How to Determine if Your AC System is Running Efficiently

Having a central air conditioning unit is great, but if it is not running efficiently you can be in for major trouble. When the unit is not running efficiently it can spike your energy bills, or worse, can lessen the quality of the air we breathe and affect the health of you and your family. When you live in places with hot climates like, Conroe, TX, Willis, TX, Huntsville, TX or Montgomery, TX, then you need an Ac unit that works effectively and efficiently all the times. Here we will discuss the signs to look for that point to your ac unit not running efficiently as well as a way you can test the efficiency at home and a few basic solves you can try on your own.

Signs Your AC Unit is NOT Running Efficiently

There are a few major signs that your air conditioning unit is not running effectively. If you know what to look for, hopefully, you will be able to catch the problem and fix it or have it fixed before you need to replace the unit. And, if you do need to replace the unit, you can do so before it dies and you have to go without AC in the sweltering Montgomery County, Texas heat! Here are a few big signs your AC is not running efficiently.

  • Your Energy Bill Skyrockets – This probably will be pretty noticeable to you and is simple to check. If you go back to the last few months or to your bills from the same time last year and they are significantly more, you may have an AC unit that is no longer running efficiently.
  • Sounds or Smells That Do Not Belong – An unpleasant smell or louder than usual noise can signal something is wrong with your unit. A squeal or scratching sound may indicate there are parts that need to be replaced. If you smell something burning, it can mean a part is burned out and needs to be replaced. If the smell is moldy or musty you may have mold in your unit or ducts and that needs to be fixed as soon as possible so as not to hurt your health.
  • Air Issues – Maybe the most self-explanatory sign of an inefficiently running AC unit is if the air that is coming out of your vents is not cool. You also may notice that the air coming out of the vents is weak and that can spell problems too.
  • New or Excess Moisture – An AC unit that is running efficiently should not have moisture leaking or pooling in places, especially if you have never seen moisture in that spot before. If you see unexpected moisture, be careful. While it could just be water (still a possible sign of a problem), it could also be refrigerant which can be very dangerous.

The Thermometer Test

Even if you do not have major, tell-tale signs like the ones listed above, it is still possible that your AC unit is not operating at peak efficiency. If this is the case, it is costing you money. There is a simple test you can perform by yourself, at home, to determine if your unit is performing as it should be. Follow these few simple steps to find out if there is, in fact, a problem with your AC unit.

  • On a warm day, set your thermostat to a temperature that is well below the outside temperature.
  • Once the AC unit has been running for at least 10 – 15 minutes, you can perform the “Thermometer Test”
  • Take a thermometer and measure the temperature that is coming out of an air duct.
  • Then, take the temperature of the air that is going in through the return air duct.
  • Once you have these two temperatures, subtract the cool air temperature from the warmer air temperature to get you Thermometer Test results.

The number you come up with from this test should be between 14 and 20 degrees Fahrenheit. If it is bigger or smaller than these numbers, you probably have a problem. If the number is lower than 14 you could be low on refrigerant in the system or have a leak somewhere. If your number is higher than 20 there could be a blockage in the system or a clogged air filter.

Basic Solves

No matter what makes you think you are experiencing a poorly running AC unit, there are a few basic things you can do on your own to help your unit run at peak efficiency. If doing these things does not clear up your issue, it is probably time to call a professional. Also, you should note that if your problem is one of the things that can cause serious health problems, it is DEFINITELY time to call a professional. With issues that do not indicate danger, here are a few things you can do.

  • Clean Your Outside Unit – Since the driver of your AC unit is outdoors, if there is a problem, check to make sure the unit is not damaged and there is nothing blocking its vents. It is also a good idea to turn the unit off and spray it down with a hose once or twice a year to keep it clean.
  • Check Your Ductwork – Leaks in your ductwork is a big cause of inefficient AC units. If you see that air is escaping you may be able to fix a small leak with a little duct tape or you may have to replace the section. Also remember, the better insulated your ductwork is, the longer it should last.
  • Change Your Air Filters – Especially in places like Montgomery, TX, Huntsville, TX, Conroe, TX and Willis, TX, your AC unit will be operating A LOT so you should change your filters regularly. Most HVAC specialists recommend every 3 months or so but it differs from situation to situation.


No one wants an inefficient AC unit because it can hurt your health and your bottom line. If you suspect that your unit is not running efficiently you can try some of these solves or call a professional like the ones at T.C.S. A/C & Heating in Willis, TX. They will be able to make sure your AC unit is running at peak performance.