Discussion: Some general insulation and temperature observations

SouthernNights

Past South Carolina Chapter Leader
We have been camping for the last few days with these 100+ temperatures with out any shade.

Subject:
2012 Mesa , does not have the new whisper quiet A/C. It does have the second air in the bedroom, dual pane windows , Yeti package, full body paint and no slide toppers.

Sitting in full sun with the temps at 95 degrees by 10am the inside of the coach starts loosing its battle with the temps. It will start the morning at 72 degrees on the inside.

Here are some observations I have made.
Stock registers.
Temp at first registers from rear A/C - 53.9 F.
At last registers- about 59 F. I do not have an anemometer but there is good air flow by the unit and drops off significantly by the last register. It does have the tent mod in the L/R unit which did improve the flow somewhat.

Inside wall temps range from 91F where the outside of the wall is in full sun to high 80s where the outside of the wall is in the shade-or at least no sun.
Surprisingly enough the ceilings of the slides are not that much different than the walls. I thought for sure they would be well over 100F with no toppers.

Outside temperatures:
This is where I was surprised. I knew the body paint would act as a heat sink. And as pretty as the body paint is, I never would have gotten it if it actually cost more than the other Landmarks. I would have been cheap just taken white with vinyl graphics-and probably would have pulled have the vinyls off. But that is a different story...

In the sun:
Light bronze or gold about 119F
Medium color brown 125F
Dark brown over 133F.. Thank goodness there is not much off that on the sides.

In the shade or at least off-sun exterior temps all ran a little more than ambient temperatures to +10 degrees.

The inside front and rear caps have the greatest temp difference. A tribute to the Relectix???


Results: By mid afternoon the inside temp of the trailer is about 84F downstairs but the upstairs is still around 73F. Considering the outside temps. I would say the 30-40 degree drop in temperature between exterior and interior is acceptable. I do belive there are better products that could be used rather the white extruded polystyrene.



For the most part after talking with several other owners I guess it is what to be expected. I am not complaining because once the ambient temps drop down to 95F the trailer can keep up fairly well.

It has made me think a little about the duct work in the trailer. The worst shape for air to flow through is a rectangle or square. Air flow does not like 90 degree corners.

I also think there is potential for the airflow to be much better at the registers. There is enough room with in most of the existing duct to run round duct. The problem there is not enough room to incorporate the registers with the round duct.

I also think that a lot of volume is lost when the air comes out of the airbox on either side and has to split front to back. I am thinking something similar to the tent to help make it's split might improve airflow a little.
 

danemayer

Well-known member
All sounds familiar. Direct sun on either side seems to be the biggest problem. I may spring for window awnings to turn off the sun a bit.
 

Rickhansen

Well-known member
Larry,
All very good observations and documentation. I am surprised that our '09 3670RL without dual pane windows exhibits the exact same end result. We're good to 95 degrees outside in full sun, and then we start creeping up about 1:1 with increasing outside temps. I've tried different strategies to extend it a bit without any real result. This has mostly been to "pre-cool" the rig early in the morning to get excess humidity out. My next step is to put a small fan in the side aisle to help shift some load to the bedroom A/C. Thanks for sharing this info.
 

SouthernNights

Past South Carolina Chapter Leader
Dan, window awnings are in our future also. Had them on the BC. and they worked well. Rick, started with the fan in the aisle on this trip. I do like the dual pane for condensation and noise but I dont think you are missimg a thing being without them in the heat. Temps on the inside of the windows were higher than wall temps. When we get home I am going to get a cheap anemometer and play around with the duct work. I really feel like the potential is there for a much better flow.
 

rick_debbie_gallant

Well-known member
Dan, window awnings are in our future also. Had them on the BC. and they worked well. Rick, started with the fan in the aisle on this trip. I do like the dual pane for condensation and noise but I dont think you are missimg a thing being without them in the heat. Temps on the inside of the windows were higher than wall temps. When we get home I am going to get a cheap anemometer and play around with the duct work. I really feel like the potential is there for a much better flow.

Larry, what about reflextex or whatever it is called on the outside of the glass? And as far as that goes the slide-outs would not hurt by having the same stuff on the outside of them also.

Also, if you have an I phone there is a wind-speed app that you can get. It works by the wind or air blowing across the mic.
 

TXBobcat

Fulltime
2008 3400RE Bighorn. Orig 15k in livingroom and new 15k in bedroom.

Temp in Richmond IL.jpg


20% differential is pretty good. To help when this hot we use a large fan on the floor in the livingroom.

BC
 

JJOren

Well-known member
You know, I guess I make things too simplistic. I'm sitting very nicely cooled in our 2012 MESA in this heat and direct sun with no shade. In this kind of extreme heat we turn on both air units, open the major vent on the unit in the living room, turn the fans on manual and turn on the ceiling fan. Temp stays very comfortable inside in both the living room and bedroom, regardless of the temp outside.
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
We were in Amarillo a few weeks ago with temps in the 100s daily. What I found was running both units early to get it almost too cool helped stay ahead of the heat. We run the ceiling fan, keep the shades closed, and also have a Vornado "whole-room" fan on the floor in the living area, pointed at a 45 degree angle upwards. I swear by this little fan! It really moves the air and you can feel cool breeze nearly anywhere you sit.

This does make me think twice about the full body paint on my 'next' coach. ;-)

Erika
 

Manzan

Well-known member
Question: Has anyone tried using a small fan inside the register to pull more cold air from the AC? Have not had a problem this far but have not been in anywhere near that much heat.
 

hoefler

Well-known member
One trip we made to Tunica, Ms., it was 108* out, full sun, and asphalt every where. With the main unit set at 75* and the bedroom unit set at 78*, a fan set at the top of the stairs blowing into the main living area, both units cycled regularly. A thermometer sitting in the back of the rig on the desk was reading 76*-78* depending whether or not the A/C was running. We have slide awnings and had the big awning out. Don't have dual pane windows either. And we have an Antique 06 Landmark Mt. Rushmore. We never turn the A/C up, matter of fact, we turn the main unit down to 72* down at night. We have been very happy with the way the rig handles the heat.
 

Ray LeTourneau

Senior Member - Past Moderator
Larry, one of the things that helped us was to use aluminum flashing tape at the last register in each run of the ducts. We used the tape to divert the air flow down into the room instead of letting it flow past the register to the end of the duct.
We also use a small fan on the floor of the bedroom blowing towards the lower level. I used the logic that the bedroom floor would be the coolest area so we try to use some of that air by blowing it into the lower level.
Unless the outside temps reach 95 or so, we get by on the main A/C. The bedroom unit rarely gets used.
 

kakampers

Past Heartland Ambassador
We have changed the tiny little ceiling fan to a 52" residential fan. Added a screen over the rear picture window and awnings over the windows in the main slide....we have been able to keep the inside a comfortable 78 degrees with the temp at 105 outside. We also have dual airs and dual pane windows.
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
We have changed the tiny little ceiling fan to a 52" residential fan. Added a screen over the rear picture window and awnings over the windows in the main slide....we have been able to keep the inside a comfortable 78 degrees with the temp at 105 outside. We also have dual airs and dual pane windows.

Can you post a picture of your fan? I've often wondered about that but thought it wouldn't fit.

E
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
Has anyone used the UV blocking fabric that snaps on over your windows, like this? We met some folks in Arizona one time, that swore by it.

E
 

TandT

Founding Utah Chapter Leaders-Retired
Has anyone used the UV blocking fabric that snaps on over your windows, like this? We met some folks in Arizona one time, that swore by it.

E

Erika,
Yes, we have a similar product on the large rear window and it works very well. Keeps the rig noticeably cooler.
We opted for a beige color to match the rig, but if I were ever to order another piece of the fabric, I think I might try the dark charcoal color.
I know, it sounds hot being a dark color, but I believe it is sort of a paradox. The dark color lets less light in, therefore keeping it cooler inside. IMHO.

We opted for the stainless turn buckles instead of the snaps. Very easy to get on and off.
Trace
 
Last edited:

jbeletti

Well-known member
Erika,

We have 2 for the door side windows and 1 for the back window. Ours are perforated vinyl from Prompt RV Screens. Not sure if that's similar to the product in your link our not. It REALLY helps in direct sunlight. In use them maybe every 4 setups or so.
 

hoefler

Well-known member
Also get the square foam blocks for the vents, they make a world of difference since the vents are uninsulated with only a thin piece of plastic to block out the heat.
 

2psnapod2

Texas-South Chapter Leaders-Retired
With the heat in South Central Alabama, We stay very cool with just a small fan on the floor. Kelly even raises the temp on the Main AC and Lowers the temp on the BR one during the day to lower the noise. We have DP windows and no covers for the windows. If you do get up to do anything in the way of labor tho it does tend to be a little warm. But its working out for us.
 
Top