Author Topic: Cleaning out the house AC condenser and Capacitor  (Read 238 times)

Offline goodfellow

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Cleaning out the house AC condenser and Capacitor
« on: May 07, 2018, 02:47:47 PM »
Thanks to our friend Bonneyman and his helpful HVAC hints and insights I decided to tackle the AC system in my house this weekend. I sprayed the evaporator coils with a proper cleaner that is approved for this type of service, and also cleaned out the water tray of rust and corrosion gunk. Finally I blew out the condensate drain pipe with some compressed air to make it flow -- I was surprised at the amount of blockage that was in that pipe.

Today I worked on the outside condenser unit. It's definitely in need of attention -- full of leaves and dirt and rusting. It functions well, but I let it go for three years without a good cleaning.



The first thing I did was to pop the fan off the top of the condenser coils and strip the rust and old powder coat. It took a few hours with a wire wheel , but it was eventually clean and ready for three coats of gray implement paint. Unhooking the motor is no big deal -- three wires -- two to the capacitor and one to the contactor.

NOTE -- if you do this yourself, don't forget to kill the power to the outside AC unit and to short out the capacitor before working on it.



Next I vacuumed up the debris on the inside of the unit and opened up the drain holes. I blew compressed air from the inside of the condenser coils to clean the debris that had lodged in there for several years, and finally hosed it down with some cleaner to get the remaining gunk.

For good measure I cleaned the contacator with CRC electrical contact cleaner and I replaced the capacitor because the old one was looking a little rough -- corrosion at the terminal has taken its toll, and it had been in there for quite a few years. The HVAC techs will charge an arm and a leg for these things, mine was around $30/shipped several years ago, and I just ordered a new replacement for $20 shipped. I try to keep a spare on hand in case the thing blows out in high summer heat.



Everything bundled back up and the fan is ready to be put back. Took about four hours to do the whole job.





Ready for the season --

clean on the inside .....



and the outside --



It's not a tough job, and most of us can do this work every few years to keep these things working properly. 



« Last Edit: May 07, 2018, 03:20:54 PM by goodfellow »

Offline OldnSlo

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #1 on: May 07, 2018, 06:02:51 PM »
Are you going to keep that cap nicely tucked away in the box? Seems a bit of a moisture magnet to me.

Offline goodfellow

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #2 on: May 07, 2018, 06:49:47 PM »
Are you going to keep that cap nicely tucked away in the box? Seems a bit of a moisture magnet to me.

It's dry -- and the boxes have always come out in good shape. I keep the boxes in there to remind me what the specs of the caps are in case I forget -- or misplace the info.

Offline bonneyman

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #3 on: May 07, 2018, 07:04:36 PM »
Glad my advice proved to be helpful. Nice repaint job on that condenser motor screen!  thumbsup2

For future reference, help keep the condensate P-trap and line clear by using my homebrew drain cleaner. Mix up a solution of 3 parts Pine-Sol to 1 part industrial strength ammonia. (I once found a bottle of pre-made such cleaner, and it worked so well I made up my own formula after it ran out). Pour a cup of this solution down the drain once a month during the humid season (or when you change your filter).
I have a batch mixed up that's one full bottle of Pine-Sol (1.25 quarts) with a little less than 1/2 quart of ammonia. I add a few drops of green food coloring into the mix so the wife doesn't confuse it with the regular ammonia for cleaning and such. In the three years I've been doing it, my drain lines and condensate pump have stayed surprisingly clean.

P.S. Ha! I found the pics I have of that original chemical. Perhaps you could find it at a yard sale or something?

Offline stokester

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #4 on: May 07, 2018, 08:24:59 PM »
Thanks for sharing!   beerdude
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Offline Muddy

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #5 on: May 07, 2018, 10:16:29 PM »
Wish we had central air

Sent from the twisted mind of the Mudman.

"And on the 8th day, God looked down on his planned paradise and said, "I need a caretaker." So God made a farmer."

Offline bonneyman

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #6 on: May 10, 2018, 11:57:49 PM »
Cleaning the A/C coils is so freaking important. Not only does the unit run "easier" as the air can flow through the fins better (and the compressor runs less hard, drawing fewer amps, meaning it costs less to operate) but the heat transfer from the freon in the tubes to the fins into the air being exhausted is higher. Thus, the unit removes heat quicker, meaning the temp drops in the house faster and the thermostat satisfies and shuts the unit off. Which also cuts the electric bill. The unit runs less, and -when it does run - it is working less hard.

Any dirt or debris that hinders heat transfer through the coil translates to less efficiency, longer run times, and more wear and tear on the system. Less heat is leaving the coil, so more heat builds up in the coil, raising the head pressure and increasing the workload on the compressor.  It really does pay to keep the coil clean or have a technician come out and do it.

Offline brslk

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #7 on: May 11, 2018, 03:05:44 AM »
How often should this be done?  Our AC unit is about 4 years old and I've never even looked at it.  We don't cover it in winter and probably should. 
Is there a basic list of maintenance that should be done once a year or on a certain schedule?

Good job Ray,  looks like new.  Congrats on not zapping yourself with the capacitor! lol 
I'm just a guy in a garage with some tools...

Bruce.

Offline goodfellow

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #8 on: May 11, 2018, 10:15:38 AM »
How often should this be done?  Our AC unit is about 4 years old and I've never even looked at it.  We don't cover it in winter and probably should. 
Is there a basic list of maintenance that should be done once a year or on a certain schedule?

Good job Ray,  looks like new.  Congrats on not zapping yourself with the capacitor! lol 

Thanks Bruce!   ;)  BM's posts reminded me that this service hadn't been done in years. The outside unit was sitting close to a bush and in the fall the leaves dropped right through there. I cut the bush last year and the amount of debris in the unit was significant. I will do this service every two years from now on.

The evaporator was the BIG mess -- but only on the underside. From the outside it looked clean, but when I took the front cover off and looked underneath, the dust and dirt buildup was significant. It had not been cleaned on the inside as far back as I can remember. We've owned the place since 2005.

We used to do yearly inspections with the HVAC company, but they ONLY sprayed the outside of the evaporator with cleaner. They have never taken off the cover (because it's difficult) and cleaned the inside -- that's where the dirt, hair, and fuzz accumulates. I think the evaporator is where most of problems start (BM correct me on this) because it presents such an access problem.
« Last Edit: May 11, 2018, 10:18:52 AM by goodfellow »

Offline bonneyman

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #9 on: May 11, 2018, 12:46:19 PM »
How often should this be done?  Our AC unit is about 4 years old and I've never even looked at it.  We don't cover it in winter and probably should. 
Is there a basic list of maintenance that should be done once a year or on a certain schedule?

Good job Ray,  looks like new.  Congrats on not zapping yourself with the capacitor! lol

My service policy is:
1) Clean condensor coil once a year in the spring before you start it up for the summer.
They're designed to be out in the sun, dirt, rain, etc so I'm not too concerned if there's some leaves or debris in the bottom. If it's thicker than 4" deep then I pull the top off and clean it out.

2) Clean the evaporator coil (typically inside) when it needs it.
This is very subjective. If you replace the filter monthly with a quality pleated filter - sprayed with Endust - and it's got foam tape around the edges so dirty air can't slip past a clogged filter - you can probably go 5 years without a cleaning. Being the evap coil is usually in a sealed, taped cabinet on top of a furnace or air handler it's a real pain to get to. Takes alot of time and gets $$$. Plus on newer coils the damn fins and tubes are so thin that jostling the coil around trying to get access to the inlet can break something. All in all it's one of the reasons I harp on people changing their filters more than almost anything else.
If I go to a customers house that I haven't been to before, I look at the gauges real closely and measure the superheat and subcooling. Those readings will indicate if the evap coil is substantially restricted. Then I go and tell the customer what they might be in for. But I hate doing that to new customers, because being my first time out there and I drop a $400 or more estimate to "clean" something that to their mind has been working fine.

It's really hard to play phone doctor on an AC, Bruce. You really should have a reputable technician come out and inspect. But I'll go out on a limb and give you an industry "rule of thumb" hidex

Make sure your filter is clean/new.
Turn the AC on, and run it for 10-15 minutes. I'm assuming the outdoor temp is at least 90-95.
Go outside to the condensing unit (where the compressor is). You'll see two copper lines coming out of it. Grab one at a time. The small one should be warm to the touch but not hot (say 90 deg or so), the large tube should be cold but not frosty (say around 40 deg or so). If it passes these tests and you're getting good amounts of air out of your inside vents, you're probably OK.
« Last Edit: May 11, 2018, 12:49:36 PM by bonneyman »

Offline goodfellow

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Re: Cleaning out the house AC condenser and Capacitor
« Reply #10 on: May 11, 2018, 01:26:09 PM »
Thanks for the great tips BM -- I learned a lot just browsing your posts.   thumbsup2

I will definitely keep them in mind when purchasing a new unit.

The Garage Gazette

Re: Cleaning out the house AC condenser and Capacitor
« Reply #10 on: May 11, 2018, 01:26:09 PM »