CENTRAL AC SQ Feet/#Ton Unit

Okay so i am getting quotes for central air and aside from price, my question is the whole square feet of living space and how many ton unit. My sil house is a ranch (mine is too) and she has a 4 1/2 ton unit and her house is approx. 200 feet larger. but i am getting quotes telling me to go with 2 ton unit, one a 2.5 ton unit and another guy 3 ton unit. does this even make sense? they are measuring so i don't know why so much difference. and i even asked the central ac guy if i had an extra 200 sq feet how much larger my unit and he says 3 ton so i am totally confused. did someone pull something over on her?? b/c people don't try to sell you things that cost less if they are trying to pull something over on you.

second question would be, is bigger better? my husband thinks we should get a larger unit than they recommend for our home. anyone who bought the unit size recommend please tel me how comfy your home is. (i've been told if you go with a larger unit your house will feel cold and clamy)

thanks everyone.

Re: CENTRAL AC SQ Feet/#Ton Unit

We learned so much when we had some companies in last year to give us quotes, plus it helps I am an engineer and studies this in school (albeit years ago!).

We have an 1880 sq. ft. hi-ranch and we have a 3 ton, 14-seer unit. We could have done 3.5 ton, but chose a 3 ton unit instead because we were replaceing our furnace as well (our central air runs off our furnace, not an air handler). We had it on all last summer and it was great, kept our home very comfy at 74-76 degrees (U think).

ETA: 4.5 ton is rather large, what is the sq. footage of her house?

Message edited 4/2/2007 11:25:56 PM.