What Is The 20 Degree Rule?

With the hotter than average temperatures we’ve been experiencing (and that are in the forecast), your air conditioner has been running more than usual, which can mean higher than usual utility costs.

As we’ve said before, NOTHING impacts your utility costs more than the weather, particularly the outside air temperature.

You may have heard someone mention “the 20 degree rule” when it comes to your air conditioning unit. But what does that mean?

Simply put, it means you should never set your thermostat for a temperature more than 20 degrees cooler than the outside air. Why not? 

Most air conditioning systems can only handle a 20-degree difference between the outside and inside air temperatures. If it’s 80 degrees outside and your thermostat is set to 70, your unit should have no problem. But if it’s over 90 degrees at that same setting, your unit will have to run almost non-stop to get your inside air temperature to 70 (and it still might not make it).

And a constantly running air conditioner will cause your utility costs to skyrocket. 

Experts recommend setting your thermostat to 78 in the summer. Yes, that’s higher than you might expect, and if your health or other circumstances make that difficult, then you shouldn’t set it that high.

But keep this in mind: temperatures close to 100 are in the forecast this week, and the lower the setting on your air conditioner, the more it will run, and the more it will cost you. If possible, set your thermostat at the higher setting and help it out by closing drapes, running ceiling fans (counterclockwise) and other fans to circulate air, and not running heat producing appliances during the heat of the day.