Jim Wheeler 2013-11-09 11:53:34
Protect yourself A good friend of mine called the other day and told me: “I had my regular A/C spring tune-up last week and this week it stopped working. So I called my A/C guy and now he says I need to change out the whole thing!” He, of course, wanted my opinion. And my opinion is that most A/C service companies in our area are doing more harm than good with their tune-ups because they simply don’t have or use the correct tools. And what they do (other than change a fi lter) is probably wrong. That’s why it irritates me that most equipment manufacturers say they require annual servicing before they will honor a warranty. What does a typical “system maintenance” in our area usually entail? Believe me, I know! There may be an outdoor coil cleaning using a lye-based “brightener” (that reduces the coil life and effi ciency by several years), a fi lter change, a visual inspection and the addition of a little extra refrigerant “just to top the system off,” which may thereafter reduce operating effi ciency and shorten compressor life. Oh yes, they also may attempt to oil the indoor and outdoor fan motors, which have no oil access since they are sealed. Hopefully, the service companies will add some drain tablets to the evaporator, but that’s it. It’s mostly an overpriced sales call. What should they be doing? Cleaning the outdoor coil with plain water or with a vacuum; Changing the fi lter; Adding drain tabs; Checking the refrigerant charge with a thermometer (only) and with an electronic sight glass (to check for air in the system); "Megging” and recording the resistance to ground on the compressor and fan motors (checking for deterioration and moisture); Checking the static pressure drop across the air handler or furnace and across the evaporator coil to make sure there is enough (rated) airfl ow; Doing a visual inspection; Physically cleaning the cabinets to prevent rust and to make them look good; and Checking all fans to make sure they are clean, in good shape and turn freely. Shouldn’t they clean the evaporator coil? Not with a foaming cleaner. If that is required, it will show up when the tech takes the static pressure readings and will require removal of the whole coil and a pressure washing with a good noncaustic degreaser. That’s the problem. I know proper and nondamaging preventive maintenance on A/C units and heat pumps is hard to fi nd in our area and it likely is in your area as well. I don’t think I have ever read an article or book or attended a class where doing the job properly is ever stressed. And the person who often is sent out to do such jobs is frequently the least qualifi ed. What am I suggesting? We need more training! If your company does it or if you’re working with a local trade school that provides it, make sure the proper methods are what students and technicians are being taught. Look for future articles on this subject where I will discuss what tools are required to do a good A/C preventive maintenance and how these tools (which you sell) must be used. What the friend I mentioned above experienced should never happen. The idea behind a tune-up is to prevent failures, not create them.
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