Pressure-washing AC coils?

[red_october]

Since probably in the next couple days I am going to overhaul the Coldspot including a complete cleaning, I'm curious about something I've heard: that you can pressure-wash Air Conditioner coils and that this, since it thuroughly remove debris, improves the effectiveness of the unit. Is it safe to do? Will it damage the fins or coils? Is it worth my while?

 

[launderess]

Yes, But

Cleaning with a hose and water is a better bet than hard pressure which may damage coils. Steam cleaning is also an option as well.

Whatever you do, make sure to cover all electrical components before "hosing down" and tip the unit back so water goes down and out. Allow all water to drain from the unit (again tipping slighly back), and dry for a day or so before putting back together/using.

You can spray down the coils with any good HVAC coil cleaner before hosing, but stick to the neutral biodegradable solutions instead of acids, as the later are less likely to damage coils/fins.

L.

 

[thor]

Yes!

In the TV company I work for there are about 30 semi-industrial grade and some 20 home grade split type air conditioners, to assist with the cooling capacity of the central air conditioner in certain rooms of the building, where there is a heavy concentration of electronic equipment.

The maintenance guys regularly clean the coils of the outside units with a tiny home grade high pressure water cleaner, which delivers a high pressure water spray. The nozzle they use delivers a flat wide horizontal water pattern.

The procedure is to electrically disconnect the units and wash the condenser coils from the outside of the units with an almost "downward" angle (slightly skewed off paralell with respect to the surface of the coil). They don't take any precautions as to protect (cover) the inside electrical components of the unit. In this way they avoid splashing with water the inner components of the unit. Please remember these units are prepared to keep working even under heavy rain. They let the units air dry from one day to the next before reconnecting the electrical supply and immediately start the units, which work 24/7.

You wouldn't believe the dirt that comes out from these condensers! The efficiency of the units is restored to like new condition.

 

[whirlcool]

When I got out outside condenser unit cleaned last year, the a/c tech took the top off of the unit and between the fins along the top of the unit he poured a solution of warm water with Dawn dishwashing detergent. He let it sit about 20 minutes and then, using a garden hose blew it out from the inside out and the outside in.
You wouldn't believe the dirt that came out!

 

[petek]

I just use the garden hose with a nozzle and spray away. Amazing the amount of "fluff" from dandelions and poplar trees etc. that coat the fins especially along the backsides against the house wall where no one usually looks. Moms was terrible when I looked at hers late last summer, it would never have crossed her mind to look at it. We have a flowering wisteria type vine growing on the wall over ours and when it drops its millions of little flowers they get sucked right in there.

 

[sudsmaster]

You can spray down the coils with any good HVAC coil cleaner before hosing, but stick to the neutral biodegradable solutions instead of acids, as the later are less likely to damage coils/fins.

Wondering here on the left coast tonite: wouldn't Wisk HE liquid work and well? I say this primarily because it's so neutral it barely cleans fabrics, so it should pose no threat to metals. And, like most all laundry detergents it's on the alkaline side, no danger of acidic corrosion from it. Plus its strong aroma would be a lot more welcome when diluted by infinite amounts of outside air.

 

[launderess]

Long as it is pH neutral and cleans/rinses easily don't thing it matters. Our AC guy says most of the newer units recommend the neutral stuff over the old fashioned acid.

There are even enzyme and other coil cleaners that claim they do not need to be rinsed, rather the condensed moisture will "rinse" away the muck and dirt to be drained away though the drain pan. Sounds like an interesting idea, and could save lots of effort.

L.

 

[kenwashesmonday]

In school we used Fantastik to soak the consender, then flush with a garden hose. Cover the motor with aluminum foil.

Ken

 

[whirlcool]

Safety First!

And whenever you are cleaning your coils, make SURE that the unit is not plugged in or disengage the circuit breaker!

 

[launderess]

Just hosing down the front of the condenser coils may not totally do the trick. Both front and back need to be done to make sure the condenser has optimal air flow.

Just cleaned the rear of my AC's condenser coils, caked with several years of pet hair, muck, dead insects and god only knows what else. Stuff was so thick in places thought it was a type of foam insulation. Used plain ole Lysol kitchen and bath cleaner, lots of warm water and a scrub brush. Several rinses produced the most ghastly black water and "lint".

Unit that before was cycling off every 10 or so minutes due to condenser over heating (so said the AC repairman), has been on now for over one half hour and the AC is streaming ice cold air. How cold? Incoming air near the register is about 82F, out going from the top of the AC is about 57F.

While you have the AC out and cleaning, it is a good time to see if the fan motor is one that requires oiling. My Friedrich fan motor takes 20 drops per port of SAE20 oil, once a year (according to the directions on the motor's plate). One was supposed to oil the motor every month during the first year of operation, but cannot imagine anyone pulling a behemoth like a Friedrich "WallMaster" out of the wall, and taking it apart every thirty days to get at the motor.

L.