DuoTherm Cleaning?

[lonestarace]

Hi All:

We have DuoTherm ACs/heat pumps on the roof of our 99 Monaco Exec and need to clean the evaporators, condensers, and drain lines.

Any suggestions on how and/or what to do or not to do? We already have the plastic covers off and the metal insulated evaporator covers off too.

Thanks in advance

Don, Lisa, and Alexa

[Ray,IN]

I use a spray can of foaming coil cleaner, it is just a strong detergent I think. Be careful not to bump the aluminum fins and bend/crush them while working. We know we can't use a garden hose to flush the cleaner and dirt away because we'll get water in places it doesn't belong. I use a garden sprayer to flush the coils/fins after using the cleaner. This has a strong enough water stream to get the job done, yet uses a relatively small quantity of water.
Mine has several tiny drain holes around the sides of the drip-pan which become clogged quite easily it seems. It's not easy to locate them because the cover screw holes are nearly the same size, and I get them confused. I use a same-size drill bit to clean out the drain holes.
If you don't want to use the cleaner and water flush, I have used an air hose set to 60/65 psi to blow crud from the coils; inside out of course. I really can't tell any difference between these two cleaning methods.
If you have many bent/crushed fins, buy a fin comb at most any good hardware store. It's easy to use, just takes a little getting used to; sure reduces the compressor work load.

["007"]

Here is a pretty good write up by Oemy about cleaning.

[lonestarace]

Thanks for the input Ray & 007.

Here is what we found and what we did about it. These units are Dometic DuoTherm Penguin heat pumps, #630215321. Remember, this is a 11 yr old coach and they're only new once:

1) The exterior ac shrouds needed replacing because they where cracked and brittle. $100ea at CW. We tape the new wx strip in place on the ac unit itself, then apply a bead of silicone to the wx strip, then put the shroud on, thus glueing the wx strip in its proper place to the shroud. The wx strip is inexpensive and can be purchaced @ HD or Lowes.

2) The air circulation system for the coach interior was dirty so it was decided to clean it as best we can. I replaced the insulation on the inside of the evaporator covers. They were dirty and falling apart. I used a non porous silver foil covered 1/4" thick bubble wrap type material that can be purchased in a large roll and is commonly used to make thermal barriers for MH windows. I vacuumed the faces of the evaporators, and their tanks, with the soft bristle brush vacuum cleaner attachment, then sprayed them w/simple green, and rinsed with fresh water by spraying the water thru the evaporators with a siphon type blow gun. Care has to be taken not to overflow the water into the interior of the coach. I used a towels up top and a large drip tray inside to prevent any accidents. The squirrel gage fans were dirty. I cleaned them by vacuuming with the soft bristle brush. This minimizes the amount of debris that falls down into the duct. We also removed the vent registers and played chimney swift in the air duct that runs the entire length of the coach.

3) We cleaned the condensers with simple green and a fresh water rinse from a garden hose.

4) Next we cleaned the condensation hopper tanks and drain lines. There is a t-fitting where the hopper tank drain hoses attach to the main drain hose that comes out the bottom of the coach. We disconnected the main drain hose at this t-fitting and blew a bleach/water solution down thru it. We blew out the hopper tank drain hoses at this same fitting using simple green. I used a 3/4" hole saw to drill a hole in the side of the hopper tanks so as to provide an easy way to clean them out completely. Once clean, we siliconed a 3/4" metal plug(HD/Lowes) in this hole. This provides access for future cleaning.

5) Evidently the previous owner used the rear ac the most, because its fan motor is wore out. It has a lot of side and end play, and it is noisy. PPL sells a fan motor kit for $120.

The ac system now blows 40 degree air on an 85 degree humid day.

We hope this helps

[breeder]

Quote:

Originally Posted by lonestarace Thanks for the input Ray & 007. Here is what we found and what we did about it. These units are Dometic DuoTherm Penguin heat pumps, #630215321. Remember, this is a 11 yr old coach and they're only new once: 1) The exterior ac shrouds needed replacing because they where cracked and brittle. $100ea at CW. We tape the new wx strip in place on the ac unit itself, then apply a bead of silicone to the wx strip, then put the shroud on, thus glueing the wx strip in its proper place to the shroud. The wx strip is inexpensive and can be purchaced @ HD or Lowes. 2) The air circulation system for the coach interior was dirty so it was decided to clean it as best we can. I replaced the insulation on the inside of the evaporator covers. They were dirty and falling apart. I used a non porous silver foil covered 1/4" thick bubble wrap type material that can be purchased in a large roll and is commonly used to make thermal barriers for MH windows. I vacuumed the faces of the evaporators, and their tanks, with the soft bristle brush vacuum cleaner attachment, then sprayed them w/simple green, and rinsed with fresh water by spraying the water thru the evaporators with a siphon type blow gun. Care has to be taken not to overflow the water into the interior of the coach. I used a towels up top and a large drip tray inside to prevent any accidents. The squirrel gage fans were dirty. I cleaned them by vacuuming with the soft bristle brush. This minimizes the amount of debris that falls down into the duct. We also removed the vent registers and played chimney swift in the air duct that runs the entire length of the coach. 3) We cleaned the condensers with simple green and a fresh water rinse from a garden hose. 4) Next we cleaned the condensation hopper tanks and drain lines. There is a t-fitting where the hopper tank drain hoses attach to the main drain hose that comes out the bottom of the coach. We disconnected the main drain hose at this t-fitting and blew a bleach/water solution down thru it. We blew out the hopper tank drain hoses at this same fitting using simple green. I used a 3/4" hole saw to drill a hole in the side of the hopper tanks so as to provide an easy way to clean them out completely. Once clean, we siliconed a 3/4" metal plug(HD/Lowes) in this hole. This provides access for future cleaning. 5) Evidently the previous owner used the rear ac the most, because its fan motor is wore out. It has a lot of side and end play, and it is noisy. PPL sells a fan motor kit for $120. The ac system now blows 40 degree air on an 85 degree humid day. We hope this helps

dont wanna rob this thread...but my 95national has 2 top ac's...the back one seems to cool well for a bit then kinna warm up ...but it is plugged into a 20 amp service, and the house lights were on..im just gettin into this thing [new guy] but i was wondering after i clean these, can a guy hisself charge these up? i have a good friend with an ag repair business and im havin him charge the dash ac, but need to know if its the same type of charging as the dash is, or does it take speci9al equiptment>???

[RV Wizard]

If it cools well for a time and then does not, it does not need charging of refrigerant but probably a good cleaning to correct the problem; most likely, freeze up. There are no charging port on the roof air conditioner and one would have to weld a service valve on to gain access into the system.

[lonestarace]

I believe the roof airs are more simular to a home unit than the dash unit. I think the DuoTherms use the same type of freon as a home unit, R22. Your dash unit uses R12 or R134. Like RVwizard said DuoTherms don't come with any service ports, but if u have a buddy that's a home ac service tech, maybe they'll be of some help?