A Goodman 3-Ton Air Conditioning Unit

#1. A professional air conditioning service tech should always remove the top off of your air conditioning unit. This is the top part of the air conditioning unit where the fan blades and fan motor are attached to a perforated steel top. For air conditioning units located on the roof, the hvac service tech should always clean the air conditioning coil with high pressure nitrogen. Nitrogen is non-flammable and a high pressure gas that cleans air conditioning coils well. For air conditioning units that are located on the ground, they will probably use a water hose. In my personal opinion, each one has a little bit of a pro and con, but both methods work well.

The next most important aspect to air conditioning maintenance and repair is the refrigerant charge, super heat, sub cooling and temperature difference. A typical temperature difference in a residential air conditioning system should be around 20 degrees farenheit. To get the TD you must measure the temperature at the return air duct and the supply air duct. That air conditioning  temperature difference should be around 18 to 20 degrees, typically. The other part of that equation is the refrigerant charge.

The TD has a lot to do with the refrigerant charge in your air conditioner.  If your air conditioner is low on refrigerant, the TD will be higher, let’s say around 25 degrees. If it’s overcharged it will be more like 15 to 17 degrees farenheit. There is one more thing that affects the TD and it’s the air flow.

Air flow in a central air conditioning system is critical. If your air filter is clogged or your AC coil i plugged and air is having a hard time flowing through the air conditioning system this will throw the TD off as well. Typically, the way you can tell if there is an air flow problem in your air conditioning system is through your pressure guages. Typically you will see an abnormally low, low pressure side reading of around 66 degrees or so. You see this reading because there is not enough air flow to boil off all that refrigerant going through the air conditioning coil because the air filter or a-coil is clogged.

This may be getting a bit on the technical side but whole point here is that there’s more to air conditioning maintenance than just price. As of late, there are so many companies quoting such low prices for air conditioning clean and checks I don’t understand how they are making any money. Some companies are charging $59 for a clean and check. It costs $30 in gas and wages just to make it to a customers location. Those companies must be charging for unnecessary or unethical air conditioning repairs or service that is not needed. I know as an hvac business owner that these guys will not be in business very long or are a fly by night company anyway that won’t be around to back up their work. Or they are just taking people for unnecessary repair. The whole point of this post on air conditioning maintenance is so you can hopefully take away a sense of what a professional air conditioning company does compared to some kid working out of his garage would do and charge. Remember, you get what you pay for. If you ever have any questions about anything related to air conditioning please give us a call and we would be happy to answer any questions you may have, free of charge. Thanks Chicagoland and have a cool summer!