Cleaning Of Split Air Conditioners.

[Dazinoz]

I am doing this post as I have read a number of posts with people asking about their AC is not performing good or asking about cleaning of their AC. Many people reply that the filters in the indoor unit need to be cleaned, possible clean the fins in the indoor unit or may need a refrigerant top up. While all these could be correct not a lot of people mention cleaning of the fins in the outdoor unit.

 

Recently I was at a friends room (apartment block) and had just had her AC "cleaned". She said they cleaned the filters inside. I saw how dirty the outdoor unit was and asked her had that been cleaned. She didn't know. Just then one of the cleaning crew walked past and my friend asked her had the outdoor unit had been cleaned. She replied (in Thai) and indicated a rotating motion with her arm then walked off. I asked my friend as to what she said and she had said there is only a fan in it and nothing to clean. So much for a professional cleaning crew.

 

Anyhow my bedroom AC recently started to drop in performance. It runs almost overnight. It had been cleaned professionally around 1 year ago and I witnessed the clean with a high pressure water cleaner. It was extremely dirty then and worked well after.

 

So I just cleaned it again and made this video to show how dirty the outdoor unit can get in 12 months especially places with high pollution like here in Chiang Mai. I continued cleaning for several minutes after I stopped video to get it very clean.

 

I hope someone gets some benefit from this post.

 

.

[MrBrad]

WOW!

[tomdfc]

Well done & thanks for the post.

[geoffbezoz]

Good post but perhaps it would be wise to state that before dismantling it and pressure jetting it, you should ensure it is electrically isolated.  There is sure to be some numb nut somewhere who overlooks that.

[metisdead]

Some troll posts and replies have been removed. 

[sfokevin]

I would shut the power off at the main or wear flip flops before doing this...

[johng]

21 hours ago, Dazinoz said:

show how dirty the outdoor unit can get

Yes they get very dirty.. keeping them clean will help cooling efficiency and save electricity.

 

In my situation our balcony serves as  a kitchen and the aircon compressor unit is near to the  gas stove, my wife likes frying food and the grease got all over the place especially the aircon compressor..I had to fit an extractor hood to contain it which has helped immensely

now all (90 %)  the grease gets stuck to the hood but its much easier to clean than the aircon compressor unit.

[Dazinoz]

53 minutes ago, geoffbezoz said:

Good post but perhaps it would be wise to state that before dismantling it and pressure jetting it, you should ensure it is electrically isolated.  There is sure to be some numb nut somewhere who overlooks that.

I agree but I did not do a detailed post on how to do it I did the post to show why it needed doing. 

 

But I should have added to be done by experienced person.

Edited April 27, 2019 by Dazinoz

[Dazinoz]

19 minutes ago, johng said:

Yes they get very dirty.. keeping them clean will help cooling efficiency and save electricity.

 

In my situation our balcony serves as  a kitchen and the aircon compressor unit is near to the  gas stove, my wife likes frying food and the grease got all over the place especially the aircon compressor..I had to fit an extractor hood to contain it which has helped immensely

now all (90 %)  the grease gets stuck to the hood but its much easier to clean than the aircon compressor unit.

And grease would be much worse that just the average airborne dirt.

[Dazinoz]

48 minutes ago, sfokevin said:

I would shut the power off at the main or wear flip flops before doing this...

Yes the power was off (electrical background). But I did not do a detailed post on how to do it I did the post to show that it needs doing.

 

But I should have added to be done by experienced person.

Edited April 27, 2019 by Dazinoz

[johng]

16 minutes ago, Dazinoz said:

And grease would be much worse that just the average airborne dirt. 

Yes I had to use a rather nasty chemical which did an excellent job...but it stained my black tile worktops, any bare metal it came into contact  with  and ruined the coatings on my  spectacle lenses its also very irritating to the skin...so next time I used it  I wore googles and  long arm length rubber gloves..and made sure to thoroughly rinse with clean water whatever the chemical came into contact with.

 

cal

[dddave]

I also cook on my balcony and the fan unit picks up a lot of grease.  I try to remember to turn the ac off when I'm actually cooking but often forget.

I have found that ordinary laundry detergent mixed in a strong solution with water is very effective removing grease from the grill fins. I use a medium stiff, fiber bristle brush to apply the solution. I let it stand for a few minutes, then scrub top to bottom, rinsing with a garden hose.  Seems to clean very well. Rubber gloves advisable.

[eyecatcher]

Thats a great post.

Whilst most people will never actually be bothered to do that themselves, its important to realise that cleaning the aircon is not just a one part job.

Cleaning those fins certainly improves the cooling efficiency and at the same time its saving you money.

 

[vivid]

Just a tip......

 

If your condenser unit installation is such that the fins are rather inaccessible, you can open up the top cover (only 4 screws usually, and give the top cover a good jerk upwards as it might be stuck due to some corrosion) and hit it with the pressure washer or some car wash pump. 

If your tap water pressure is > 50 PSI, then it might work also with a good concentrated steam nozzle and a good degree of patience (do not fan the stream out).

 

If you are only using tap water pressure, then it is a must to use a cleaner of some sort.  Any multipurpose floor cleaner type is fine.  Use about 500ml to 1 litre of it in concentrate form on the coil and let it dwell for 15 minutes.   If the coil is extremely dirty, then an alkaline coil cleaner might be needed.   

 

If you are using a pressure washer and a 15 deg stream, just hit the coil from about 6 inches away is fine.  The fins won't be bent if you do not go nearer than 6 inches and am only using an entry level one and a 15-25 deg nozzle (eg 1200W, 70 bar).  Also. a caustic and corrosive alkaline coil cleaner is not needed, just your normal floor or window/glass cleaner is fine.  Important thing is to let it dwell for 15 mins.

And if 1 round of cleaning is insufficient, do it 2 times, there is no hurry.   Be very careful with the alkaline coil cleaners if you decide to use it for the external unit.  It is not different from your drain cleaner, it's potassium or sodium hydroxide at a decent concentration and even after diluted say 1:5 it is still at pH 13+.  Get it into your eyes and an A&E trip to the hospital is pretty much confirmed even if you managed to flush it within 20 seconds, pray that there is no tissue scarring.

So it is best to leave the alkaline coil cleaners to the pros and just use normal cleaning agents, and a pressure washer or any other medium pressure sprays.

 

 

 

 

 

[vivid]

The external condenser unit is the easiest to clean.  Basically is just switch off the power, get some cleaning agent on the coils (optional), blast with some medium to high pressure water.  Those 12V car wash pump or portable pressure washers like Worx Hydroshot @ 400 PSI is fine.

If you have medium to high pressure washer hitting the coils, then you do not need much of a powerful cleaning agent at all, or even none if it's a high pressure washer.  Of coz, watch the pressure  and nozzle distance (use a 25 deg nozzle, very safe) and also try your best to hit the coil perpendicularly.  If you are quite experienced, you can even use a 15 deg nozzle and distances closer than 6 inches.  With just some floor/multipurpose cleaner or windows/glass cleaner, you can get the coil extremely clean.

 

The indoor coil is not so easy as there are more stuff to dismantle, and basically you need a water catchment bag (I think lazada th shd sell).

If your pressure washer has variable pressure adjustment (eg Karcher variojet VP 160, VP 180 nozzle heads, sold seperately) then it's even better for indoor use.

 

 

 

 

 

[vivid]

BTW, the condenser unit fan motor is water proof, at least for the major brands.

 

I do not open up the condenser unit, i just whack it externally with the pressure washer at full pressure.  So far after cleaning more for more than a dozen times, so far so good, the motor is still going strong.

 

The condenser units are designed to be have pretty good weather proofing, at least for the fan motor part.  They are able to survive things like typhoons and stuff, even cat 4/5 super typhoons in Taiwan etc.....maybe not a direct hit from the pressure washer at 0 deg, but if you are spraying from the coils outside (so the water velocity is very much reduced after travelling through the coil), there shouldn't be any issue.

[moontang]

pressure washer is a mistake and destroys the electrolytic bond between the fins and the copper tubing.  The foams can also etch aluminum.  The real pros use a garden hose with a special fitting to reach in and spray sideways.  Some carry a backpack type applicator with a pump, which is no where near a pressure washer.  A pressure washer will also very easily disfigure the fins.  I give the OP credit for not using it on high pressure.  The tech teams are a very distasteful joke in Thailand.  Sorry, three guys from the game shop do not equal one qualified technician.  They often do not put the blower back the way it was made.  And you can bet your arse; they aren't grounded.

[moontang]

3 hours ago, vivid said:

BTW, the condenser unit fan motor is water proof, at least for the major brands.

 

I do not open up the condenser unit, i just whack it externally with the pressure washer at full pressure.  So far after cleaning more for more than a dozen times, so far so good, the motor is still going strong.

 

The condenser units are designed to be have pretty good weather proofing, at least for the fan motor part.  They are able to survive things like typhoons and stuff, even cat 4/5 super typhoons in Taiwan etc.....maybe not a direct hit from the pressure washer at 0 deg, but if you are spraying from the coils outside (so the water velocity is very much reduced after travelling through the coil), there shouldn't be any issue.

the fins should be cleaned from inside out...

[vivid]

1 hour ago, moontang said:

pressure washer is a mistake and destroys the electrolytic bond between the fins and the copper tubing.  The foams can also etch aluminum.  The real pros use a garden hose with a special fitting to reach in and spray sideways.  Some carry a backpack type applicator with a pump, which is no where near a pressure washer.  A pressure washer will also very easily disfigure the fins.  I give the OP credit for not using it on high pressure.  The tech teams are a very distasteful joke in Thailand.  Sorry, three guys from the game shop do not equal one qualified technician.  They often do not put the blower back the way it was made.  And you can bet your arse; they aren't grounded.

1 hour ago, moontang said:

the fins should be cleaned from inside out...

 

In a normal setting, when washed at an enough pressure, washing from the external or internal doesn't really make much of a difference, especially if you are using a neutral pH cleaner for the cleaning process.  If it were to be so critical, then it'd also mean that the indoor evaporator fins should be cleaned from the inside out as well.   

 

From what I have seen on youtube with pros doing the cleaning, that isn't the case all the time with both indoor evaporator coils as well as external condenser coils, in western to eastern countries all around the world. I think i have seen more techs cleaning from the outside than from the inside.

 

But of course if we are talking about an extremely dirty and clogged coil due to some special environmental factor(s), it's best to clean from the inside out (after physically removing any external thick layer of caked up dirt eg in settings like having pollen/cotton and similar very big particulate matter around).

 

The evaporator coil cleaners/multipurpose/glass cleaners are more than good enough (containing surfactants, glycol ethers, ethoxylated alcohols and other solvent/detergent cleanersz etc), if one has been doing the cleanings at least once a year. Preferably 2-4 times yearly i guess for CM city.  I hail from a place that has much less pollution/coarse particulate matter than CM city.

 

 

Anyway just to share more, I have cleaned my 2 condenser units well over a dozen times for each unit, probably over 20 times even.  The pressure washer at around 70 bar at around 15-25 deg nozzle angle at around 6 inches does not strip the bluefin/goldfin PU/epoxy protective coating and would not expose the fins/refrigerant pipings to corrosion.

 

 

This is a pic of one of my 11 year old units. (Panasonic).  When you are viewing through the coil, it is totally clear, fins have no clogs at all.

 

 

 

As for not opening the CU up, it's more of a personal (lazy) thingy : I don't want to open up the top cover as i don't wanna wrap up the electricals or run any risk of accidental spray messing it up.  More importantly, it's a very fast process this way, less than 1 minute per CU and you are done, if you are using a pH neutural cleaning agent then add 5-10 mins of dwell time.

Cleaning it 4X yearly is of no issue, others can do even more frequent cleanings.  The idea is not to let the gunk build up and cake up a thick layer.   The good thing is that i have around 2 feet of clearance between the wall and the fins as the CUs are on a concrete ledge.  The only real issue is that i am living in a high-rise apartment, so i gotta wait for rainy days to clean it.

For those folks living in a house, it'd be even easier. 

 

 

 

Just some vids (just posting the US vids as this is a farang forum, there are many more all over the world. No destroyed fins, as long as you know what you are doing.

 

 

 

 

Edited April 28, 2019 by vivid

[vivid]

Actually I don't really have an OCD for having a clean external condenser coil

 

Due to having allergies and also kids having similar allergies (luckily for them it's mild, no progression to asthma etc, not like my sis' kids), i am very particular about the indoor FCUs. Don't want any mold build up, or having the FCUs a haven for dust mite droppings.    I clean them every 1-2 months, 3 units of them, and also at my parents place since my kids spend significantly time there as well.   So that's 6 units every 1-2 months.   In addition to having HEPA filtration. 

That's a good few hundred cleanings.   ????

 

Sure beats having antihistamines regularly, so the OCD is probably a good and justifiable one. 

Edited April 28, 2019 by vivid

[vivid]

BTW, if you really are afraid of stripping the protective PU blue or gold coating on the condenser coil, it's probably more prudent to avoid the alkaline coil cleaners than to avoid high pressure jets.   If you really have a need to use it, dilute it appropriately (different alkaline coil cleaners have differing concentrations) and wash more times.

 

Picture is self-explanatory

 

 

 

[moontang]

On 4/27/2019 at 10:37 AM, johng said:

Yes I had to use a rather nasty chemical which did an excellent job...but it stained my black tile worktops, any bare metal it came into contact  with  and ruined the coatings on my  spectacle lenses its also very irritating to the skin...so next time I used it  I wore googles and  long arm length rubber gloves..and made sure to thoroughly rinse with clean water whatever the chemical came into contact with.

 

cal

https://www.permatron.com/prevent-installs/stop-cleaning-coils-with-corrosive-solutions

[hmficc]

Now, clean your lungs.

[vivid]

Share another video as practical eg, at this kind of distance and spray angle, it is very safe if you are using entry-level pressure washers, and it is a pretty efficient way of cleaning the Condenser unit.

 

The only thing i'd do is to hit the coil at a right angle perpendicular to the coil.  This also assures you that there is full and ample penetration of the coil, next time you do a wash try to notice the velocity of the water exiting the coil when you are hitting it perpendicularly and then hitting it at a 45 deg angle.  There is a significant difference, it's likely that hitting it from an acute angle, the water velocity exiting the coil is very slow.

 

If you are ok to spend the time and able to open up the top and front cover of the CU, then no worries you can clean from both the inside and outside.  Really depends on your situation and how bad a condition the coil is.

 

If you have been judiciously cleaning the external and internal units, then no worries, there is likely to be very very little dirt build-up even if it's CM city air, every washing would be a breeze.

 

 

 

 

 

This is likely to be a 2000+ 3000 PSI @ 10-20L per minute flowrate very powerful pressure washer. 

 

 

 

 

Daikin Thailand

 

 

Edited April 29, 2019 by vivid

[vivid]

On 4/27/2019 at 11:37 AM, johng said:

Yes I had to use a rather nasty chemical which did an excellent job...but it stained my black tile worktops, any bare metal it came into contact  with  and ruined the coatings on my  spectacle lenses its also very irritating to the skin...so next time I used it  I wore googles and  long arm length rubber gloves..and made sure to thoroughly rinse with clean water whatever the chemical came into contact with.

 

cal

 

 

I guess sometimes it can't be helped, the coil could be so plugged up that there is no choice but to turn to the alkaline coil cleaners.  Even a pressure washer + evaporator coil cleaner or similar pH neutral or mildly alkaline cleaning agents cannot clear it.  So gotta use the corrosive cleaners (esp to aluminum)     Remember to use protection and don't let it dwell for any longer than 2 minutes, and remember to rinse it real good.   The folks do a full dismount of the evaporator coil is coz then you'd be able to fully flush the alkaline chemical away from all angles including all internal surfaces of the coil, it's not that easy to flush the stuff away esp if there is a prescence of oil/grease........same as what your fingers would feel as a very difficult to wash away slime with drain cleaners/mold and mildew cleaners, need hard physical scrubbing.    If the stuff stays on the coil, even if it's diluted, it's going to cause serious corrosion + gas leak issues over time if this is done repeatedly.

 

 

 

 

Bonus video  

 

 

Edited April 29, 2019 by vivid

[VocalNeal]

 

Similar available at a Tesco or BigC near you. Cheaper if you happen to pass an AC supplies shop. 

For outside Windex is OK and a simple garden hose pipe.

 

Edited April 29, 2019 by VocalNeal

[Dazinoz]

4 hours ago, VocalNeal said:

 

Similar available at a Tesco or BigC near you. Cheaper if you happen to pass an AC supplies shop. 

For outside Windex is OK and a simple garden hose pipe.

 

Tried that one or a similar from Big C on indoor unit. Not very successful. Doubt it would have much affect on dirty outdoor unit.

[VocalNeal]

Strange i used it all the time on the indoor one. Wife even said it smells nice.

[Dazinoz]

1 hour ago, VocalNeal said:

Strange i used it all the time on the indoor one. Wife even said it smells nice.

Good for you. You didn't waste your money on it like I did. The smell nice was only advantage I got.

 

[vivid]

The external condenser coil would also benefit from a cleaning after the smoky season, which is like around now.

 

BTW, i did measure my indoor FCU coil and outdoor condenser coil.  The external coil is around 2.5 to 3X the size of the indoor coil  (L x W x depth of the coils)....so in terms of heat exchanging performance, the external coil can stand up to more dirt and grime vs the indoor coil, and besides you also need to contend with indoor air quality with regards to the indoor coil, which is of zero issue with the outdoor coil.

 

I guess in a way, you can say that if you are washing the indoor unit once every 2 months, in theory you can schedule an external unit wash once every 4-6 months.   

Edited April 30, 2019 by vivid