I’ve posted these questions to the Saturn online forums, but there’s not much activity over there. Definitely appears to be different here…

I’m new to the forum, so if there’s a more appropriate place for this type question, please feel free to steer my in the right direction…

I’m looking at page 269 of RE (Residential Energy by John Krigger and Chris Dorsi) and trying to determine how they arrived at 88,300 for BTU/ft2/yr

My calculations get:

782 therms * 100,000 = 78200000 BTU

78200000 btu /1590 sq/ft = 49182 btu/ft2/yr

???

Another thing I’m puzzled by is that the heating therms calculation is 782 in the “Separating Gas into Heating and DHW” section, but he uses 823 in the lower section “Energy Consumption Summary…”

Also, he uses 304 therms in the bottom section for Water Heating, but the calculation uses 345

Can anyone help me sort it out?