Whether an air conditioner, heat pump or evaporative cooler is best for your home depends a lot on the size of your home, how many people are in your family and your budget. Without knowing any of those factors, let’s assume your biggest concern is living comfortably with a somewhat limited budget.

In this case, your best bet in Phoenix is an evaporative cooler. Phoenix has a dry enough climate that an evaporative cooler will effectively lower the temperature in your home. On average, the relative humidity in Phoenix during the summer months is around 20 percent. If the outdoor temperature were 90 degrees Fahrenheit, then an evaporative cooler would be able to lower the temperature of the air to 70 degrees.

Evaporative coolers are a very efficient way to lower your home’s temperature because they essentially force hot, dry air through water-soaked pads that add moisture and reduce the temperature of the air. These systems work best with a well-installed ventilation system; for example, a whole-house fan could be used to circulate the cooled air. Overall, evaporative coolers are two to three times more efficient than the most efficient central air conditioner; however, the degree to which they can lower temperature depends on how dry the air is and the temperature outdoors.

From there, if you live alone, you may want to invest in one or two room air conditioners with high EER ratings. If you have a big family, you could invest in a central air conditioner with as high of a SEER rating as you can afford. Although a higher SEER rating will raise the upfront cost of your central A/C, you’ll save enough more money on your utility bills in the years following to pay off the difference several times over.

Finally, you may want to consider a heat pump. Heat pumps are a great investment because they work as both an air conditioner and a furnace. Heat pumps are more expensive, but they’re also more efficient, which will be reflected on your utility bills. As an air conditioner, they essentially work the same as a central A/C by extracting heat from the air inside your home and pump it outdoors. In the winter, they extract heat from outdoors and pump inside your home.

For more information about energy-efficient ways to cool your home, check out our Home Air Conditioning topic page. There may also be to help you cover the costs.