Q: Should I turn off my air conditioning when I go on summer vacation?
A: Shutting off your air conditioning will save money on your electric bill, but there is also a reasonable chance you will have to spend a lot more on mold cleanup.
Given a choice, turning off your air conditioning for a vacation seems like an unnecessary risk, especially considering mold and mildew are a major source of allergies and asthma attacks. However, it does make sense to set the thermostat higher when you go away. You want the system to run enough to pull some of the moisture out of the house. The “right” setting will be different for every house and depend on the weather. In most cases, you will probably be OK if you set the thermostat 4 or 5 degrees higher.
Some people prefer to turn the system off and open windows. Most of the time, this will not lead to big issues. If you go away in the winter, you can save money and energy by turning the heat off, but most people would not think of doing this, since we know it might get cold enough to freeze plumbing and cause problems.
The risk of turning off the air conditioning in the summer probably is not as great as turning off the heat in the winter, but it is still one to think hard about before taking.