First piece of advice. Don’t ignore your HVAC contractor when it comes to the maintenance of your HVAC system. They are highly trained professionals that have one goal, keeping your system working in top shape. As local small businesses they also want to keep you happy that’s why when it comes to preventative maintenance you should never go on the cheap. Proper HVAC maintenance can save you thousands and cleaning your coils as part of a maintenance program is one way they do that.
Coils are those cool looking things on your outside condenser unit surrounded by very thin aluminum fins. There are also coils on your inside evaporator unit too. These coils hold refrigerant either in it’s cooled state (for cooling) or heated state (after it has done it’s cooling job). In order for your AC system to work properly these coils need to exchange the heat (or cool) efficiently. If they don’t your unit works longer to get the same cooling effect which in turn means more wear and tear and shorter life span of your HVAC system.
As part of an annual or bi-annual maintenance program your HVAC contractor will clean the fins on these coils. The fins get blocked by all sorts of debris. Outside units (condensers) get a lot of gunk build-up from materials like grass clippings, leaves, pollen and other biological matter, while the inside coils (evaporator unit) usually get buildup from micro-organisms, mold and mildew.
How the contractor cleans these fins can be a wide ranging conversation. One thing that is agreed upon though is this. The best way to clean coils is in a fashion opposite to the air flow. For your condenser unit as an example, this means getting inside the unit and cleaning from the back of the coils. There are a variety of ways that this can be done, either with a spray foamer and hose or with a specialized product like the CoilJet from SpeedClean. Using a product like the CoilJet allows your contractor to get in behind the coils with a targeted water/cleaner flow that powers out debris but won’t damage those sensitive fins. A word of caution, if you ever need to go near the condenser or evaporator units, do not touch the fins. They are extremely sensitive and very easy to damage.
Whatever method your contractor employs to clean these fins make sure they aren’t just spraying the outside of the coils. While the coils will appear clean by using water on the outside it actually pushes dirt and debris deeper into the coil “bed”, making them less and less effective.
Get involved with your HVAC contractor and discuss the maintenance that they will be doing. You’ll find them friendly and more than happy to discuss the system with you. Whatever you do though don’t attempt to maintain your HVAC system by yourself. There are plenty of pitfalls to damaging the system or worse yet hurting yourself.
Final note. Don’t forgo your maintenance. You’ll end up paying for it dearly in lost efficiency and broken systems in the end.