There are a number of factors to the correct answer. The best accurate answer is to have a load J done.I have a 1400sqft home and need to know what ton I would need for AC. Also, my back room gets less air and is always hot. What could be or not be happenning?
:no: you don't even know where he lives. how can you tell?500 sq ft per ton close enough for 3 ton
However be careful you need to mke sure your existing duct work is sized for 3 tn both supply and return.
For example if you have now a 2.5 tn and want to increase in size need to double check.
For new install you can size as you go
Probably that it needs its own window AC orI live in south Texas and the back room is facing south, southwest. What would this mean.
.......a favor & get a pro to run a load calc. on your house. no one here can do that properly sitting behind a computer . the ductwork , furnace , envelope , have all got to be evaluated so there are no surprizes at EXPENSIVE unit startups when it's too late. I know this is a diy site , but this part is definitely out of bounds for diy. Please err on the side of caution & get a pro as there are factors involved you may miss and then your family will be throwing darts at you when they're sweating all summer.....regards...............:yes: JackI have a 1400sqft home and need to know what ton I would need for AC. Also, my back room gets less air and is always hot. What could be or not be happenning?