Declaring war on Interstate summer heat gain

[wachuko]

hahahahahaha I saw the photo and reacted before reading your post!!! that is not your AI!!!! I was expecting it to be!!

Let me go back and read the post now... lol

[InterBlog]

It just goes to show you how *FRUSTRATED* people are with the lack of effective insulation in Class Bs generally, does it not??

[InterBlog]

People are already chuckling, so why not have a little fun with it, I thought:

[3bcamper]

Originally Posted by Hittenstiehl

That photo is too much[emoji876]

This is ultimately one must do to properly stave off solar heat gain. I was thinking of this approach, but had no idea where to find material of this dimension. Now that I know there is such a thing, this is what I will likely do if I find myself in hot, sunny conditions for an extended period. Thank you for sharing!

[rowiebowie]

This is what popped into my mind.

[InterBlog]

I was thinking more along the lines of this. People say the Interstate reminds them of the space shuttle. This isn't an Interstate, but it's close, so here we go.

LB_3 is going to say, "You are waaa-ay off-scale, girlie!" True, that. But it's just a meme.

[InterBlog]

I executed a mini-thermal-battle project yesterday, a new Insul-bright core covering for the Airstream signature window in the galley.

As it turns out, it is possible to sew Reflectix. And comical, too, as the sewing machine needle makes it go pop-pop-pop-pop just like if you were stomping on bubble wrap.


But why sew Reflectix at all?? Because I used the existing Reflectix window shield as a stiffener for this covering. The slider project is more like a drape - it doesn't need to stand up on its own. This one has to have some firmness to it to maintain its shape and stay in place.

One of the aspects I like best about the finished project is that it looks like an actual finished automotive product, not like a cheap fragment of Reflectix stuck on the wall (we Velcro the coverings adjacent to the windows that they fit, so they remain visible - see the comparison in the photo below, an original Reflectix and the new prototype).

Blog post here.

[InterBlog]

Some interesting continuing action over on that Class B Forum thread (here) which started out discussing RT insulation issues and then broadened into an account of general measures. Now there's a thread drift I can get on board with.

Greenhouse products were among the novel suggestions made for keeping a camper van cool, including this intriguing option called Aluminet.

[Boxster1971]

Check out the photos with this Amazon listing for a good sense of the folded bulk of Aluminet.
https://www.amazon.com/Agfabric-Refl...dp/B01N4QQ2KF/

[InterBlog]

One of my latest fixations: stick yer finger in them vent holes and feel around. There is not one lick of anything that could pass as insulation anywhere in there. There is nothing but two layers of bare metal.

I've long noticed that the rear doors are one of the main heat / cold offenders in the entire van. If the sun happens to be hitting them at an adverse angle, I can barely put my hand on the inner surface. At least in much of the rest of the van, Airstream made a token effort by putting some pink panther between the body and the inner finishes. Not so on the rear doors. And they represent a large surface area, so this matters.

Here's the predicament, though: the interior of the lower portion of the T1N rear doors is accessible because Airstream capitalized on the OEM cut-out to place two of its own webbed bins in those spaces. I could remove those, install some Thinsulate SM600L, and it would be an improvement.

The problem is, the top halves of the high-roof Sprinter doors are inaccessible to anything larger than a finger. I don't know how to insulate up there without causing potential problems such as air trapping which might lead to condensation.

Ideas? Other than giving this space the finger, of sorts. Keep in mind that we cannot cause an unacceptable air restriction that could lead to condensation. I would strongly hesitate on most spray products for this reason.

[Mansderm161]

Awesome photo

[Alex AVI]

Originally Posted by InterBlog

The owner says this approach works surprisingly well.
LOL

Putting aside the "My Favorite Martian" look, I actually agree with owner that his wrap approach would work. My only problem with it is, as anyone who has put a car cover on a car outdoors (does not matter whether car is clean or dirty), it is the fastest way to scratch up a car finish. However, in the spirit of the above AI owner's original idea, wouldn't a Justin Bieber chrome-wrap work as well? It may not have the same R-value but lots of solar reflectivity and almost 0% VLT ? It's attached to the body, doubles as paint protection, aerodynamic, and zero-setup time. The pic of van is that of a Mercedes Benz Vito van.

[Tobbun]

So the Texas heat has arrived. While not down in Houston, the DFW area is getting pretty hot as well.

We used the AI as a people mover this past weekend. Loaded up 9 people into it after starting the generator and running the roof AC. I had the MB AC going full blast and granted we were running a bit late (Highschool Graduation) but it didn't really ever seem to cool off. Prior to launch I had the windows open, the side door open and the canopy out to keep sun off that side. I really didn't get to run the AC for too long before loading everyone in. I closed all the windows/fan and kept the AC running with Generator on the 30 minute drive.

Once we got there (turned off engine to get side step out) and unloaded I went and parked. It was a full sun spot. I had planned on leaving the fan and opening the side windows but was having a fusion issue (wouldn't turn off) so hit the main disconnect switch and fusion went off. So I ended up leaving the AI closed up for about 2 hours. It got really hot. Outside temp was close to 100 with full sun 2pm -4pm.

Once we got done I went to get the AI... opened it all up... started the generator... started the Roof AC, started the MB Air. This time I left the fan open and two of the back windows... It seemed worse on the ride back.

Again, just short drives, fighting a uphill battle with the heat but all 9 were dressed up and a bit hot.

We have a long trip in a couple weeks (TX to AL) and I am thinking I will need to run the generator/roof ac for most of it during the day. I also read on here that it isn't good to have the MB AC full blast (can freeze up).

Any tips on keeping roof fan on/off, back windows cracked/closed/ all shades down, etc. for driving with these kinds of temps? Not really excited about keeping that generator running but don't see how anyone will be able to sit in the back without it powering the roof ac with this heat.

[rowiebowie]

Originally Posted by Tobbun

So the Texas heat has arrived. While not down in Houston, the DFW area is getting pretty hot as well.

We used the AI as a people mover this past weekend. Loaded up 9 people into it after starting the generator and running the roof AC. I had the MB AC going full blast and granted we were running a bit late (Highschool Graduation) but it didn't really ever seem to cool off. Prior to launch I had the windows open, the side door open and the canopy out to keep sun off that side. I really didn't get to run the AC for too long before loading everyone in. I closed all the windows/fan and kept the AC running with Generator on the 30 minute drive.

Once we got there (turned off engine to get side step out) and unloaded I went and parked. It was a full sun spot. I had planned on leaving the fan and opening the side windows but was having a fusion issue (wouldn't turn off) so hit the main disconnect switch and fusion went off. So I ended up leaving the AI closed up for about 2 hours. It got really hot. Outside temp was close to 100 with full sun 2pm -4pm.

Once we got done I went to get the AI... opened it all up... started the generator... started the Roof AC, started the MB Air. This time I left the fan open and two of the back windows... It seemed worse on the ride back.

Again, just short drives, fighting a uphill battle with the heat but all 9 were dressed up and a bit hot.

We have a long trip in a couple weeks (TX to AL) and I am thinking I will need to run the generator/roof ac for most of it during the day. I also read on here that it isn't good to have the MB AC full blast (can freeze up).

Any tips on keeping roof fan on/off, back windows cracked/closed/ all shades down, etc. for driving with these kinds of temps? Not really excited about keeping that generator running but don't see how anyone will be able to sit in the back without it powering the roof ac with this heat.

Seems to me like you did everything you could. Maybe you could have started the coach A/C a little sooner on the first leg. While I agree with your feeling about running the generator & A/C running for the two hours it was parked, you say you left it "closed up". I would always crack a couple of windows and leave the roof vent running with no qualms for that long. I should make a significant difference.


But what you and I are finding out is: There is heat, and there is Summer heat!

I got my Avenue last October and, following this thread, I've done many of the suggested mods to make the interior cooler. Added insulation, reflectix on windows, increased refrigerator ventilation, window tint,etc. We had some South Texas days in the 80's over the Winter and I noticed a good improvement. The biggest, was that with a few windows cracked and the Maxxfan running, the interior would stay only about 5 degrees above outside air temps. So much better than a car would do, I was feeling pretty good.

However, I had not yet owned my van during Summer and the increased daytime highs are proving quite another matter. I've lived here all my life and should have expected it, but the additional 15 degrees makes the word "comfortable" hard to obtain once you've sat closed up in the mid-day heat. And I'm probably ahead of most of you Interstate owners with my smaller size, less windows, and well-insulated fiberglass roof.

[gmillerok1]

As you found out, heat gain with all the black glass is incredible. In my 2011 lounge, I found that the bath wall would get hot enough to almost burn your hand. If they are still building them the same way, there is zero insulation behind that wall so it acts like the planet Venus and really gets hot. I originally added insulation behind there and Reflectix but it wasn't easy and because of the difficulty of accessing the area very well done; later, at JC, with the bath out for other reasons, I sealed off the window completely with Reflectix, and added full insulation and no longer have that issue. I did something similar on the other side as far as I could. I have a wardrobe model, the the interior would also get very hot. It no longer does so. In extreme summer environments, I would recommend Reflectix on all glass, including the windshield when parked, and drop the shades as well. It will not eliminate the heat gain, but it will help. The AC, which is the 13,500 btu Penguin II unit, cannot keep up with the heat gain, even with all that. It's livable, but barely. I'm replacing the 13,500btu unit for the 15,000bth with a soft start kit. I'm hoping that will help as well.

[gmillerok1]

Originally Posted by InterBlog

I feel compelled to cross-post this gem of a photo. It gets an A+ for originality.

This is not me. This is a poster on another forum who goes by the handle "classbbud". He used ten bucks worth of "space blankets" and clear packing tape to create this heat-rejecting enclosure for his van.

Despite all the other items already in my heat-war toolkit, I went ahead and ordered these blankets. It doesn't seem like it could be a lossy fall-back - for crying out loud, it's just ten bucks (Amazon: Leberna Emergency Foil Mylar Thermal Blankets 59 inches x 87 inches (Pack of 10) Double Sided Escape Tact Bivvy, Space Blankets Survival).

I think that if you use this material on the windows alone, it could make a big difference.

[jftompkins]

Originally Posted by Tobbun

So the Texas heat has arrived. While not down in Houston, the DFW area is getting pretty hot as well.

We used the AI as a people mover this past weekend. Loaded up 9 people into it after starting the generator and running the roof AC. I had the MB AC going full blast and granted we were running a bit late (Highschool Graduation) but it didn't really ever seem to cool off. Prior to launch I had the windows open, the side door open and the canopy out to keep sun off that side. I really didn't get to run the AC for too long before loading everyone in. I closed all the windows/fan and kept the AC running with Generator on the 30 minute drive.

Once we got there (turned off engine to get side step out) and unloaded I went and parked. It was a full sun spot. I had planned on leaving the fan and opening the side windows but was having a fusion issue (wouldn't turn off) so hit the main disconnect switch and fusion went off. So I ended up leaving the AI closed up for about 2 hours. It got really hot. Outside temp was close to 100 with full sun 2pm -4pm.

Once we got done I went to get the AI... opened it all up... started the generator... started the Roof AC, started the MB Air. This time I left the fan open and two of the back windows... It seemed worse on the ride back.

Again, just short drives, fighting a uphill battle with the heat but all 9 were dressed up and a bit hot.

We have a long trip in a couple weeks (TX to AL) and I am thinking I will need to run the generator/roof ac for most of it during the day. I also read on here that it isn't good to have the MB AC full blast (can freeze up).

Any tips on keeping roof fan on/off, back windows cracked/closed/ all shades down, etc. for driving with these kinds of temps? Not really excited about keeping that generator running but don't see how anyone will be able to sit in the back without it powering the roof ac with this heat.

I am not sure what the AS engineers assumed on their cooling load calcs; would say nine occupants (98.6 degF ea)... for both sensible and latent heat gains is part of it... and The AC needs to draw in outside fresh air (cool it) rather than recycle... to push all that human exhaust (CO2) out.... for a comfortable ride. So probably a number of things...

[gmillerok1]

Originally Posted by jftompkins

I am not sure what the AS engineers assumed on their cooling load calcs; would say nine occupants (98.6 degF ea)... for both sensible and latent heat gains is part of it... and The AC needs to draw in outside fresh air (cool it) rather than recycle... to push all that human exhaust (CO2) out.... for a comfortable ride. So probably a number of things...

Seriously? You think AS have engineers that actually do a heat load calculation? (no offense intended). More likely the question was "what will fit up on the roof that the genset can handle?" And even then the unit they picked was not recommended since Dometic recommends a 3.5kw genset unit for the 13,500btu AC, and it still isn't adequate to do the cooling.

[InterBlog]

This most recent string of posts is good inspiration for those of us who head north in the summer. Houston has been a bear this month - temps close to 100 degrees almost every day, one of the hottest Mays in recorded history.

Just to hit the pause button and inject a colder counterpoint, it was 41 degrees with a sustained 15 mph north wind (30 mph gusts) when I took this pic a few days ago in far northeastern Nova Scotia. Involuntary tears were streaming from my eyeballs as the frigid wind whipped them. Look at the grass in this pic - it has not even begun to get green yet. Three nights this week, there have been frost warnings here. I've survived many years in Houston by knowing that I will take regular breaks from its subtropical madness. So I come here for some subarctic madness instead.


This spot is on the other side of the massive lake that our little tract of land fronts on, more or less. It's a wilderness set-aside, analogous to a National Wildlife Refuge.

[Alex AVI]

Originally Posted by Tobbun

Any tips on keeping roof fan on/off, back windows cracked/closed/ all shades down, etc. for driving with these kinds of temps? Not really excited about keeping that generator running but don't see how anyone will be able to sit in the back without it powering the roof ac with this heat.

I have lived in Las Vegas the last +20 yrs and our summers here get very hot. Historical averages of over 102 degrees start mid-June and lasts to early-Sept. This gives me a good appreciation for what you are going through.

This is my first AI and during some of the mods I did, I have seen insulation batting on all panels I open next to any side wall. But it has major glass area that is tinted only with dark tint. No idea what it's TSER value is. My practice with our normal vehicles (sedans, trucks, & minivans) is to have all glass tinted with darkest & highest TSER on all rear windows. Same in front but staying 1 shade past legal tint, willing to take that risk since I am a careful driver. Even with windshield Crystalline or Llumar, still use reflection type inside-sun-shade.

In the AI, I close up day & night shades, front windows & windshield tinted w/ highest TSER I can find, use AI supplied sun shades, roof vent running, front windows slightly cracked, and bath vent open (not on). However, experience with my stick house windows prove it is way better to control sun infiltration before it hits glass rather than after. So will buy outside mounted windshield shade which wraps around to front sides.

Future considerations: If the big side windows and rear door windows were not so hard to re-tint due to valance & power shades, I would re-tint. But I have decided I won't go that far yet. There isn't an easy on/off & cheap & eye-pleasing product that I know of to put externally on our big/long side windows. So, I am considering a wrap package for the windows. Have an appt. with local shop that does major Vegas Strip casino work to see if a glass only wrap solution is feasible without looking tacky. The problem with this is as we also use our AI as a people mover, blocking the view is not desirable for my family.

Most hvac units are considered working efficiently when temp differential between air-return and vent output temps is in the 20 degree range. Expecting more than that is unrealistic unless major $$$ upgrades are invested. Also, BTU-overkill is not a golden bullet. A unit with too few BTUs may not be able to cool a large space efficiently, while an oversized air conditioner in a small space will cycle on and off, wasting energy and decreasing the unit's ability to adequately dehumidify the room. Only upsize your A/C after doing adequate calculations, preferably by an rv hvac expert (not me ).

I personally think it is constantly an uphill battle during summer months, I never get ahead in LV even after driving 2 hrs. Lucky to get a 15 degree drop when outside temp is 115. This is not just an AI issue, it's the place we choose to live in. I bet the AI owners living in Chicago (my hometown) probably has the same issue, only with their interior not getting warm enough. So on top of above strategies, I will just repeat this mantra as our LV summer approaches - "tanks are usable, tanks not frozen, repeat" .