A/C Cooling Coil PROBLEM SOLVED

rnbenton

rnbenton

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Dismanteled my A/C cooling water system yesterday for its annual spring cleaning. The tubing I am using is the nylon reinforced transparent plactic tubing and the inside of it looks really crudded up, almost black in many places.

So, my thought process is that if I have that much build up in the tubing the cooling coil has to be just as crudded. I am replacing all of the tubing but how do I clean out the cooling coil on the A/C unit?

Suggestions please.

Bob

I used a solution of CLR,Clorox and water run through the system using a small bilge pump and a 5 gallon bucket. I ran it for a couple of minutes until the system was full of the solution, stopped it and let it set for one hour then ran the rest of the solution through it. I then ran a bucket full of fresh water to remove all of the CLR and bleach.

I also have one of those syphon gizmos that keeps the condensation pan dry. It was fairly dirty so I removed it and cleaned it out really good and put it back in place.

Problem solved. Runs good, good water flow and the tubing looks so good I didn't have to replace it.

Bob
 
A little bit of crud inside the hoses will not be an issue but will be inside the coils

You need to use a bucket with a small bilge pump and circulate a cleaning solution like Ospho, barnacle buster, etc. some use muriatic acid but it s really strong stuff which is hard to dispose off
 
5 gallon homedepotlowes paintbucket. A cheap bilge / baitwell pump or a drill pump, some plastic tubing or garden hose and some CLR.

Connect the tubing / garden hose to the cooling coil entrance and outlet. Clamp them. Put the other ends of the tubing / hose in the bucket. Connect the pump to one of the tubes. Make a solution of CLR and water as if you were cleaning a coffee maker to fill the bucket. Put the pump in the bucket (or inline if a drill pump) and turn it on.

Depending on how crudded up the cooling coil is, it may take a couple of applications. If so, rinse between apps to get a feel for how far each app has gotten you.

There is a company named Rydlyme that does basically the same thing on a larger scale. If you go to their site (rydlyme(dot)com)you could get an idea of their setup and do something more permanent seeing you are tearing the whole thing apart anyhow.

HTH
 
Will a fairly strong solution of simple green work? If so, I can run it through all my tubing and clean that as well and maybe not have to replace it all.

Bob
 
I doubt Simple Green will do much, as you probably need something corrosive. I think I'd start with straight bleach.
 
I don't think so. Simple green is a cleaner. You want a de-scaler.

Instead of starting at the cooling coil, reconnect the existing input hose to it. Remove the hose from the output side of the strainer and start the process from there. If you want to get the whole system to include the pee hole, tap a hose barb in the pee hole (assuming the through hull is plastic) and run the hose back to the paint bucket. All you have changed is the location of the start/end points.
 
Bob, I made a dedicated recirculation system for desacling. Took only a limited amount of time, but I can now descale my diesel engine heat exchangers, genset and AC seawater cooling systems on a regular basis as needed. You can buy one from Barnacle buster for several hundred bucks or what I did is go to Harbor Freight and bought a agricultural spraying set up with a 5 gal tank and pump built into it. The pump has the correct type of rubber and viton internals as needed for reliably circulating descaling solutions. I added a few valves and got the right adapters for each of the systems I want to clean, and it is very convenient to use for a cost of $150.00 or less. Engines ran noticably cooler with no temp creep at WOT and the AC systems also seem to run slightly better.

For a solution it is best to use either Rydlyme or Barnacle Buster, they are the correct type of acid and dilute acid mixture strength with proprietary additives for improved descaling and cleaning. They are also mixed to a strength that is considered environmentally friendly and can be released into the environment. If you ever did decide make a system, I would post a few important concerns about materials used to ensure that the pump and plumbing last a long time and dont further contaminate your coolant systems with dissolved pump diaphragm and plumbing materials from use of pumps and supplies not meant for circulating corrosive acids.
 
quote:
Originally posted by Silver Lining

Bob, I made a dedicated recirculation system for desacling. Took only a limited amount of time, but I can now descale my diesel engine heat exchangers, genset and AC seawater cooling systems on a regular basis as needed. You can buy one from Barnacle buster for several hundred bucks or what I did is go to Harbor Freight and bought a agricultural spraying set up with a 5 gal tank and pump built into it. The pump has the correct type of rubber and viton internals as needed for reliably circulating descaling solutions. I added a few valves and got the right adapters for each of the systems I want to clean, and it is very convenient to use for a cost of $150.00 or less. Engines ran noticably cooler with no temp creep at WOT and the AC systems also seem to run slightly better.

For a solution it is best to use either Rydlyme or Barnacle Buster, they are the correct type of acid and dilute acid mixture strength with proprietary additives for improved descaling and cleaning. They are also mixed to a strength that is considered environmentally friendly and can be released into the environment. If you ever did decide make a system, I would post a few important concerns about materials used to ensure that the pump and plumbing last a long time and dont further contaminate your coolant systems with dissolved pump diaphragm and plumbing materials from use of pumps and supplies not meant for circulating corrosive acids.

Click to expand...


Yes, I would really like to see the details of what you have set up. Sounds very interesting.

Thanks,
Bob
 
Yeah, sounds like a great invention. I would test different types of descaler solutions. Copper is one of them metals that is easily attacked by acids 'n stuff.
 
I have a set up with a pump on a 5 gls bucket and I use white vinegar which I buy at Bjs or Cosco circulate thru the system for 15minutes and does a great job.
 
Bob, within a day or two I will post the details of my system design with various pump and materials requirements. I spent some time understanding the proper materials for the tank, pump (diaphragms and valves), input/output tank valves, connectors and hoses and want to pass on accurate details. The systems from Rydlyme or Barnacle Buster use the correct materials and this is part of why they cost what they do, but it can be done for way less money. Also, I got a hold of a Navy report detailing studies of different descaling solutions (hydrochloric versus phosphoric) and their apparent plusses and minuses that you may find inetresting.

I keep my system on board under the galley floor so when I get a chance I will take and post a few pictures
 
The sprayer is a Northstar spot sprayer 10 gal model from Northern Tool. It comes with a 10 gal polyethylene tank, name brand pump made with correct materials (Viton valves and santoprene diaphragm). The pump is set up with leads for a 12 V battery with on/off switch. Cost is $90.00 and includes intake and spray hose. The pump is only 1 GPM and 40 psi, which actually works very well, you just don’t need to circulate more fluid than that. In fact I usually run it for 15 minutes and then let the fluid sit for 5 or 10 minutes then recirculate again for a total of 2 hrs per engine.

I added lengths of reinforced pvc hose for the inlet and outlet runs to the engine. I added a return port on top of the tank and polyethylene valves for the in and out lines at the tank. I removed their sprayer nozzel and added the valve and line that goes directly to the engine. I also put together an assortment of reducers etc. to hook up to the engines, AC and genset. I got all of the fittings, valves, and hose from Home Depot or MSC Industrial supply (either pvc or polyethylene). The tank sits above the engine room in the cockpit while circulating which is important so there are no air pockets in the entire circulation path.

After removing all zincs, I run the fluid into the heat exchanger after the sea water pump (a fitting screwed into one of the removed threaded zinc holes) and the return line is plumbed into the seawater hose where it goes into the exhaust (pull it off the exhaust mixer). I run the system with 5 gallons of dilute acid. One commercial Co runs his directly into the seawater pump with the impeller removed, but that is a little difficult on my engines and the feed directly into the xchanger zinc port works well.

It is important that the pump have viton valves and santoprene diaphragm materials, other materials are not appropriate for extended recirculation of hydrochloric or phosphoric acid. PVC is good with acids and polyethylene is even better for the tank, hoses and valves.

The Navy study I mentioned looked at dilute HCL and Phosphoric acid for use in descaling seawater systems. In general, after extended exposure to the acids, hydrochloric acid was somewhat less corrosive than phosphoric acid but they studied extended exposure to 50% dilute solutions whereas Barnacle Buster and Rydlyme use 10% solutions for short periods of time so the corrosive differences may not be a big deal. The two main brands use different acids, one Phosphoric and the other HCL. The other interesting thing in the report is that the descaling solutions remove a protective native coating that metals form in seawater, but this coating grows back within a few weeks time with either acid.

The descaling treatment was very effective on my diesel seawater cooling systems and the WOT temp creep completely disappeared. Hope this helps.
 
quote:
Originally posted by rnbenton

quote:
Originally posted by Silver Lining

Bob, I made a dedicated recirculation system for desacling. Took only a limited amount of time, but I can now descale my diesel engine heat exchangers, genset and AC seawater cooling systems on a regular basis as needed. You can buy one from Barnacle buster for several hundred bucks or what I did is go to Harbor Freight and bought a agricultural spraying set up with a 5 gal tank and pump built into it. The pump has the correct type of rubber and viton internals as needed for reliably circulating descaling solutions. I added a few valves and got the right adapters for each of the systems I want to clean, and it is very convenient to use for a cost of $150.00 or less. Engines ran noticably cooler with no temp creep at WOT and the AC systems also seem to run slightly better.

For a solution it is best to use either Rydlyme or Barnacle Buster, they are the correct type of acid and dilute acid mixture strength with proprietary additives for improved descaling and cleaning. They are also mixed to a strength that is considered environmentally friendly and can be released into the environment. If you ever did decide make a system, I would post a few important concerns about materials used to ensure that the pump and plumbing last a long time and dont further contaminate your coolant systems with dissolved pump diaphragm and plumbing materials from use of pumps and supplies not meant for circulating corrosive acids.

Click to expand...


Yes, I would really like to see the details of what you have set up. Sounds very interesting.

Thanks,
Bob

Click to expand...


Rydlyme, Barnacle Buster, phosphoric acid or deluded muratic acid is the way to go. Vinegar is to weak of an acid unless you are using it as a weekly preventative solution like say in your toilet/head to get any heavy scale out.

The coils in most if not all A/C units are not purely copper. And most manufactures used to recommend using a diluted muratic solution to clean them out with before less caustic alternative solutions like Barnacle Buster where available.

If you make up your own descaling system in many cases with a couple of adapters and some extra hose you can, in many cases, use it to descale you engine, transmission, and genset heat exchangers with out removing them from the engines.
 
quote:
Originally posted by rnbenton

Click to expand...


Glad it seemed to work out for you. But I'm not sure you should be mixing bleach and acid. In any case the bleach is unnecessary for cleaning out the coils.

As an FYI for the future, highly diluted CLR may not be strong enough to do a thorough job of cleaning real dirty coils.
 
quote:
Originally posted by Capt. Bill1

quote:
Originally posted by rnbenton

Click to expand...


Glad it seemed to work out for you. But I'm not sure you should be mixing bleach and acid. In any case the bleach is unnecessary for cleaning out the coils.

As an FYI for the future, highly diluted CLR may not be strong enough to do a thorough job of cleaning real dirty coils.
Click to expand...


Hey Bill, how goes it?

When I got into cleaning everything out, I saw a lot of what looked like, algae (organics). So, I decided to add bleach to the mix. Also, it was a fairly strong mixture, not really HIGHLY diluted and I only let it stay in the system for a little while. Seemed to work very well and now I have excellent water flow.

As always, thanks for your input.

Bob
 
Using the 10 gallon north star tank -

How big are the output and input lines?
Can you mix one tank full and do everything? 2 engines, genny, an 2 AC?
Is this the rectangular tank/sprayer unit for use on an ATV?
 
John, I mix 5 or 6 gallons in the tank, do the first engine, then add another gallon or two as needed then the next engine and then the genset and ACs with what remains. You will find that you want to let the first gallon run out of the circulation system then close the circulation loop as there is a gallon or two of residual water in the seawater system. This is the rectangular tank/sprayer for ATV use. You will see the solution foam initially and then settle down as the deposits are dissolved.

I have to go to the boat and measure what I used for inlet and outlet hose sizes, but in general with fluid systems you want a smaller higher pressure line, I think it is maybe 3/8 for the pump outlet to heat xchanger. Then a 1/2 inch return line from the exhaust mixer. I like the Rydlyme as it is hydrochloric acid based which is slightly more gentle then the phosphoric acid solutions.
 
Thanks for the reply. I just ordered on amazon for $59. Going to HD this weekend for the rid Lyme.
 
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