Question: “What’s relatively new in the HVAC industry that has many benefits but creates significant downtime that often cancels out the benefits?”  The answer is microchannel heat exchangers.  The efficiency of microchannel heat exchangers can’t be denied but constantly having to call the service technician because of leaks or heat exchanger plugging can get old very quickly.

We all know the benefits of microchannel – lighter weight, smaller heat exchangers, reduced charge, and lower air resistance.   This technology was first used in the automotive and chemical industries and has been a growing part of the HVAC industry for about 15 years.  Many of the larger HVAC manufacturers have publicly stated that even though there are longevity problems with the current designs, they will continue to offer them on their units.  In some instances, you don’t have the ability to select a more standard finned-tube coil design.  In short, they are telling you, the consumer, that you will have to take the drawbacks of this technology whether you like it or not.

Why so many problems?

1. The HVAC unit runs at much higher pressures than the automotive industry.
2. The expansion and contraction of an HVAC heat exchanger are greater than other industries experience.
3. Vibrating parts are very close to microchannel heat exchangers, including condenser fans, motors, and compressors, and some unit designs have significant vibration problems due to the lightweight structural designs that allow vibration to radiate into the condenser.
4. Microchannel is a very tight heat exchanger design and can easily become plugged, because there’s no filter on the entering air side and many applications are not located in clean air environments.
5. The all-aluminum construction has many airborne contaminants that will attack microchannel heat exchangers. We have seen a lot of normal installations at industrial facilities, airports, and labs that have microchannel surface deterioration within the warranty period.

Can I repair these heat exchangers? 

The answer is yes – but not multiple times.  We’ve listed 5 major areas for leak problems, and any or all of them may be in play with your unit.  When you see a leak in a short time period, there’s about a 95% chance more will be appearing down the road.  The average time for the repair process can be up to 6 hours.

As to what might occur “down the road”, gives rise to a question that an owner needs to take into consideration.   Can our business deal with the constant downtime and high expense of these leaks knowing that the leak events will continue to increase?  Let’s say that the existing microchannel heat exchanger is 3 years old, and you have had 10 separate leak events that have turned your business upside down.  Do you replace the coil at your expense knowing that the manufacturer will only provide you with a 90-day warranty?

There is another alternative.   Get rid of the microchannel design and the headaches and expenses that are a part of this design problem.  Southwest Coil can assist you with finned tube design that will meet your unitary performance, and there will not be a change in either the fans or the motors on the condenser.  Each unit design varies, so we would need to make sure we can fit the finned tube coils into the same track on which the microchannel heat exchangers are mounted.  We can identify some of the problems of each system and build the new condenser coils to deal with the application, which may include coating of the coils.

Southwest Coil, as the exclusive representative in the southwest region for USA Coil & Air, has been replacing condenser coil sets for 4+ decades.  Many of these coils have inherent problems that can eventually cause inefficiency and even compressor failures.   We are the experts in condenser coil replacement – take advantage of our knowledge, experience, and commitment to excellence.

Happy Holidays, good health, and prosperity to all our customers!  We appreciate your loyalty over many years.