It's easy to answer how many square feet a 3-ton air conditioner can cool. According to the general rule of 20 BTU per square foot, a 3-ton air conditioner can cool spaces of approximately 1,800 square feet. You can find the best central air conditioners with prices for 2, 3, 4, 5 and 6 ton air conditioning units here. In general, in temperate climates, a 3-ton AC unit is enough to cool a home of between 2,000 and 2,200 square feet.
However, in hot climates with lots of sunlight, a 3-ton air conditioner may struggle to cool a house of this size. Smaller homes are easier to cool. The recommended capacity for a 1,201 to 1,500 square foot home is 2.5 tons and for a 1,501 to 1,800 house is 3 tons. For a 2,000-square-foot home, the best air conditioning capacity is 3.5 tons and for a 3,000-square-foot home you'll need a 5-ton unit. The amount of cooling energy required to adequately cool a home between 1,200 and 2,400 square feet depends on several factors such as the local climate, house size and insulation.
A certified HVAC technician must calculate the load based on these factors. Overworking the air conditioner can result in more frequent repairs and expensive components replacement. In order to determine the right size for your home you should call local HVAC companies or fill out this form and get free warehouse information and quotes. Depending on the specific features of your unit and your home's wiring configuration you may need to use a larger switch such as 40-amp or 50-amp bipolar switch. For example, for a normal 8-foot house with a 1,370 square foot roof a 3.5-ton heat pump would suffice even in Arizona. The best brands usually have a lifespan of 20 or even 25 years but if you need it for 10 to 12 years you can opt for cheaper Goodman or Rheem units.
You probably need a little more tonnage for heating but you can use cheap 1500 W space heaters to supplement your main heating system.
