Insulating behind cabinets in cab

[macnut]

The first year we owned our Adventurer, we drove in hot weather and after several hours our infotainment unit started malfunctioning.

It turned out the head unit was located behind the cabinets at top of the cab. The cabinets feel hot in the sun, and when you open them you can feel the heat radiating from in back of them. I thought it was the fiberglass cap, but that was insulated by Winnebago.

After researching here, I found that the top of the windshield, about 8 inches, directly behind the cabinets, is not insulated, exposing the cabinets and all they contain, to the sun and heat. What was Winnebago thinking?

Yesterday, I added insulation to the area. It was relatively easy, and took me about 90 minutes to complete. I took out the screws holding in the back of the cabinet, and lifted it up enough to move some insulation in place and tape it down. Here are a few before and after photos. I’ll let you know how it goes on our June trip.

Note that after Riverpark replaced our head unit, I kept it out of the compartment in the upper cabinet. I have it in the cabinet itself, since it is cooler, and also added a usb fan to provide air circulation.

 

[rk911]

we purchased a MagnaShade a couple of years ago which requires magnets be affixed to the interior side of the windshield. in order to do it right i had my shop remove the cabinets in the cab. while it was down i had them insulate the back of the cabinets. we were experiencing some of the same issues the OP was.

 

[macnut]

Good call, and great to hear it helped!

 

[creativepart]

As you know I did ours last summer. Makes a huge difference. Good going.

 

[macnut]

As you know I did ours last summer. Makes a huge difference. Good going.

Creativepart, I loved your solution and thanks for sharing. Great to hear it’s still working for you!

 

[Rossi6998]

Hi Al...

As you know the Sunstar 26HE has the same issue with the electronics in the overhead cabinet next to the windshield. Last year, I installed a fan in the cabinet door to help cool my satellite receiver. I still need to insulate, but the fan definitely helped (and I think it looks factory installed IMHO).

 

[creativepart]

John, when I did this job on mine I saw a couple of possible fixes that require less work. I didn’t see these possibilities before removing the cabinet interiors so I went ahead with the complete insulation job. But you might be interested in trying them.

The windshield itself isn’t so much the issue, it’s the black stripe painted on the back side of the top 10” of the glass. When I did mine, I thought it was the cap like Al mentioned but there is spray foam on the back of the cap that seems very effective. I used an instant read thermometer to test various surfaces and sitting in South Texas sun the windshield was pretty much outside temp, the back of the cap was cooler than outside and the black paint stripe was 40+ degrees hotter that the outside air.

So, here’s what might work to fix the heat.

The easiest why would be to apply a white band of vinyl to the outside of the windshield to cover the black stripe. I took a photo of the front of my coach and using photoshop experimented with how that would look and, I thought, it looked good.

The other way I thought this could be done is by using the small gap at the back of the windshield. If you sit on the dash and slide your back up to the windshield and look up you see a 1 - 2 inch gap. The back of the cabinets do not actually touch the glass. So it might be possible to slide a piece of foam insulation or even stuff some pink fiberglass batting up in the gap enough to block the heat from the black stripe.

Just an idea if you don’t want to tackle the bigger job of disassembling the upper cabinets.

 

[Rossi6998]

Interesting... Thank you! I will look into your recommendations. I always thought it was the cap (even though I knew it had the spray insulation). The one thing that bothers me about my MagneShade is it does not cover that black stripe on the windshield because I was not able to easily apply the magnets to the inside of the windshield to secure the shade over that black stripe. The company advised me of this prior to ordering the shade. I love the shade, but wishI could have it cover the entire windshield to further help keeping the heat out.

 

[jabass]

Another thought might be to have a solar shade placed on the outside to mitigate heat while parked.

 

[Japple55]

Creativepart and Macnut,
I need to do this also. What type of insulation did you use? I'm having my windshield replaced due to a crack and am thinking that would be the ideal time to add the insulation, if the glass guys will go along with the plan.

TIA,
Jim

 

[creativepart]

Jim, that will be the perfect time. I used pink fiberglass batting without any paper backing. I think it was about 5 or 6 inches thick. Without a windshield you can just lay a strip of batting across that whole area that’s exposed behind the cabinets when the windshield is removed.

Or maybe you could use some open cell foam or reflective insulation attached (glued) to the back of the black stripe on the new windshield beforehand.

I know the fiberglass stuff works for sure.

 

[macnut]

I went with this from Lowe’s. I thought it would be easy to work with, which it was.

I should also mention that I was able to get behind the cabinets by removing only 6 screws. I did not remove the wooden cabinets themselves, but just the carpet like material that is held in by the screws. It was a tight fit with my big hands (and because I’m all thumbs), but I managed without too much trouble. If I can do it, anyone can.

As far as results, I’ll Let you know after my next trip in the heat. CreativePart has already tested the results on his rig, so I’m confident I’ll get at least some improvement. He was my inspiration to tackle this.

I love John Rossi’s install of a fan in the cabinet door. I prop a door open a bit when on the road and that seems to get enough cool air inside the cabinet.

Hope this helps!
Al

 

[creativepart]

I love John Rossi’s install of a fan in the cabinet door. I prop a door open a bit when on the road and that seems to get enough cool air inside the cabinet.

I should add that after my pink batting was installed I removed the fan I had installed up there and no longer need to open the cabinet doors. The equipment in the cabinet makes more heat than is let in from the windshield. The problem is 100% solved.

 

[macnut]

Interesting... Thank you! I will look into your recommendations. I always thought it was the cap (even though I knew it had the spray insulation). The one thing that bothers me about my MagneShade is it does not cover that black stripe on the windshield because I was not able to easily apply the magnets to the inside of the windshield to secure the shade over that black stripe. The company advised me of this prior to ordering the shade. I love the shade, but wishI could have it cover the entire windshield to further help keeping the heat out.

John, if the back of the cabinet is not wood, but carpeted material, like mine, then you can access the very top of the glass pretty easily and attach the magnet there. Like I mentioned, the back and sides are held in by 6 screws. After removing them, I just lifted it out of the way (I did not remove it) and could access the inside of the windshield.

 

[Rossi6998]

Good to know. I will look into this further. Unfortunately, if I can access the top portion of the windshield to install the magnets, I will have to purchase a new MagneShade and provide them the new dimensions of the windshield. It's a good product, but expensive. I might be better off (cheaper) going with the reflective roll insulation you mentioned above. Thanks!

 

[macnut]

Ok, good luck with the mod! I’d love to hear how it goes.

 

[Japple55]

Job complete

Thought I'd show the final result. I had to add the insulation to the corners after the windshield was installed...they needed to get to the side bolts. MUCH cooler up there now. I used R19 and ripped the facing off.

 

[creativepart]

Perfect! Looks fantastic. Good job.

 

[Japple55]

Thanks, creativepart! It really helped quite a bit but I could still feel heat radiating from the overhead portion where WBO just sprayed on yellow foam. I stuffed a layer of the insulation up there in the open space above the cabinet wiring, just behind the panels that screw into the cabinet frame. It helped even more.

It's been 95+ degrees here in SW Florida today and the temperature in the cabinets is reading 96-104, depending on the surface I shoot with the IR gun. I don't have any previous readings to compare it to, but I know you couldn't touch metal in those cabinets. It is WAY cooler up there now, so I'm happy with the job, and my tech gear should be happier too!