It’s easy to forget about your heat pump when temps climb into the 70s, but early summer is an important time to show your heat pump’s compressor a bit of love! We suspect that your heat exchanger fins are gunking up!
You may have noticed ‘willow snow’ floating around our air recently. Willow trees across southeast are shedding their seeds, sending the tiny reproductive packets on their way with the aid of what I like to call willow snow, that bit of cottony fluff that catches any bit of wind and takes the seeds to their prospective new homes. While this is an impressive and ingenious seed dispersal method, these seeds and associated fluff are great at gumming up our outdoor heat pump compressors. And, once the willows are through, fireweed seeds will fly close behind!
As your heat pump compressor pulls air across its heat exchanging fins, willow and fireweed fluff, along with grass, flies, and any other air-transported material, will accumulate on the fins. This material works to block both air transport and the heat exchanging process, decreasing the unit’s efficiency. In short, operating costs go up and performance, i.e. the ability to heat or cool, goes down.
My heat pump compressor is fairly well removed from trees and plants, yet the middle two photos above show its condition this morning. It’s not horrible, like the internet-grabbed image on the far left, but it could be better and it will just worsen as summer progresses. It’s time for a cleaning!
Some local heat pump contractors offer an annual maintenance service, a process well worth the small fee, considering what you have invested in your heat pump. Call around to see who is available to do this important maintenance work. A few times each summer I take care of the easiest part of the cleaning process myself. If you choose to clean the fins on your own, BE CAREFUL! The heat exchanger fins are extremely fragile and can bend easily. While bent fins can be straightened, a special ‘comb’ is needed and a contractor may be best suited to take care of this detail.
I use a vacuum cleaner with a long hose and a very soft brush attachment. If you look closely at the fins, you’ll see that they run vertically, top to bottom. If you work side to side, you will bend the fins. Very slowly, I run the brush from the bottom to the top, pressing very lightly to draw up as much material as I can. Working gently may mean that a few passes are needed. The results won’t be perfect, but the fins should be much cleaner than when you started. The left side of the compressor fin array is blocked by a screen of sorts, attached with a few screws. In the images above, this is the third image from left. I take this off and work the vacuum gently up or down these fins, putting the screen back in place when done.
And that’s it! There are other parts of the compressor that should be cleaned as well, but if you just want to get rid of the bulk of the mess, carefully using a vacuum and soft brush attachment can do the trick.