With both cooling units failing in my house over the past week, I have learned a lot about heat pumps.

I thought I would share a few things that I have been told. Feel free to correct me if I am wrong!

* Loud electrical buzzing sounds coming from the exterior unit are not normal and should be looked into right away.
* If you have to put both hands right against the vents to see if air is blowing out, and you still have to guess whether or not it is blowing out air - it's not!
* If you use your electronic thermostat to adjust the temperature more than two degrees, you will be activating the emergency heat strips in the wintertime. This is horribly inefficient and be prepared to fork out a ton of cash to cover that cost.
* Heat pumps work most efficiently when they are set at a temperature and left there.
* The cool air blowing out of the vents should be at least twenty degrees less than the outside air temperature.
* It is great to have friends and family who work on HVAC for a living!
* It is probably best to have a thirty-something year old HVAC unit inspected at least once each year.

Any other lessons I need to learn about the AC?