I was so pleased with the results I got from plugging the hidden air gaps around my engine lid and closet, that I decided to investigate my entire AC/Heat Pump Basement System. (This is something I bet most of us have never done.) And in my case, I made some interesting discoveries and came up with some stellar improvements I would like to share with you. (Hopefully, pictures will show up below.)
1) Remove the right-rear brake tail light and checkout the fully exposed air duct from Winnebago. Then look underneath your coach, and inside your engine compartment. What I saw was a lot of air and very little insulation. So I decided to do something about that!
Plus, my air duct was leaking cold air (and heat in that mode) into the engine compartment where the tape seams were starting to come apart! Plus I found condensation dripping from the lose seams caused by a temperature differential; i.e., where the leaking cold air was coming in contact with hot ambient air.
I especially was not fond of seeing water dripping from the bottom of the air chamber that undoubtedly was forming inside the air duct too, because that's where mold likes to grow!!!
Solution: I used a long bristle brush and finer large paint brush to wash the dirt off the outside of air duct as best I could. Then I applied 3 rolls of waterproof HVAC-Butyl-Aluminum Tape to completely reinforced the entire air duct below and as far up the air duct (into rear cap area) as I could reach. This alone would probably be enough, but not for my coach! ...Plus I was also concerned about the heat transfer from the Aluminum tap, and I did not like the minimal insulation job the factory did...
So I decided to close off the gaps by spraying Great Stuff "Big Gap" Foam (rated to 240F) into that area to add insulation to the bottom air duct portion as seen from the engine bay.
Applying some of the foam first to the sides, so that it would stick and harden first; I then followed with more 3 cans of foam. ...And I used my hands to push the foam back in place after the foam was 3/4 dry and not too sticky. (I liked what I saw, but not the looks of home improvement project.)
I decided to go one step further and paint everything black with Flex Seal-Black!!! This turned out to be a good decision. As not only did the Flex Seal added another protective layer, it also sealed-off the seams of the HVAC tape so I know they will never pull apart later, and the black Flex Seal made everything look great like it came from Winnebago. (Winnebago, are you listening?)
I'm so happy! It was 95 degrees outside today and the inside of my RV cooled down much faster than before!
Note: I also recommend using an oscillating desk fan to recirculate the air and push the air to the back of the coach for even faster cooling!
2) Now for the part I am most proud of: I cut one of the water cooler insulating blankets to 24" wide and used a broom to shove it up the air shaft to close the gap between the coach end-cap and the air duct. So going through the brake light opening, there was enough room to shove the insulation blanket 4 feet up and then tuck it 2 feet down the shaft using a broom.
And because the insulation make a tight fit, I don't expect it to fall. Then I insulated the brake light perimeter with weather stripping to make sure no water leaked in. This concludes all the outside insulation improvements.
3) Now, back to the inside insulation improvements: I never liked how I could feel a cold penetrate the coach when I was asleep. And I never could figure out where the cold was coming in either. I just concluded that RVs are fair weather rides at best.
But now that I got a taste of how insulation can make things more comfortable inside my RV, I decided to insulate under the bed. And since Walmart was closing out on their water heater blankets for only $5/roll (regularly $25/roll) I decided to by 5 rolls and insulate the **** out of my entire bedroom area. (Excuse my french.)
This includes the hidden compartment in the closet and more on top of the engine lid; and I added 2 layers of insulation under the bed! (Taking care not to seal off the Select Comfort bed air pump inlet and cutting the insulation to fit around the cables and wires... leaving plenty of air gap around the circuit panels.) And I even cut a 2 strips of insulation to go under the bottom dresser drawers... where I found 2 large holes that leaked air to the outside.
NOW the temperatures in my bedroom are more comfortable! And I'm sure I will not feel the outside cold (in the range of 20-40F) like I use to at night. Not to mention, I don't expect the night heater will not come on as often.
Note: I prefer to use a portable electric heater to run off the incoming 120v line vs. running the heat pump, as this should extend the life of the heat pump too! Besides, the heat pump is a better AC unit than it is a room heater.
Hopefully these pictures will help you see how and where I used these perfectly sized water heater blankets to improve efficiency of my AC/Heat Pump; and I strongly suggest you do the same if you plan on facing below 50F or above 90F weather. Good luck!
Air Intake Area Under Washer/Dryer (Plus a good spot to locate a solar controller when you decide to add 4-100W to your roof.)
Under Bed:
Under Dresser:
Behind Tail Light:
Tape Bottom Air Box from under the RV:
Fill in gap with Great Stuff "Big Gap Foam"
Spray Everything with Flex Seal-Black
Linear Mode
