Poor insulation? A/C can't keep up.

[Foothiller]

We have many experiences in the West where our two A/C's can't maintain a 78 degree temperature. The solar heat load is generally very high out here, that combined with high air temps our rig is often challenged. Twenty years ago our Carriage rig did fine with one A/C, but we may have avoided the hotter areas. Here's what we've done to get things under control with outside air temps in the high 90's:
* Reflectix between the BLACK shades and the windows (black may look cool, but is a terrible choice as it absorbs heat and transfers it to the interior).
* Insulation pads in both ceiling vent openings.
* Run both A/Cs with the bedroom set to 72. The main A/C came with airflow installed, air dump is closed.
* Both A/Cs (Coleman 15 and a 13.5)have a decent in-to-out temperature differential based on the Coleman specs.
* 12" fan blowing air from the bedroom towards the great room.
* If the trailer has gotten hot during travel, we leave one popout in, both if possible.
Over 100 degrees, the rig just gets hot. We've left the rig and stayed in a motel at times.

The specs on our rig claim decent insulation (R30 main floor, R40 roof, R9 walls). Some wall portions are not insulated: the back of the front and rear high cabinets get very hot. There are lots of windows which are at best R1 and I'm guessing the the popout roof/floor are at best R9.

I think that I'd need a lot of propane to sit out a blizzard in this rig.

Any ideas?

 

[jkwilson]

If it’s not windy, your awning can be a big help to keep the sun from heating the side of the trailer.

Tops of the slides are particularly bad about heating things up as they aren’t insulated. Slide toppers will shade them, or just a piece of foil backed foam insulation sitting on top can be a big help.

Your furnace air return is a direct path to the basement and can be a source of heat. Block it off when using AC. I don’t know specifically where yours is, but it’s in the toe kick for the hutch in other rigs with similar floor plans.

Air conditioner assembly can leave something to be desired. Take the faceplate off and make sure nothing is restricting air from flowing where it is supposed to go and nothing is open to let it go where it shouldn’t.

 

[Foothiller]

Thanks JK.

We do use the awnings whenever we can - the shade makes a difference. The furnace return is a good pointer - toe kick under the "coffee bar." I looked at putting toppers on, but there didn't seem to be enough room to mount them on the sidewall before the roof starts - there's a gutter there. When we're back in our semi-permanent spot I'll try to insulate the tops of the slides.

 

[geotex1]

At peak performance, campers only cool to about 20 deg below ambient temp. Put the RV Airflow in the forward unit too and keep its thermostat a few degrees cooler. Make sure all interior room doors are open, closet closed, and all basement storage closed. When it's going to be a roaster, bring the inside temperature down, way down overnight. Break out the blankets if you need so that you have that "reserve." All ingress and egress needs to be quick and efficient.

 

[el Rojo]

Install the RV Airflow system. These will keep cool air from escaping to the outside. If you have a dump option (for air) on your AC you don't have them.

Red

 

[OurNewEra]

Thanks JK.

We do use the awnings whenever we can - the shade makes a difference. The furnace return is a good pointer - toe kick under the "coffee bar." I looked at putting toppers on, but there didn't seem to be enough room to mount them on the sidewall before the roof starts - there's a gutter there. When we're back in our semi-permanent spot I'll try to insulate the tops of the slides.

As for toppers . . . if you installed them the rain gutter could be replaced with the track for the topper connection to the side wall. If you have a topper you don't need a gutter above the slide. Or if you wanted a bit more slope the topper track could be installed above the gutter. I can attest that you do get a good bit of heat through the top of the slide. Our pantry gets hot enough that we have to be careful what we store on the top shelf, paper products only.

I'm sure there are other Reflection owners that have had slide toppers installed.

 

[Foothiller]

As for toppers . . . if you installed them the rain gutter could be replaced with the track for the topper connection to the side wall. If you have a topper you don't need a gutter above the slide. Or if you wanted a bit more slope the topper track could be installed above the gutter. I can attest that you do get a good bit of heat through the top of the slide. Our pantry gets hot enough that we have to be careful what we store on the top shelf, paper products only.

I'm sure there are other Reflection owners that have had slide toppers installed.

There's not enough room above the gutter, but maybe replacing the gutter is an option that wouldn't look trashy. That's more installation work than I would take on. If I could find somebody willing and competent to do it, I'd probably sign up. Of course we're on a five month journey so any work is complicated. It'd be nice to hear from a 295RL owner who has done it.

I figure that, at best, the slide roof is R9. I'll have to use my IR thermometer to map temperatures in various spots when I get back to the heat. We're on the cool Pacific coast for a while.

 

[Foothiller]

At peak performance, campers only cool to about 20 deg below ambient temp. Put the RV Airflow in the forward unit too and keep its thermostat a few degrees cooler. Make sure all interior room doors are open, closet closed, and all basement storage closed. When it's going to be a roaster, bring the inside temperature down, way down overnight. Break out the blankets if you need so that you have that "reserve." All ingress and egress needs to be quick and efficient.

20 degrees is really problematic. The A/C does get a 20 degree drop between return and supply but if the rig is going to "leak" 15k+13.5k BTUs, then we're stuck. Areas all around the west are getting heat spells with high temps 105 and above. We do most of what you said. The bedroom unit cools really well because of the small space even though some of its air goes to the great room through the ducts; dump is closed, the unit just feeds the ducts and I don't see a cavity where airflow would go.

The major problem occurs when we move: hours in the heat warms up the trailer and on a hot day it cannot recover. Traveling early is a fine idea, but many parks have a 1pm check-in. A generator would help, but we couldn't handle the extra weight. Oh well.

 

[OurNewEra]

There's not enough room above the gutter, but maybe replacing the gutter is an option that wouldn't look trashy. That's more installation work than I would take on. If I could find somebody willing and competent to do it, I'd probably sign up. Of course we're on a five month journey so any work is complicated. It'd be nice to hear from a 295RL owner who has done it.

I figure that, at best, the slide roof is R9. I'll have to use my IR thermometer to map temperatures in various spots when I get back to the heat. We're on the cool Pacific coast for a while.

Use your 5 month journey to head east, east, east. We left Calif in 1997 and have never looked back! At least in Florida a real feel over 100 is NORMAL and expected. Good luck with the cooling. As others have said 20 degree differential is optimum and a comfortable indoor temperature may not be attainable with the current outdoor weather.

 

[jkwilson]

20 degrees is really problematic. The A/C does get a 20 degree drop between return and supply but if the rig is going to "leak" 15k+13.5k BTUs, then we're stuck. Areas all around the west are getting heat spells with high temps 105 and above. We do most of what you said. The bedroom unit cools really well because of the small space even though some of its air goes to the great room through the ducts; dump is closed, the unit just feeds the ducts and I don't see a cavity where airflow would go.

The major problem occurs when we move: hours in the heat warms up the trailer and on a hot day it cannot recover. Traveling early is a fine idea, but many parks have a 1pm check-in. A generator would help, but we couldn't handle the extra weight. Oh well.

Do you have vent covers to let you travel with vents open? Might help some.

 

[OurNewEra]

Do you have vent covers to let you travel with vents open? Might help some.

[MENTION=34860]Foothiller[/MENTION] I will second what [MENTION=10506]jkwilson[/MENTION] said about vent covers. A few months back I installed the black Maxxair covers on our two vents, not smoke or white but the black. I selected the black primarily so it matched the other roof items and not even thinking about sunlight or heat. They significantly reduce the interior heat. Sunlight does not come through the black Maxxair covers. You said you have the insulation pillows in the vents but the black covers may help also.

 

[Foothiller]

I have vent covers, but it's usually hotter outside than inside, so I leave them closed.

I too left CA in 1997, for a 2 year full-timing trip. We spent that winter in FL, but we just don't do well with humidity. I'm looking forward to getting back to our White Mountain site in AZ, but we have to cross hot country to get there (we're doing CA/OR coast now where it's quite cool). We'll just have to deal with the heat we encounter and whatever the A/Cs can do.

 

[traveldawg]

We've been all over the west this year, TX, AZ,NM, NV, CA, OR and it has been the hottest weather we've ever been in. When we have good power and can keep both ACs running we stay comfortable. When in Las Vegas at 104 degrees it was bad as the campground power was terrible. We had days where the inside temps got to 84 degrees.

So I think good power is essential.

We've been in Bend, OR for the last few weeks and have had days over 100 degrees ( I can say the same for Joshua Tree; Lake Havasu; Baker, NV; Carson City and more). The almost never got over 79 degrees. I run the living area AC at 77 or 76 degrees, Auto, HI and the bedroom air at 76 or 75 degrees, auto, hi.

Travel days does require serious cooling down but most travel days are 4 hours or less to it isn't too crazy getting it cool again.

I made my own air deflection plenum mod for the main AC (it's on this site under my mod list) but didn't do anything with the bedroom air.

I have swapped around some of the directional ducts and the ones that are just a 45 degree angle in 2 opposite directions to get air flow we like. I have found the main AC will short cycle if I am the duct nearest my door to much toward the thermostat.

I have black vent covers and a thermal vent pillow in the shower skylight (but it only covers 2/3s of the skylight. We keep the shades (beige) down on the sunny sides of the RV and try to keep the awnings out to shade the side when possible. We don't have slide toppers. I tried the fan routine but it never seemed to help unless we sat in front of the fan; we haven't bothered using it lately.

In 30+ years of camping we have never had so much heat. We live in FL and have traveled comfortably there in summers (but the temps is usually 95 or less). This is just bizarre heat this year. Tomorrow we start working our way toward the Olympic Peninsula and cooler temps - so looking forward to that.

 

[openrangeowners]

We just returned from a cross-country trip where the hottest temps were at Big Bend Texas. The 50 amp receptacle was not working correctly so we had to use 30 amps until it could be repaired. We were essentially on a blacktop parking lot (Rio Grande Village) with no tree cover. It was 103 degrees one day. We have 2 dogs that stay in the camper when we are out, so I have a 3K inverter with 400 amp hours of lithium battery (can run one AC for 3-4 hours (more with sunlight on the solar) .... when we left in the morning the camper was 74 degrees including the bedroom (running 1 AC). When we returned in the afternoon the camper was 78 degrees except the bedroom and bathroom were 95 degrees (doors were closed to them). I added a shade on the skylight in the kitchen (yes we have a skylight and a separate ceiling vent that has a smoke colored cover). The bathroom and the front bedroom windshield window were heating up the that part of the camper - the bathroom skylight did not have a shade (the vent does though). I could feel the heat coming in through the skylight into the shower .... I have since ordered a removable insulated 14" x 22" insert for that.

When we were able to hook up to 50 amps, the bedroom and rest of camper cooled down to 75 degrees where we had set the thermostats - and fairly quickly given it was 103 degrees outside sitting in full sunlight on an asphalt surface.

When we travel, I normally remotely turn on the bedroom AC about an hour before we arrive (using inverter/battery) and the camper is definitely in the upper 70's to low 80's at that point when the outside temp is over 90 degrees.

 

[Foothiller]

Thanks Traveldawg and openrangeowners. I looked at the specs for a Solitude recently and the insulation was a bit better than my Reflections 150 series. I'm pretty much maxed out on weight, so really can't do solar or generator - they're a nice solution to travel heat. I also try to limit travel to 4 hours except when I'm trying to get through a area like NV.

I use two skylight insulation pillows in my 13x28 shower skylight, they've stayed up there so far. I will tweak the A/C vent directions a bit.

So far we've had good 50A power, it'd be nice if that continues. I'm actually using heaters here on the coast and have popped the 30A breaker twice.

Indeed, the "heat dome" action seems to be making this a monstrously hot summer in the west. More than normal wind too, I think. If I remember my A/C stuff from 50+ years ago, handling 95 degree humid air is more difficult than 95 degree dry air.

 

[tonygoncalves]

What's your battery and inverter situation? As with openrangeowners, I have a 3000W inverter that runs all the 120v in my 30A trailer, and will last about 5 hours on my lithiums.
That could be something to look into, to cool your trailer while driving? Depending on your battery setup, you could turn it on an hour before arriving, and it should be enough to cool your trailer without killing your batteries too much.
Also, take a look at your AC condenser, fins, and grill up on the roof. Make sure they're clean and free from dirt, cobwebs, etc. Anything on them blocks heat transfer and airflow, which reduces AC efficiency.

 

[Linndoren]

I too have this issue in Texas. This is what I have been looking into.
https://www.shaderv.com/

 

[Foothiller]

I haven't been to a CAT scale recently, but I don't think that I have spare weight capacity to add solar and multiple batteries. A good idea if you can handle the weight.

The shaderv thing looks very interesting for long in-place stays. Keeping the sun's rays off should eliminate a lot of heat load. Thanks.

 

[A.Texas.Yankee]

Do you run your exhaust fans at all? I know, oddly enough, that running the maxxair during peak hours really helps suck out the high heat at times.

Newly full timing in our 2021 Momentum 395MS-R with our tow pig being a 2021 F-450 KR

 

[J Maguire]

Just returned from a 5 week trip through AZ, Utah, Idaho, Oregon, Montana and Washington State at the hottest period of weather with a similar rig. I recommend upgrading the 13.5k to the 15k... we had no problems with the heat having two 15k units. Cozy.