your best thing to do is have a heating and ac contractor come out and tell them you would like them to run a load calculation and submit it to you with there price everyone gives free est. if they don't do not use them I run load calc. on every house we do and by state code you have to. There is no rule of thumb in this they can and will take your state lic.
1,200
3,100
900 square feet
Rule of thumb is 1.5 tons per 1000 square feet of home.
to calulate your btu needs,you can use this link: http://hearth.com/calc/btucalc.html
It depends on the width of the carpet.
My home needs ventilation. What size attic fan would I need for a 1200 square foot house?
1,680 square feet.
75,000 square feet
ranch style home - 1500 square foot with partial basement. What size generator would be needed?
14ft x 76 ft = 1064 square feet.
There's no way to calculate that just from square footage.
14 feet x 70 feet = 980 square feet.
32 x 70 = 2,240 square feet.
28 × 76 = 2128 square feet.
3,100
1,200