2 tons or 5 tons?

Question

How do you know what tonage a/c unit you need to purchase? I'm doing a little research before buying, but I am lost as to how much my house needs.

Answer 1

YOU WILL BE DISAPPOINTED IF YOU OVERSIZE THE UNIT. About 600 sf per ton is a good estimate assuming reasonably good insulation particularly in the attic and on the south wall.

IF YOU OVERSIZE the unit its cycle will not permit efficient DEHUMIDIFICATION. Properly sized air conditioners are extremely good dehumidifiers and humidity control is a Major comfort factor.

Answer 2

Always upsize your unit to the next size. I have seen people install the 3 ton units and it runs at 100% to keep the cooling load handled. Same with heat. I say go one size larger so you can have a unit that runs at 75%. May not seem cost effective but it works out.

Also if you ever plan on adding a room or converting a garage into a room you definatley need to upgrade. I have 3 co-workers who have done home additions and ended up replacing a unit with a larger sized unit because they didn't get one ahead of time.

mike

Answer 3

It depends on the square footage of your house,
and what climate you live in.
Typically a 2000 sf home would use a 5 ton unit.
A 1200 sf home would use a 2 or 3 ton unit.
There are many factors to figure -
Most important - actual sq feet you want to cool/heat, this may differ due to you may not want to include your basement or laundry rooms - etc...
Contact your local electric company or a HVAC contractor and they will gladly formulate your needs for free.
Also if you will need a lot of heat in winter - then look into units with heat pump.

Answer 4

Each ton is 12,000 btu's. You need to have a "heat gain" done on your home to determine how many btu's it's going to take to cool your home. You should have this done by a professional. Get the most efficient unit you can afford for the greatest savings. The heat gain is just a bunch of questions about your home. size of the rooms, type of windows, amount of insulation, etc.

Answer 5

My city offers a free Energy Audit. Basically, they pay for local contractors to come in and tell you what you need, what credits and rebates you can get, etc. They should be able to plug your house into a formula and tell you what you need.

I have seen other cities offer similar programs so you might talk to your local electric company and see what they offer.

Don't just ask a HVAC contractor you hire out of the phone book. A friend did that and ended up with a system way too large for his house (meaning he doesn't qualify for many rebates, etc).