What is the max square feet or cubic feet for residential air conditioners?

@JLeslie This Link seems to keep is simple and I like that it is tabled by temp zones.

@Cruiser That is helpful. I wonder if the high ceilings don’t matter much for air? I know that space with tall ceilings will be freezing on very cold days, which worries me a little, the heat will all be up in the ceiling.

@JLeslie That is why I run ceiling fans in reverse on low on cold days. I also close down unused rooms by shutting shades and vents that helps keep used rooms cozier. I also change the furnace filter at least twice in the winter and that seems to make a huge difference in keeping the air moving with most efficiency.

I believe that there are two additional factors:

Of your 2500 sf house, is it a ranch, a spilt level, or a two story? My recollection is that one zone in a two story is not advisable.

Second, and more important – how is your duct work laid out? Is it laid out for two zones (two compressors, two etc.) or is laid out as a single system? If the ducts are laid out as a single system, all the compressor in the world isn’t going to improve things.

@Cruiser I never close off any areas when it comes to air conditioning the house, but I do when heating. I live in a humid, hot, climate most of the year, so keeping the temp down and the air relatively dry is important. I keep my air conditioner usually around 77, which I think is warmer than where most people keep it. The filters are changed regularly. Every 1–3 months depending on the filter. You can’t let that slide in FL for mold concerns. The house won’t get tons of sun. The master bedroom is on the hot western side, which I am actually glad about. Unfortunately, my backyard is north, which isn’t terrible, but the most desirable is south. The back of the house also has a 12 foot deep covered patio, so the sun doesn’t come into the part of house with the most windows, I just hope it is enough light to feel open and airy.

@elbanditoroso The house is almst 4,000 sq ft and is a ranch. I need to actually calculate the zones, but I think they will work out to 1500 and 2500. I hope so. I think that would be a good split. The master will be in the smaller zone and that is my biggest concern for heating, because our days in the Tampa, FL are fairly warm even in the winter, but at night can get very cold. It’s a new house so the duct work is what I am talking about. You can’t have two zones unless you actually have two zones; two systems.