UPDATE - DW and I have been pleased with the added insulation to our A/C units. It really has helped keeping our Monty cooler without a doubt.
Watch for another A/C mod post in the coming weeks. This mod made a bigger change in cooling and increased air flow!
Decided the other day to take a closer look into our A/C cooling issues. I did this to my unit and a friend of mine on this forum, also a 2014 Montana. I already went through my ducts and pulled them apart to see if they needed to be trimmed down to be flush with the actual ducting in the ceiling as written up by others. I was surprised to find my vent covers were only sticking up into the duct by a 1/8”, unlike others have posted being an inch into the duct. Maybe it has something to do with the newer build dates. Mine was built in August of 2013.
Any way I headed to the roof. I removed the top cover of the rear A/C unit first, and then removed the 8 screws that covers the evaporator. Look at the pictures below. He’s your saw dust Keystone! Remember, that 2 images are my unit and the other 2 are my friends.
We brought up a vacuum to remove the saw dust and cleaned the evaporator as well. We repeated this for the front A/C unit too. We found no saw dust in the front unit. We put everything back together and added extra insulation around the evaporators using foil tape NOT DUCT TAPE to secure everything together, in both units as you can see in the last photo.
Before doing any of the above work we took vent temps using my IR in both of our units. Our units had been running all day and both units were in the sun. There was only a 2-3 degree difference between our units. Those temps read around 52-55 degrees. After adding the insulation our temps dropped down by 6 degrees to around 46-49 degrees at the vents.
Another interesting find was if you had the rear A/C running and the front running on fan only, the duct temps showed a 20 degree difference from reading the rear ducts and working my way forward to the front ducts.
If I kept the rear A/C unit running and turned off the front unit (no Fan or A/C), then there was only a 6-7 degree difference. Reading the rear A/C ducts closest to the evaporator I would get that 46-49 degree temps. The readings would get warmer as I went to the front.
In closing to get the maximum out of your units, they must both be running on A/C mode. The duct readings only varied by 2-3 degrees this way. Hope this helps...
Below you can see the saw dust on top of the evaporator and at the base of the unit. There's no telling how much was in the evaporator fins.
Below added extra insulation on both A/C units.
Threaded Mode
