Quick System Selector

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House Location

(use map below)

House Square Footage


Need Help Sizing Your Equipment? Click Here

Simple AC Selector: Use the map above to find what zone you live in. In the table below, click on the square footage of your house and the zone you are in to see a list of units that will work best for your home.

1.5 Tons600 - 900 sf600 - 950 sf600 - 1000 sf700 - 1050 sf700 - 1100 sf
2 Tons901 - 1200 sf951 - 1250 sf1001 - 1300 sf1051 - 1350 sf1101 - 1400 sf
2.5 Tons1201 - 1500 sf1251 - 1550 sf1301 - 1600 sf1351 - 1600 sf1401 - 1650 sf
3 Tons1501 - 1800 sf1501 - 1850 sf1601 - 1900 sf1601 - 2000 sf1651 - 2100 sf
3.5 Tons1801 - 2100 sf1851 - 2150 sf1901 - 2200 sf2001 - 2250 sf2101 - 2300 sf
4 Tons2101 - 2400 sf2151 - 2500 sf2201 - 2600 sf2251 - 2700 sf2301 - 2700 sf
5 Tons2401 - 3000 sf2501 - 3100 sf2601 - 3200 sf2751 - 3300 sf2701 - 3300 sf


Proper System Sizing

In order to scientifically calculate the right central air conditioner size, you can perform a Residential Load Calculation.

Another way to size air conditioners is to determine the system size that is currently in place. The manufacturers do not list the air conditioner size on the unit. The system capacity will be coded into the model number of the outdoor unit.

Use the following conversion information to determine your existing system size (use the system model number NOT the serial number)

18 = 1.5 tons
24 = 2 tons
30 = 2.5 tons
36 = 3 tons
42 = 3.5 tons
48 = 4 tons
60 = 5 tons

When sizing air conditioners, be careful not to make the mistake of getting one that is too large. If the system you install is too large for the space, it will short cycle. In other words, the compressor will not run long enough to dehumidify the space and will limit your comfort. In addition, it will cycle on and off more frequently, increasing operating costs and reducing the system life. Proper air conditioner sizing is critical to optimize performance.

Heating Square Footage By Climate Zone

30 - 35 Btu's per square foot35 - 40 Btu's per square foot40 - 45 Btu's per square foot45 - 50 Btu's per square foot50 - 60 Btu's per square foot


Heating Guide

Use the lower of the two numbers if your home is well insulated and the higher number if it is older or poorly insulated. (Hint: Use the larger of the two numbers above if you're unsure of your home's insulation)

Simply multiply the appropriate factor above by your home's total heated square footage to arrive at your approximate required heating capacity. For example, if you live in the yellow zone, your home is well insulated, and you have 2000 heated square feet, the equation will look like this:

2000 square feet
X 40 heating factor (from the chart above)
80,000 Btu actual output

Then, to calculate the output on a gas furnace, multiply its efficiency rating by its listed input rating for the actual Btu output of heat. For example, if a furnace has a listed input rating of 100,000 Btu's and an efficiency rating of 80%, it will produce

100,000 Btu input
X .80 efficiency
80,000 Btu actual output

If the same 100,000 Btu furnace has an efficiency rating of 93% it will produce:

100,000 Btu input
X .93 efficiency
93,000 Btu actual output

For this example, using an 80% efficient furnace, the 2000 square foot home above would require a 100,000 Btu input furnace which will produce the necessary 80,000 Btu's output of heat.


Variables such as your insulation, type and number of windows, number of stories, construction type, etc. will greatly affect the required Btu's per square for both heating and cooling. A general rule of thumb is that if your home is well insulated with newer style windows, you can select the smaller size system that falls within your total square footage.

If your home is two story it will place less of a load on the system in the downstairs area as the second floor acts as additional insulation. If your home is not well insulated, has older style windows, and/or a larger than average number of windows, you will want to select the larger system which falls within your square footage range. The less insulated and more windows within the environment, the more likely you will experience greater air and heat loss.


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