I cleaned the "A coil or evaporator coil" on my furnace and, boy, did it make a difference.

[Hassin Bin Sober]

I thought I would pass along my experience.

This is a fairly easy project for a moderately skilled do-it-yourself-er.

I consider myself a fairly skilled carpenter but I have never done much with HVAC. I've always paid to have my system checked/repaired - I guess that's what pisses me off the most. I've had people in to do the "routine cleaning" every year but no one ever mentioned the A coil so I didn't think much about it....

Until last year when my neighbor had hers replaced. We use the same service and the HVAC company refused to clean hers when the coil was diagnosed as very dirty. The airflow had become too restricted and caused over-temp shut-downs last winter resulting in the service call. Their policy is to replace, not repair/clean. I guess that explains why mine was never cleaned.

This got me to thinkin' about mine. So I figured I would tackle mine this summer. And I"m glad I did.

The A coil/evaporator coil is located (in my furnace) above the furnace in the plenum. See below:



The process was fairly simple.

I used my Dremel wheel-cutter to cut an access hole in the side of the plenum. I cut one "test" hole in the side to see how the coil was oriented. The second hole was cut in the right place so I was able to get my hand all the way in under the "A" portion.

I pulled 15 years worth of gunk from the coil. It was like a layer of felt on the coils. Yikes. Now my AC blows like a wind tunnel compared to the flow I had before. Also, the heat will blow better because, even in winter, the warm air blows over the coil when the coil is not in use.

The hole was patched back up with a piece of sheet metal and some self tapping screws purchased at Home Depot. The seams were taped up with the foil backed tape from HD also - as was the rest of the furnace. Don't use "duct tape" - it's crap. I re-taped the entire furnace seams. That made a difference also (I assume). The closet where the furnace is kept is no longer ice cold.




Note: The evaporator coil in the furnace is sometimes referred to as an "A coil" due to its A shape - some are slant coils on 45 degree angle. Your may vary.

Note: sheet metal is sharp and can easily cut you. Wear gloves and eye protection when handling or cutting.

Note: Be gentle on the coil "fins" so you don't bend them and further restrict airflow. Come to find out, there is a commercially available coil cleaner that I will be looking for for a more extensive cleaning now that I have fairly easy access to the coil.

[Stinky The Clown]

1. The HVAC company we use put in a removable access panel when they installed our new system.

They replaced all the ductwork from above the A-coil to the furnace. The replacement has this access panel with screws and a gasket. Take out the screws and you get to the A-coil.

By the way, they clean the A-coil as part of their standard annual service.

[Hassin Bin Sober]

2. "part of their standard annual service"

Smart outfit. That's why they left an access panel, I suppose. Well now I have one too.

It's funny. You talk to different people and you get different answers.

My partner's dad is the person who kinda walked me through the process when we were considering cleaning the neighbor's (she bought a new system). He's a retired commercial pilot but he dabbled in HVAC with one of his pilot buddies. He says they cleaned them all the time by either cutting the access hole... or sometimes they would remove the unit all together and hose the coils off.

I talked to my ACE hardware guy and he looked at me like I had a screw loose. He says you should NEVER have to clean the coil if the furnace is properly filtered. But that doesn't make sense considering 5, 10, or 15 years is a long time for residual junk to get past the filter.

You don't realize how clogged something is till you clean it out. Last year, I was at my wits end. We couldn't keep the condo below 80 degrees on hot days. We resorted to using a small window unit in the bedroom to sleep. Now we are living it up at 76,77 in the day and 73 at night - and the system actually shuts off.

Other things we have done is blown in cellulose in the attic/crawl-space thanks to rebates from the gas company. Reflective coating applied to our west facing front windows. And a temporary cover for the skylight- it's landscape fabric bungeed to the skylight until I find a suitable commercial product..

This is a good year for conservation.

[sammytko]

3. We had ours thoroughly cleaned this summer and it's only 2 years old - filthy!

We change the filters becausevwe live in an old drafty house and it seems we pull in all kinds of lint and fur balls from somewhere. Oh yeah, we have 5 dogs and 4 cats! He did find that the installation crew left the manual inside and it was blocking air flow. It would freeze up because it was working too hard to cool. It took him a couple of hours to check it out.

I have it checked winter and summer.