AC Maintenance

[MarkSLSmith]

Folks, 

It is that time of year again, ie time to maintain the air conditioner.  In my case the AC is Trane.

My question is about washing the condenser coils.  The coils have the frilly heat transfer stuff (not sure what to call it) attached; this definitely rules out any high pressure/high flow cleaning media, because it would be bad to flatten the frilly stuff.  Whenever the AC guys clean them, they just aim a garden hose at low flow rates at the coils.  They often don't even remove the grill.  

Whenever I do it, I at least remove the grill.  But so far, I'm just copying the AC guys' technique.  I feel unsatisfied every time I do it.  

What do others do?  Anybody have better procedures? 

Thanks,
Mark

[Admiral]

Funny, just had mine done this morning; now, its a two year old installation, replacing contractor grade Trane with a high end Lennox so I got maintenance free for 4 years as part of the deal; but the tech just removed a side panel and used my garden hose to flush out the fins. I'd also be concerned that a powerwasher might have too much power for that job.

[TDKPE]

The coils have the frilly heat transfer stuff (not sure what to call it) attached . . .

Ah, yes - the infamous Spine Fin coils.  I solved my cottonwood problem by replacing the whole thing.  But before that, I wrapped a window screen around the unit for the month of June.  

I did find an article recommending cleaning cottonwood with a torch, then a wash.  But it's just something I found, not something I'm recommending, especially since I don't really know much about cleaning these coils other than washing from the inside out.  And eventually replacing with a new system.  Trane doesn't even use that style any more.  
 

https://comfortmattershtg.blogspot.com/2...ioner.html

[Robert Adams]

Ah, yes - the infamous Spine Fin coils.  I solved my cottonwood problem by replacing the whole thing.  But before that, I wrapped a window screen around the unit for the month of June.  

I did find an article recommending cleaning cottonwood with a torch, then a wash.  But it's just something I found, not something I'm recommending, especially since I don't really know much about cleaning these coils other than washing from the inside out.  And eventually replacing with a new system.  Trane doesn't even use that style any more.  
 

https://comfortmattershtg.blogspot.com/2...ioner.html

            I haven't seen one of those coils in 20 years. Cool looking but they need a hepa filter to keep them clean... There should be a 5K bounty on cottonwood trees. Nothing but messy and they drop branches. They make it look like winter in march-april when they spread their pollen.
 
            For those buying new units stay away from the Payne units. They are utter garbage builder grade crap. The nosiest compressors I have ever heard and small double stacked condenser coils. The guy that built the house next door to us had one put in and I am probably going to buy a compressor blanket, rubber pads and go put them on for the neighbor but really for me when I am outside. They are noisy when running and when the shut off they sound like you dropped it off the back of a truck. I have never seen a quiet one.

[blackhat]

This HVAC guy does what your HVAC guy does essentially.  I'll give them a spray with some soapy water or spray cleaner and let it soak a bit before hosing it out.
Those coils are horrid.

[daddo]

Spine fin coil.

As far back when the brand was GE, the book described washing the outdoor spine fin coil with soap and an open hose only.

I use dawn soap and a open hose with my thumb over the end to create a little more velocity. Wash it right through the grill. Removing the grill won't do any more good. Some models that don't allow easy access to the coil, the fan top can be removed and then you can rinse it from the inside out.

I often run across cottonwood covered coils. I use the torch to burn it off then wash it out. Be very careful, the coil is aluminum and will melt if you get it too hot- keep the flame moving! There are also sensors in some coils- I suggest getting this pro done.

There is a company advertising that washing the condenser with just a hose will not get it clean. They are whether ignorant or lying- somewhat.
They claim to have a machine (Pressure hot water washer type) that will only get it clean. If the coil is badly caked with a certain brick dust/dirt or flour, it can be hard to clean. A greasy coil is difficult to clean, but these are found on restaurants mostly where grease fans are running.
Double coils need to be separated sometimes for cleaning.
I have never needed hot water or pressure for cleaning a residential condenser, except as I mentioned, a restaurant. Beware that the psi they use does not damage the coils fins.
 I never use acid or alkaline cleaners on condensers (Except certain greasy commercial systems) and very rarely on evaporators. Each can or will cause corrosion if not completely removed.

I guess if I spent a couple of thousand or more on a sprayer, I would try to scare people into thinking they need to spend a hundred or two having me super clean their condenser. Or not!

It is known that a Trane or American Standard spine fin coil can be blocked as much as 30% and still function properly. One of Tranes/AS bragging facts.

[MarkSLSmith]

The good news for me is that cottonwood isn't really an issue.  My neighbor used to burn the cotton out of his unit, before his trees bit the dust about 20 yrs ago.  

I just want to make sure the coils are clean.  I hadn't tried the dishwashing detergent idea, so that hopefully will be an improvement.

Thanks,
Mark

[Robert Adams]

The good news for me is that cottonwood isn't really an issue.  My neighbor used to burn the cotton out of his unit, before his trees bit the dust about 20 yrs ago.  

I just want to make sure the coils are clean.  I hadn't tried the dishwashing detergent idea, so that hopefully will be an improvement.

Thanks,
Mark

           The very best cleaner for condenser coils is the red soap for Hobart commercial dishwashers but don't do it... It is very very good cleaner but it is very acidic and they even have a neutralizer that they use in the dishwashers during their cycle. 
          But if you do run across some of it grab it and it males great driveway cleaner for getting oil and grease off.

[farmerj111]

I've always used a foaming cleaner that I picked up at the appliance parts store.  An AC tech recommended it to me; you just spray on with a garden sprayer and hose off.  They also sell a few versions of this type at home centers.

https://www.homedepot.com/p/AC-Safe-Air-.../206740351

[MT Woodworker]

Spammer .........