Does heat index affect air conditioner performance?

Question

I've got mixed responses to this question. If the actual temperature is say 99 degrees and the heat index is near 110 degrees, does that affect the performance of an air conditioner, or would the A/C perform the same in this senario as it would if the heat index was also 99 degrees?

Answer 1

Your A/C will be removing more moisture from the air at a higher heat indices rating.  Air holds heat more readily when moist.. so the A/C will be working harder..  longer, to cool your space.  

Answer 2

Yes, it is about the humidity and yes the more humidity the harder your a/c has to work until it lowers the humidity in the house.

Besides the water in the air (in the house) being more mass that requires cooling, when the moisture is condensed it releases heat. Trying to cool more humid air can lower the efficiency of the a/c as much as 15%.

The good news is that the a/c will lower the humidity in the house when working so then it only needs to remove the moisture that may come in to the house.

Where you would likely notice it the most is if you turned it off during the day. Then when you turned it on, the more humid the air is in the house the longer it would take until the air started to cool down because it will be working to remove that moisture first.

If it is on all the time, you likely won't notice it, and it will only affect the a/c a little because you are not trying to cool the humid outside air unless the house is real drafty.

Good Luck.        

Answer 3

its all about the moisture content in the air