Now Hiring! See our open positions. Read More

Skip navigation


Serving The Twin Cities Since 1991


Residential Heating and Air Conditioning Blog

How Cool Can My AC Make My House?


This is a good question to ask, because answering it gives us a chance as HVAC professionals to explain more about what an air conditioner does and doesn’t do. Any air conditioner has limits, and when you understand what those limits are and why they exist, you’ll have an easier time finding the ideal comfort settings during the summer.

We’ll use our expertise at air conditioning in Minneapolis, MN to answer your questions about your AC’s power.

Cooling Limits

You probably have a general idea of the limitations of your air conditioning system. You only need to look at the thermostat to see that it has a lower limit, usually 60°F. We hope you don’t want your house colder than that!

But could you potentially make it colder than that if the thermostat let you set it to a lower temperature? And is it possible to make your home as cold as the inside of a freezer? Most likely not, and we’ll explain more about that, but first, a note about the thermostat itself…

A thermostat isn’t a throttle that makes an air conditioner generate more or less cooling. Rather, it’s a switch that tells the AC when to turn the compressor on and off. When you push the thermostat down as low as it can go, such as 60°F, you’re only making the air conditioner run for longer as it attempts to reach that target. This isn’t related to how much heat the AC can remove from the air, which is our next topic.

The AC’s Temperature Differential

An air conditioning system doesn’t “create” cooling, since cooling isn’t a form of energy but a lack of heat energy. What a central air conditioner does is pump heat out of the house and then blow around the cooled air left behind. How much heat an air conditioning system can pump out sets its cooling limitation, and this is known as its temperature differential.

The temperature differential is how many degrees an air conditioner can lower the temperature of the air that it draws in through the return air vents. A residential air conditioning system has a temperature differential of 20°F. I.e., your AC can make the air in the house a maximum of 20° lower than what it currently is. 

Let’s say on a hot day when the temperature outdoors is 88°F, your house is about 82°F (thanks to the insulation that slows down heat gain). This means your air conditioner could potentially lower the indoor temperature to 62°F at most. That’s far more than you need for comfort, and we don’t recommend setting the AC any lower than 68°F to keep it from freezing up.

But you can see that your AC’s temperature differential is enough to handle just about any hot day. Even if the temperature is above 100°F outside, the indoors will be cooler and you can easily get the temperature down to an energy-saving 78°F.

If for any reason your AC can’t keep up with the heat, it’s likely it has a malfunction. Call our technicians and they’ll find out the repairs necessary to get your cooling back.

Contact Residential Heating and Air Conditioning and Feel the Difference!

Comments are closed.