This is a little tutorial on air conditioning. There’s no way I can possibly teach you everything you need to know as a diy’er when it comes to HVAC but I can try to explain some of the basics when it comes to air conditioning. I can give you an idea of how your air conditioner works so in the event that you have to call a qualified HVAC technician like -you’ll know how to speak to them and get the right kind of help. You’ll be able to understand the goobly gob that the technician might try to throw at you when trying to explain to you what your AC problem might be.
Even though the only thing you might care about is to get your AC system up and running again because you are hot,there’s some things you should know. In the HVAC business there’s a little known secret that sometimes ignorance is not bliss. Sometimes you are getting charged for something that you should not be getting charged for. Sometimes you are getting hoodwinked on a part that is getting changed out that never usually gets changed out. Sometimes it’s a very simple part but because you have a technician making a service call the company wants to and needs to make hundreds of dollars on that call in order to stay profitable. They don’t want to just make $50-$100 on the call. Some parts might only be $15-$20 and even with a 100% markup on the part,it’s still not a feasible service call for the company. They would prefer to make $200-$500 or more on your service call.
This is why it is important to understand the basics on how your system works. By the way,always ask for the parts that get changed out. Just like you would with an auto repair,you want to see the parts that are getting changed out when you have your service done. That way,you’ll have a better understanding of what went wrong on your system.
So,here are a few basics on how your air conditioning and cooling system works.
Older AC systems work off of R22. But now we have different types of Freon. The Freon works in a circular type fashion. You have coils on your outside condensing unit and you have coils on the inside where your heat exchanger is located. Inside of the coils is all of your Freon. So,you have a low side and you have a high side. The high side eventually goes into your inside coil into a capillary tube and it gets very,very hot. It’s also under a lot of pressure. When the Freon expands out finally after entering the capillary tube and coming out then it becomes cold. When it’s cold it actually goes through your coil on the inside and you have a blower and it blows against the coils and then through the duct work to ultimately cool off your house. The Freon comes back around again in a loop,entering into the system again to continue that cycle.
Deep inside the outside unit is a compressor. It compresses your Freon to where it can be used for the cooling cycle. The compressor is like the heart of the system. Sometimes your unit might become low on Freon. If that’s the case,the technician simply needs to charge it back up.
Next let’s get into the electrical side of the AC unit. The 240 amp circuit hooks into the unit and leads to a capacitor. The capacitor is what gives the unit that little kick it needs to really get started. It’s a little bit like a starter motor on your car. The capacitor is tied into both your fan and your compressor. Along with the capacitor,you’ll find the low voltage wire which leads into your home to the thermostat. This thermostat and low voltage wire leads to the contactor and tells it what to do whether that means to turn on or turn off. It’s that simple. The real cost to change out a contactor is about $50. Of course that doesn’t include the service charge. The capacitor is about the same cost. The other things that can go bad are your compressor and your fan.
If the thermostat goes bad,that’s about $30 – $40 dollars to replace. If the fan motor for a typical condenser goes bad that can cost between $75 – $150 for the part. If the compressor goes bad,you are screwed. They are too costly to fix. Other costs to consider for your AC repair are the service call charge and labor.
Another tip coming from - is to beware of companies that require you to change out your inside coil just because your condenser goes bad. It’s a sales gimmick that they use to scare you into saying that they won’t warranty their work if it’s not done.
There you have it! Now you are armed with some knowledge that will keep your next HVAC service call from getting outrageously expensive.