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    • #3634
      MyPrevost
      Keymaster

      Hey everyone,

      I’m having an issue with my living room Dometic 15K Penguin A/C & heat pump. It’s leaking condensation into the bus after running for several hours. I’ve checked the drip tray under the condenser and cleared all the drain lines, so that doesn’t seem to be the problem.

      I’ve traced the issue to the return coolant line going back to the compressor. It originally had a sparse amount of black spray-on insulation to prevent temperature changes, but this insulation has become gooey and is falling off, causing excessive condensation on the line. This water then finds its way into the coach. It looks like Dometic relied on the insulation to prevent condensation, as there doesn’t appear to be a catch tray below the compressor or on this line.

      Has anyone encountered this before, or am I off track? If this is the issue, where can I find the spray-on black insulation that Dometic originally used?

      #3636
      MyPrevost
      Keymaster

      Is it possible that the evaporator is freezing up? When you run the unit, does the air flow decrease even though the fan speed remains unchanged? If so, try running the fan at maximum speed and see if it improves. Reduced air flow typically indicates that a small amount of freon has leaked out and is causing the freezing. To add freon, a technician needs to install a Schrader valve on the copper tubing and adjust the freon level accordingly. As far as I know, there aren’t any charts available for roof air units.

      #3637
      MyPrevost
      Keymaster

      Thanks for the input. The air remains cold and strong regardless of how long the unit runs, but condensation is leaking from the rear hold-down bolt. I removed the cover and noticed that the catch tray under the condenser is draining properly, but the low-pressure line to the compressor lacks a drip tray, and the insulation seems inadequate to prevent condensation on this tube. As a result, water drips into the floor of the AC unit and eventually makes its way down the hold-down bolts into the coach.

      I’m looking for feedback from the group on this issue and recommendations for spray insulation that can be used to address it.

      #3638
      MyPrevost
      Keymaster

      Gary,

      You have several options, but the most appropriate one is to insulate the line. You could also seal any possible entry points beneath the dripping suction line or fashion a drip tray with a drain to collect the condensate, but insulating the line seems the best solution.

      If you shut down the AC unit and let the line dry out, you might use foam sprays with care and proper masking, insulating tape wraps, or foam rubber pipe insulators secured with nylon wire ties. There could be other solutions as well.

      Since this issue is happening with one AC unit, it’s likely that the others might experience the same problem. Therefore, you should address the issue with the current unit and apply the same solution to the others.

      #3639
      MyPrevost
      Keymaster

      Gary,

      I recommend going with Jon’s suggestion: insulate the suction line from the evaporator outlet to the compressor inlet. The dripping is occurring because the line’s surface temperature is below the dew point. To stop the dripping, you need to both insulate the line and provide a vapor barrier to keep moisture away from it.

      Avoid using spray-on insulation, as it’s generally used in high-volume production and isn’t ideal for repairs. Spray-on insulation also provides only a marginal vapor barrier.

      Instead, look for roll insulation products at a refrigeration supply house. Do not use fiberglass insulation. Instead, use closed-cell foam insulation tape, such as Virginia KEMP part number 4E390. It’s around $17 at WW Grainger. The tape is approximately 2 inches wide and 1/8 inch thick with an adhesive backing. Wrap multiple layers around the line, and this should resolve your problem.

      #3640
      MyPrevost
      Keymaster

      NAPA also offers black A/C tape in their NAPA TEMP line, part number 209491. It measures 2 1/4 inches wide and 1/16 inch thick. The tape comes rolled up in a box, which might be more than you need, but it’s versatile. I’ve found it useful for various insulation and water protection needs.

      #3641
      MyPrevost
      Keymaster

      Gary,

      Find a Johnstone Supply or a refrigeration supply store in your area. Get some Armaflex pipe insulation along with a roll of Armaflex tape and Armaflex adhesive. When you cut the pipe insulation, use the glue to seal it back up. Any exposure to air can cause condensation to form. While I’m not familiar with the NAPA product, Armaflex is a professional-grade refrigerant pipe insulation that should work well for your needs.

      #3642
      MyPrevost
      Keymaster

      Good info guys. two thumbs up.

      #3643
      MyPrevost
      Keymaster

      Thanks, everyone. I’m beginning to think my issue might not just be a condensation problem. Yesterday, I noticed that the return line was icing up, and when the unit shut off, all that ice turned into water. I hadn’t seen this before, so I didn’t realize it was a symptom. Now I suspect that there might be some exhaust air mixing with the intake air. If that’s not the case, I’m considering that the unit might be beyond repair and might need replacing.

      I checked the part number for my unit (630515.321), and Dometic says it’s been updated to 651515.301, which is a 13.5K AC/heat pump ducted system compatible with the 5-button comfort control thermostat that I have. Does anyone know of a good vendor who sells these at a reasonable price?

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