Environmental Solutions and Service | Specializing in Air Conditioning Maintenance and Indoor Air Quality

At Myers heating and air we use building science to solve our customers’ problems. One common question we get regarding heating and air conditioning, is what is the best temperature to set my unit during the air conditioning season which is typically during summer or the hotter times of the year?

First, we need to understand how the air conditioner works. In basic terms, the air conditioner is a black box that puts out cold air and generates water. The system is designed to remove just a little more water than it creates. If we set the thermostat too high during the summer, than the unit will not stay on long enough to effectively remove the moisture it is creating, which can lead to short cycling of the system, excessive ware and tear as well as high humid conditions. Theoretically, 78 degrees Fahrenheit is a common maximum temperature. Although, you should not look at this maximum temperature as a firm number, because all thermostat technologies are different.

So how do you know if you are short cycling or not running the unit long enough to make sure the appropriate amounts of moisture are removed? The outside condenser should run a minimum of 30 minutes every time the system comes on before it shuts off. If your system is running less than this between times of operation this is a good sign you may be short cycling.

On the other hand, If we set the thermostat too low, then we can create a situation where we run the air conditioner to saturation. This means we are running it to the point where the unit is creating more water than it can remove. We find this condition happens when a home owner or occupant routinely keeps the thermostat set below 73 degrees theorectically.

With either of these situations, when they occur the result is moisture being throwndown the duct work. Moisture thrown down the ductwork can lead to the development of bacteria. If this condition is left unchecked, mold can develop as a result in the ductwork and eventually in the home. We often find that the occupants are having allergic symptoms related to bacteria within the home long before the mold develops. When looking at what temperature is appropriate, we recommend keeping it between 74 and 76 degrees Fahrenheit.

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