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First Choice Heating & Cooling Blog

Let’s Talk About Your the Limits of Your AC

advanced-thermostat-on-hot-dayYou know that you can’t press down the pedal of a car and expect it to accelerate forever. The car’s motor has a top speed, a point where it mechanically cannot put out more power. The same applies to your home’s air conditioner. Even if the thermostat lets you set a temperature lower than 60°F (the standard lowest setting), you couldn’t keep making your house colder and colder until you could freeze ice cream in it. 

Of course, you don’t want your house this cold—but how cold can you make it? 

Knowing the answer to this question can help you in the future with setting your thermostat and avoiding placing strain on the AC. Below we’re going to look at the cooling limitations of your AC, it’s “maximum speed.”

How Cold Can My AC Make My Home?

Based on the thermostat, you can’t lower the temperature of the house below 60°F. But that’s just a limit set by the thermostat. The mechanical limit of the air conditioner is its temperature differential. The air conditioner doesn’t have a lower limit on how cold it could make the house, but it has a limit on how much it can change the indoor temperature compared to the outdoor temperature. In other words, the cooling difference the AC can make. 

Your air conditioner, like all other residential air conditioners, has a temperature differential of 20°. It can lower the indoor temperature of your house 20° below the temperature outside. And for our local weather, that’s usually more than enough!

We’ll use an example for a Flushing, MI, HVAC system based on average summer heat. July is the hottest month in Flushing, with an average high of 82°F. The temperature rarely reaches 90°F. On an 82°F day, an air conditioner with a 20° temperature differential can make a house 62°F—colder than most people find comfortable. Since the recommended energy-saving setting on a thermostat for the daytime when people are home is 78°F, an air conditioner will have no problem keeping a home cool at the peak of summer. Even on the odd 90°F day, an AC can cool a house down to 70°F—still more than cool enough. 

If Your AC Isn’t Meeting the Requirements

You’ve read the above, you know about temperature differential … and yet when you set the thermostat to a temperature the air conditioner should be able to handle without strain, the house still doesn’t feel cool enough. If this happens to you, there’s either something wrong with the AC or the thermostat.

One possibility is that the AC is undersized for the house. The temperature differential only applies if the air conditioner was correctly sized at installation so it can put out enough cooling for the space to lower it by 20°. If you have a new AC that isn’t keeping up and runs continuously, then it’s likely an amateur installed it. The only solution to this is to have a professional replace the system.

If the AC isn’t new, then the best approach when it can’t keep up with your cooling needs is to call our technicians. We’ll find out if there’s a malfunction and have it fixed so your AC will do the job you need from it.

First Choice Heating & Cooling serves Fenton, Linden, Holly, and the Surrounding Areas. If your home had a voice … it would call First Choice!

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