azdryheat wrote:
Remove your ducted AC and look inside the 'hole' in the roof. We had a problem with our Voltage. Whoever metal taped the interior of the hole failed to vacuum out the sawdust. What happened is the metal tape rolled itself up into a ball and much of the air was lost into the ceiling rather than going through the ducts. I removed all the tape, cleaned out the hole, and re-taped. It mad a decided increase in the airflow. Another item was the two intake vents in the ceiling. The openings were closing down and I put a piece of PVC pipe in there to hold the intake open. Now the ducted AC moves a lot of air.
After I removed the shroud, I did check out the ductwork the best I could. Even used an inspection camera with a 2-3 ft. sensor in the shroud area and on each duct. My longest ductwork run is approx. 10 ft., so obviously not a conclusive check.
In any case, a/c ductwork design, IMO, is very similar to all the stories you hear about improper factory RV frig installations. Sometimes RV manufacturers follow proper installation standards, sometimes they don't.
You may have found an obstruction, removed it, and improved your air flow. However, if you're one of those unlucky owners where the manufacturer did not follow proper installation standards (specifically, incorrectly sized ductwork), you may still be surprised to see what your a/c unit is capable of by by-passing the ductwork.
IMO, for some, removing the shroud is a low-risk, simple test that may be worth trying.
