Controversial article claims no benefit to cleaning AC condenser; What say ye?

Motorapido

What do the pros think of this article, which states that cleaning AC condensers is not only unnecessary, but also that some dirty condensers perform worse after you clean them. The article doesn't present the type of lab testing results of this hypothesis that I would need to be thoroughly convinced. Has anybody seen compelling lab data on this topic? Here's the article https://news.yahoo.com/skip-chore-cleaning-air-conditioner-140405094.html

pecmsg

Ill continue to wash mine once or twice a year!

Motorapido

pecmsg said:

Ill continue to wash mine once or twice a year!

Yeah, it's not like it takes more than 15 minutes to do, and in the process you get the bonus opportunity to see if a critter built a nest inside the enclosure and other visual inspections. I'd rather end war or solve human suffering than eliminate the minuscule task of cleaning condensers. But I'm still curious to know if this hypothesis has been legitimately tested.

Jamie Hall

Oh for heaven's sake. Other than the minor detail that there were no data presented -- only a few conclusions on what may have been a very limited sample (academic rigour was either absent in the study, or not reported) the difference reported are probably not statistically significant -- nor do I see much mention of controlling for other factors.

It's always helpful in studies of this sort to consider the absurd boundaries of the situation -- in this case, a brand new, thoroughly cleaned coil (they aren't, out of the factory -- rolling oils if nothing else on them) vs. a completely clogged with dirt coil.

Um... right.

GGross

I'm not sold. They tested a few dirty A/C before and after cleaning, how many units has Carrier tested? Lennox? Amana? I am guessing the manufacturers have tested many more units than what was done in the study. They are also only testing unit efficiency, no discussions of any other issues that can be fixed or prevented from simply cleaning up your equipment once a year. It is also kind of strange that they still come to the conclusion that you should probably clean your condenser even though the basis of the study is claiming you should not. Seems like just some Yahoo news clickbait to make people feel better about procrastinating on maintenance.

Matt_67

I’ve personally never cleaned a condenser and had the head pressure go up, so I’m skeptical….

DJD775

Just passing along the link to the actual paper:
https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1142&context=archengfacpub

Tinman

I don’t need to read it to know it’s BS. Heat transfer is a simple concept. 

mattmia2

Keeping the debris out of it so it doesn't hold water and start rust is by far the most important part of cleaning.

JUGHNE

I did a quick read of the actual paper.

IIUC, they passed water thru the coil with air flow thru only one side of a coil.
Used water as the heat transfer medium inside the coil.

This seems a far cry from a hot gas condensing into a liquid with various states of phase change along its journey to the liquid port.

Everyone in HVAC, at some time or other, has seen every component within the standard AC being toasted from lack of cond air flow.

One HO could not believe the lattice work he put around his AC for aesthetics made any difference.
As he saw the head pressure rise by 20 PSI (R-22) when it was re-installed, he realized it was cutting down on cooling efficiency.
(This was the lattice that a cat could fit thru.)

The word/title of "engineer" appears several times in these papers.....this is perhaps what often gives a lack of creditably to the profession.

109A_5

Communications site next to a Quarry.

After a bunch of years of initial service the redundant wall mount A/C units would not cool the site. It was a small room with just about everything in it making heat. Condensers 'looked' fine except if you try to get light through them you could not. Turns out they were almost totally plugged up with Quarry dust and could not dissipate the heat properly. A good cleaning with compressed air and / or water (neither normally on site) returned the A/C to normal operation. Subsequently this cleaning needs to be done at least every two years to keep things happy !!!

ChrisJ

I have a 16 SEER unit, copper tube with aluminum fins and I have to clean it at least once a season.
I can tell just by looking at it, I don't need an article to tell me.

Canucker

If you skip the article and read what they actually did, it looks like washing off residue on a normal residential unit has very little effect on the heat transfer ability of the coils. They suggest that they're going to look at the system as a whole in a further study to see if there are other benefits. The only claim they appear to make is that detergent made no difference in that capability compared to the water only cleaning. 

In other words, surprise, yahoo came up with a way to twist the info and make a clickbait article 

jumper

Next we'll learn that dirty PV produces more juice?

Matt_67

Jughne has it….they tested coil s1 with a nominal cooling capacity of 42,000 btu plus heat of rejection at a rate of 5,760 btu. Horrific methodology.

ChrisJ

I don't worry about dirt 
I worry about dust grass,lint etc blocking airflow.

HVACNUT

A related article said its actually beneficial to put the drier vent as close as possible to the condenser and to use Bounce sheets so your equipment always smells fresh.🤪

pedmec

can i get my time back that i wasted reading that crap

RayWohlfarth

I respectfully disagree with the author. I know from my own testing that coil cleaning does lower the operating costs. Not only did I see a drop in head pressure, I saw a drop in amperage I had a customer who wanted to know how much they would save It was between 10-15% reduction

ChrisJ

RayWohlfarth said:

I respectfully disagree with the author. I know from my own testing that coil cleaning does lower the operating costs. Not only did I see a drop in head pressure, I saw a drop in amperage I had a customer who wanted to know how much they would save It was between 10-15% reduction

I disrespectfully disagree with them.
It's pretty much common sense that a fan cooled condenser needs good airflow to work right.

We don't need tests or studies or news articles to figure it out.

It's obvious.

And many out there are very badly plugged with dust and crap.

EBEBRATT-Ed

Most air conditioning service is dirty evaps or condensers. If the are kept clean amps drop and pressures drop=more efficient cooling and the equipment would last longer.

Of course if you a dope you can ruin a coil using a pressure washer to bend the fins or use the wrong cleaner on a microchannel coil.

retiredguy

30+ years ago in my last house, my neighbor and I were talking one day about the HVAC guy he had service his A/C unit. He told the guy that the unit would not keep the house cool in the warmest summer days. After the service was completed, the guy said that his A/C unit was too small and worn out. I told my neighbor if he should have asked "which one is it, too small or worn out". He asked me if I would look at his unit and give me my opinion. I got some tools like ref gauges & etc to check his unit. The condenser coil was very dirty and the head pressure was excessive. I cleaned the coil with his help and checked the rest of the system. Shazam, the unit again cooled as it was supposed to do. I had him call the service company and tell them that he wanted his money back that he paid them for their lousy service.

My neighbor was an accountant and knew nothing about fixing stuff but was very "cheap" and tried to fix everything himself. He called one day and told me that he could not un-solder the copper pipes going to his water heater. He was trying to replace the leaking water heater. His tool of choice was a "soldering iron". That is not a typo.

ChrisJ

retiredguy said:

30+ years ago in my last house, my neighbor and I were talking one day about the HVAC guy he had service his A/C unit. He told the guy that the unit would not keep the house cool in the warmest summer days. After the service was completed, the guy said that his A/C unit was too small and worn out. I told my neighbor if he should have asked "which one is it, too small or worn out". He asked me if I would look at his unit and give me my opinion. I got some tools like ref gauges & etc to check his unit. The condenser coil was very dirty and the head pressure was excessive. I cleaned the coil with his help and checked the rest of the system. Shazam, the unit again cooled as it was supposed to do. I had him call the service company and tell them that he wanted his money back that he paid them for their lousy service.

My neighbor was an accountant and knew nothing about fixing stuff but was very "cheap" and tried to fix everything himself. He called one day and told me that he could not un-solder the copper pipes going to his water heater. He was trying to replace the leaking water heater. His tool of choice was a "soldering iron". That is not a typo.

To be fair,
I've seen a few soldering irons that could probably do 1/2" and 3/4" copper.

I'm betting that's not what your neighbor was using though.

clammy

As I see it there are those who clean condensers and those who are clueless. Those who chose not to have there units cleaned are those who never have them serviced which is fine because there Hvac guy will just replace .
I seen guys use just a spray cans on a roof top I just shake my head and ask why there wasting there time w a half **** attempt get a spray foamier some cleaner and and some hoses . I figure those who think it bull to clean units is ok it’s ,good it help the manafactures and the economy ?
I figure w 410 w the higher head already and a dirty condenser is great for recipe for failure . I ve looked at calls for guys which they fear the unit was over charged and wanted to reclaim because the u it was shutting down at 650 psi because it was over chargerd . I pulled the top seperatored the split coil and cleaned after about 3 times spraying and hosing I reassembled everything and turned the unit back on and bang head pressure down to 300 . I made them carry there tanks ,cords and reclaim machine off the roof themselves I knew it only needed to be cleaned so I just dragged my hoses and sprayer off .
I think some don’t clean units cause they don’t know ask a refrigeration guy working on self contained refrigerators ,ice machines and indoor refrigeration condensers in kitchen space and they will tell you that they all need to be cleaned in some cases monthly . In some business practices instead of cleaning you just crank up the head pressure controller until it blows up then replace better for business .
I would think as in anything in life there’s short cuts and it being in our nature to be either lazy ,greedy , cheap and or a bit of all threee and include a little ignorance and you got the general nature of human being to be non trusting non believers so w that in mind when a customer complains about paying for preventive maintance and refuse to have it done because they see no valve in it I have no issues w that I just lose there number . I figure why deal w difficult people I just move on .
I recently cleaned a 30 year old r22 ge condenser could not even put your hand on the top blazing hot it was never cleaned . Showed the home owner then proceeded to clean after wards again showed the home owner and they where amazed especially since ever other Hvac contractor never even suggested it cleaning , after wards they stated the first floor had not ever cooled so quickly all from a simple condenser cleaning . A year later they stated there electrical bill had dropped slightly after the cleaning wow who would have thought that .
Clean you equiptment think of it as a house which I hope you clean ,
Peace and good luck clammy
Ps just cause it doesn’t look,dirty doesn’t mean it ain’t .

retiredguy

@chrisj yes, he was using a standard old soldering iron, had not turned the water supply off and had not even disconnected the 240 volt supply. At that point I told him I would help him and got out my "real" tools

ChrisJ

retiredguy said:

@chrisj yes, he was using a standard old soldering iron, had not turned the water supply off and had not even disconnected the 240 volt supply. At that point I told him I would help him and got out my "real" tools

With the pipe full of water I don't think the 1500-1800W ones I was picturing would've done anything either.

EBEBRATT-Ed

@ChrisJ & @retiredguy

The do make an electric soldering tool that will solder 1/2 & 3/4 in copper. We had a town hall where we were replacing 32 fan coils. The local fire dept demanded that we hire them for a fire watch (we had to pay them their OT rate during the day)

As a result we piped the chilled water mains in 3" Victaulic and the branches in PP copper. The fan coils came with sweat connections so we had to solder on those as the PP gun wouldn't fit in the cabinet. We did some in the parking lot to avoid the fire watch but some we couldn't do there. So I bought an electric "Hot Dog" was the name I think. and it worked good and with no open flame no fire watch

ChrisJ

EBEBRATT-Ed said:

@ChrisJ & @retiredguy

The do make an electric soldering tool that will solder 1/2 & 3/4 in copper. We had a town hall where we were replacing 32 fan coils. The local fire dept demanded that we hire them for a fire watch (we had to pay them their OT rate during the day)

As a result we piped the chilled water mains in 3" Victaulic and the branches in PP copper. The fan coils came with sweat connections so we had to solder on those as the PP gun wouldn't fit in the cabinet. We did some in the parking lot to avoid the fire watch but some we couldn't do there. So I bought an electric "Hot Dog" was the name I think. and it worked good and with no open flame no fire watch

Interesting.
Though, you do need to drain the pipe of course.

EBEBRATT-Ed

Had a service call on Winter St. in Boston years back (no parking area) on a stifling hot Saturday no AC call to a Layne Bryant store. After a 2 hour ride and trying to park I found

Two carrier Condensers on the roof R-22, Compressors are hot and tripping OL. I reset the HP on one and it started after a time and tripped HP quickly with the condenser fan at full speed. The other unit had no hp but had Carriers discharge line thermostat.

The condensers looked fine but the LL and condensers were really hot. Gauges confirmed HP

I looked for a place to get water and the only water was 3 floors below in the basement. I talked to the store manager who agreed to let me run Hoses through the store to the basement from the roof. I ran all the hose I had plus one of theirs and was still too short, so I fought the Boston traffic to Hope Depot and back.

Of course, I lost my parking spot and had to lug tools, hoses, cleaner and spray bottle back and forth.

In the city the coils get loaded with like an oily grime (which you can't see on the coils) and it comes out like black ink.

With a 2 hour ride home that was a full day or more.

We had a service contract with them so I questioned the tech that usually goes there as to why he didn't clean the condensers. He said the day he went the manager was a complete **** and wouldn't allow him to run hoses through the store.

I made sure I charged them plenty as OT calls were not included in the contract

EBEBRATT-Ed

@ChrisJ
Yeah, draining seems to help somehow.

ChrisJ

@EBEBRATT-Ed
Interesting.

I don't know about my condenser, but I've got a black scum on the sides of my pool skimmer and they've been doing a lot of road work in town. I assume there's been some kind of oil mist in the air that's collecting in the pool and ending up in the skimmer. And I would assume on everything else outside.

pecmsg

So according to the article I guess the filter in the evaporator is also a waste of money?

ChrisJ

pecmsg said:

So according to the article I guess the filter in the evaporator is also a waste of money?

Technically, the filter is next to the evaporator.

STEVEusaPA

The author probably thinks its a waste of time and money to get his teeth cleaned twice a year too.

JUGHNE

Sometimes filters do end up IN the evap coil!

Would that improve heat transfer?

GGross

@JUGHNE

No, only exactly 300 grams of laboratory approved synthetic dust will do that

PC7060

Silly questions, after you apply the cleaner; do you prefer to wash the coil by spraying from inside the condenser or at a angle from outside? 

Any preferred cleaner or just the one you can get off the shelf?

PC7060

PC7060 said:

Silly questions, after you apply the cleaner; do you prefer to wash the coil by spraying from inside the condenser or at a angle from outside? 

Any preferred cleaner or just the one you can get off the shelf?

@JUGHNE - any recommendations?  

Can you use highly diluted Dawn detergent?

Hope you all have a good holiday weekend. 

JUGHNE

PC, I haven't used anything but water for a long time.
That has gotten just about all the cond coils clean.
I try to always back flush the coils....inside out.
Might do down wash outside if really thick and then inside out.

There is one thick coil on an Eng Air wall mount AC on one phone building that I will probably foam next spring.

The cond foaming cleaner I have left is "Nu-Brite" acid solution. Outdoor use only....not for evp coils.
Probably 20 years old. Must be well rinsed when done....probably will kill plants...if there were any there at that site.

----what I read today is that Microchannel coils must use special cleaners---not the old school stuff I have left here.

BTW, they are often referred to as "Over Engineered" units BTW. A real nightmare of piping and controls.
Two stages....heat, re-heat, de-humidify and even cooling.

PC7060

@JUGHNE - thanks for the update.  I’ve got a pair of standard Goodman units so I’ll just use water as you recommend.  

Re the over engineered units; I’ve never been involved with anything like that!  

Hope things are going well out there in NE. 

JUGHNE

Just finishing up on my "last", hopefully, AC installs.

At the high school with the boilers.....the building addition required 2 existing furnaces to have the AC fired up on them.
Retiring a 20 year old 2 ton mini AC/HP and a 1 ton window unit. Putting a 3 ton split unit in.

Talked last night to a cousin near LA....he is cooking at 102.....AC never shuts off during the day.

I told him we shut our AC off 4 days ago just so CA would have some grid juice.

Forgot to mention that we cut the lawn sprinklers back to only every other day .

I think they have lawn watering police out there.