Air Conditioning on a HOT Day...

Okay, so it has been a month since my last post. Well, given the temperatures we have been enduring, you are just going to have to cut me some slack. I have been running around all over the Tulsa area trying to help people survive this crazy heat.

In this post I hope to help some of you understand why you may have had trouble keeping your home as comfortable as you would like during these extreme temperatures.

Okay, some of you may have older air conditioning systems that need to be replaced, and I would be glad to help you with that. However, others of you may simply be dealing with the fact that the outdoor temperatures have been higher than what your system was designed to handle. Let me see if I can explain what I mean.

As I have discussed in previous posts, the size of your heating and air conditioning system should have been determined by a heating and cooling load calculation, especially if your system is original to the house. Well, the design temperatures used in your heating and cooling load calculation may be what is causing your system to "underperform" on VERY hot days.

You see, when a load calculation is being prepared for a home in the Tulsa area the system is most commonly designed to be able to provide an inside air temperature between 73 degrees and 75 degrees when it is 98 degrees outside. So, assuming this is how your system was designed, it would not be out of the ordinary for you to experience a small amount of "thermostat creep" as the outdoor temperature rises above 98 degrees.

So why don't we design the system to be able to provide 73 degrees to 75 degrees inside with outside temperatures of 105 degrees?

The simple answer is because that would cause the system to be oversized for your home. In this area we normally only have about 6 to 7 days each year that are over 100 degrees. If your cooling system was designed for temperatures in excess of 100 degrees, it would "short cycle" during the majority of the time when the outside temperatures are below 100 degrees.

What does it mean to "short cycle"?

When a system is said to "short cycle" we are referring to the system running less than 15 minutes before turning off. As with most mechanical items, frequently starting and stopping the cooling system reduces its lifespan significantly. It also does not allow the system to properly dehumidify your home. This leads to the air temperature being cold, while the humidity level is high. The dangerous effect of cold temperatures with high humidity is MOLD GROWTH, and I don't think anyone wants the fuzzy stuff growing in your home.

So, the next time the temperatures rise above 100 degrees don't be worried if your inside temperature starts to rise slightly...unless you have been having trouble with the system before the outdoor temperature inched above 100 degrees.

Again, I strongly recommend having your system professionally maintained, and this will assure that your system is capable of performing at its maximum potential. However, if you are certain your system is operating properly before the temperatures climb into the 100s, don't be overly concerned if it gets a little warmer in your home than you normally keep it.

If you have any questions, or would like to have someone check your system out, I would love to help you. Or, if you know/think your system has given all it has to give, I would be glad to discuss all of your choices for replacing it with a higher efficient system. Just drop me an e-mail, or give me a call, and we can find a time to get together.

Thanks!