Originally Posted by mstell2
What are you trying to achieve with this modification?
Sent from my iPhone using Forest River Forums
Sorry I have been a bit busy and have not had time to answer.
Someone on the forum a while ago was up on the roof of his RV working on the air conditioner and noticed the air handler was ice cold. He thought that meant he was losing cold air through the cracks and crevasses of the loosely screwed together air handler. His solution was to metal tape all the corners to seal the unit air handler and then he glued Mylar insulation to all the flat surfaces to keep the cold air in and the hot air out. I agree and his (and my) mod allowed my unit to function flawlessly in the Texas 115 plus heat.
As to insulating the large compressor pipe:
"The large, cold, low pressure line, carrying the evaporated refrigerant from the air handler, should be insulated to prevent condensation. The small, warm, high pressure line, carrying condensed refrigerant into the air handler, should not be insulated. I am not an air conditioning professional so your mileage may vary.
Explanation: The unit outside the house compresses the refrigerant from the large line. This makes the refrigerant very hot. Then the refrigerant is run through the condenser coils and the fan blows outside air over them to remove the heat and condense the refrigerant back to liquid. The small line now carries the warm liquid refrigerant back into the house. No insulation is needed on this line because it is still warmer than the outside air. If the air cools it some more, that only helps. In the house, the pressurized liquid refrigerant is allowed to rapidly decompress in the evaporator coil. The instant drop in pressure causes an instant drop in temperature, making the evaporator coil very cold. Interior air is blown over this coil, cooling the air and warming the coil and refrigerant. The evaporated refrigerant, which is still rather cold, now flows out of the house in the large pipe. It does not help us for this refrigerant to get warmer after it leaves the evaporator coils. It just makes it harder to compress and cool in the condenser coils. So we want to prevent condensation on this pipe. That is the reason for the insulation. "