If this were your condenser coils???
- Thread starter Ken Cross
- Start date
Depends on what kind of sailing you're gonna do short term. I don't think the squirt will do much. To inhibit further rust, you need to brush the loose stuff off and apply a conversion coating and paint. And that might affect the caloric transfer properties. I know you just bought the boat so maybe just run it till it dies....but it should definitely be on the refit list
You do not want to paint them it will definitely inhibit efficiency. That rust is the accumulation of some years; just treat for the rust, clean and repeat once a year. Sorry the manufacturers have not come up with any efficient cover protection for the coils and refrigeration repairmen spend hours just cleaning dirt and grime from the coils of poorly working A/C units or refrigerators.
Well if paint would inhibit, so might the rust treatment. It is a coating. At least what I've used. (Corroseal)
I would try vacuum them first and use a paint brush to help remove some of the deposits. If you have access to compressed air you can blow that across the coils first and then vacuum. After cleaning It might be worth leak checking with a freon detector to ensure that there no freon leaks. Then base further action on the results.
Can someone explain the science behind not painting an A/C condenser? I've install brand new condensers that came out of the box painted. Yes, dirt, dust and grime will hinder air flow over the coils and therefore reduce efficiency but I just don't understand how a coat of paint will reduce heat transfer.
I wouldn't touch them, it could make matters worse. I suspect the coils have iced up many times over the years & the rust is from the ice melting off the coils when the compressor shuts off. That's why the bottom portion of the unit is worse than the top, gravity. Start saving your money.
Well, yes, the factory does have to use some paint, possibly one specially formulated for the application? But layers of paint lessens the heat transfer. Watch the DIY channels and see how often they say not to paint room radiators (but people do anyway). The rust inhibitors are not a paint, they just "neutralize" the rust and "inhibit" the oxidation process- without paint buildup. And you would not treat the entire cooling coil, just where the rust is..
I do not want to sound argumentative but I have never heard advice to not paint radiators. In fact I just did a quick google search and found nothing, well I found plenty but it was all DIY advice on how TO paint your home radiators
I've done a lot of automotive HVAC work in my younger days and the principle of paint reducing heat transfer is frankly lost on me. Sure, multiple coats of unusually thick paint could cause an issue but a single coat of rustoleum or similar product is going to heat up with the metal of the condenser and transfer it's heat within milliseconds. Remember all that is being accomplished by the condenser is changing the state of the refrigerant from a hot gas to a liquid. The temperature of the liquid has no effect on the A/C performance, it just needs to remain in a liquid state. Painting a condenser is not going to lower it's efficiency to the point that it can no longer "condense" the vapor.
In other words it's not like the cooler you can make the condenser the cooler the A/C, or freezer or reefer, will be. It just doesn't work like that.
If you do not stop the oxidation process the coils will sooner not be able to hold refrigerant. I'm not saying scrape the rust off but use a cleaning product in spray or gel form. Some manufacturers do offer coated coils where a protective coating is usually baked on in the manufacturing process. These coils are sized and designed so that the unit will operate properly with the coated coils. I do not know of any effective aftermarket coating product as none seem to be recommended by the manufacturers. Some of these products do work temporarily but then start flaking off adding to diminishing the air flow. Periodic cleaning will do the job and keep your unit working efficiently
chrisings I understand your concern but my objections to paint as a protective cover are not solely based on heat transfer, cooling coils make a poor surface base for paint, in short time the paint dries, cracks, starts peeling and flakes and the removal of those flakes becomes a never ending job. Those flakes will reduce air flow and unit efficiency. It is much easier just to treat the rust and clean the coils once or twice a year.
Those are good points and I agree. I'm just trying to either debunk the myth of painting your condenser will reduce efficiency or have someone prove me wrong. As I said before, all a condenser does is condense. The evaporator, on the other hand, is a completly different story. The evaporator should never be painted.
Benny's right. Commercial coils come with many options to coat coils for sea, industrial and urban environments. The coils themselves are thin to begin with and the coatings even thinner.
Misfit, where do you get the idea that condenser coils freeze? Their purpose is to reject heat.
Theoretically, any additional material added to the coils will affect the heat transfer. Paint, not so much, but it will. The ideas already expressed about paint flaking off are more troublesome in my mind and a much better reason to not do so.
Misfit, where do you get the idea that condenser coils freeze? Their purpose is to reject heat.
Theoretically, any additional material added to the coils will affect the heat transfer. Paint, not so much, but it will. The ideas already expressed about paint flaking off are more troublesome in my mind and a much better reason to not do so.
People have differing opinions for differing reason. Sometimes it just comes down to common sense. Take a grander scale, your home furnace. It probably has foam or fiber insulation around the two lines from outside to inside your house. WHY? To keep the cold or hot medium INSIDE the tubes from being affected by the hot or cold air AROUND the tubes- thus stopping temperatures from transfering the temperature of the tubes and its content. However, on the boat fridge, you WANT the hot tube's medium to be cooled by the outside air. And that's why anywhere you have coils, you need room for air to circulate- even if there is a fan.
And just becasue you've never seen or heard of the disadvantage of painting does not tmean that it is not right. You can't prove a negative- and probably shouldn't need to.
Stu...
You need to come East in a hot, humid August. I've had the outside coil unit of my AC/heat pump freeze up as well as the coils in my car's AC system on several occasions. Leave your car's AC setting on Max too long with the recirculation (no outside air) engaged and it will happen.
You need to come East in a hot, humid August. I've had the outside coil unit of my AC/heat pump freeze up as well as the coils in my car's AC system on several occasions. Leave your car's AC setting on Max too long with the recirculation (no outside air) engaged and it will happen.
Because I've been in the HVAC/Plumbing industry for 42 years
The purpose of the coil is to reject heat however it's doing that with freon. So in Ken's case there could be insufficient air flow across the coil due to inadequate ventilation of his compressor locker or the freon level could be slightly low. Coils ice up because they can't reject the heat, the compressor finally shuts off on safety, the cycle repeats itself until it either dies or there's no more cooling & you send up a flare to the local refer tech.