Maybe it’s just us, but my spouse and I can never agree on how to set the thermostat. 

He likes it arctically cold, I like it nice and warm, and we constantly change the settings when we think the other isn’t looking! Unfortunately, this back and forth just put a strain on our own interactions and on our poor AC unit.

Far better for us (and the unit!) to agree on a middle temperature and then leave the AC to do its thing. We’ll be happier not constantly “fixing” each other’s temperature adjustments and the unit won’t have to work as hard, making it more energy-efficient and extending its lifespan.

Downsides of a fluctuating temperature

The main downside to constantly turning on and off your AC is wear and tear on the unit itself. Like most electronics, it suffers from turning on and off too frequently and the parts quickly wear down, especially because the machine works hardest when you first turn it on.

Constant jumps in the temperature setting can have a similar effect if they occur often enough. This means that your AC unit is working too hard and will wear down more quickly, leading to costly repairs and early replacement.

Closely linked to this is the amount of energy the unit uses when it is working hard. Your unit works hardest when the temperature settings are changing. The harder your unit is working, the more energy it expends, potentially adding hundreds to your utility bill every summer.

Benefits of keeping a relatively constant temperature

Alongside substantially lowering your energy costs and extending the lifespan of your AC unit, there can be additional benefits to your home such as keeping your hardwood floors and wooden furniture in better condition.

Rapid changes in temperature and humidity, like when the AC gets shut on and off, cause natural woods to expand and contract, slowly wearing them down, loosening joints, and generally making them lose their luster. Fluctuating temperatures can also have an effect on your mood and how well you sleep. Our bodies function best with consistency and rhythm.

And when I say relatively constant, there’s an emphasis on “relatively.” Refraining from flipping your AC on and off throughout the day does not mean that the temperature has to stay absolutely constant, just that you should avoid drastic changes on a regular basis. If there is no one home during the day, for instance, you could leave the AC set a few degrees warmer so that the unit isn’t working as hard with no one around to enjoy it, and then set it back at a comfortable setting when you get home.

If you are only running errands for an hour or two, it’s better to leave the settings alone, but if you are gone for an 8-hour workday or on vacation, then it is probably best to reduce the burden on your unit. The key to making these determinations is to consider what will make the AC unit work less.

Generally speaking, it is easier on the machine to maintain a steady temperature than to be turned on and off several times throughout the day. A programmable thermostat is a great advantage here and can help you keep your temperature steady and energy costs low.

How to Resolve Thermostate Wars with your Partner

If frequent changes to the thermostat are bad for the unit, what are some alternatives for helping everyone be more comfortable with the temperature? 

A first step is to determine if your home has some rooms that are warmer or cooler than the setting on the central thermostat.  If you like things on the cooler side, but work from home in an office with a wall full of windows facing south, that room will be much warmer than the basement space where your partner is feeling rather chilly.  In such situations, the problem isn’t the temperature setting, but rather the heating/cooling lost in that particular location.  Rather than throwing off the rest of the house, address the root cause of the temperature difference in that room.  Is it a lack of insulation,  poor return air flow, or maybe even something as simple as the vents are partially closed in that room.    


If you have any questions about the best temperature to set your thermostat or how to help the temperature be consistent throughout your home, please feel free to give Twin Air a call at (703) 754-1062 or contact us on our website.  Our HVAC experts will perform a thorough evaluation of your home’s system, insulation, ductwork and more. In some cases we can identify simple fixes to address your problems. Whether it’s a big or small challenge, our team will help you find the most cost-effective and efficient solution.

This article was originally published on June 14th, 2018 and has been revised and updated in July of 2022 to include additional information.


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