is 41,045 Btu/day is the energy delivered to the hot water
load per day

And, this one says most plumbers don't understand the efficiency factor for
home water heaters

Residential Gas Water Heating:
Program Design & Specification Considerations, page 6
http://www.cee1.org/cee/mtg/09-07ppt...%20heating.ppt
Annual Savings (Therms/year) is based on the DOE Test Procedu
(41,045 Btu/EF*365)/100,000