Reflectix Experiment with Interior Trailer temps

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

butchiiii

Well-known member
Joined
Sep 8, 2014
Posts
347
Location
Los Angeles
Hi Folks,
For anyone interested we did an experiment with the reflectix material. Below were the results. It's a little lengthy but pretty interesting.

RELECTIX INSTALLATION EXPERIMENT

Okay I posted about the ability of our 13.5k AC unit of cooling our 28ft TT off during high temp days. On Thursday it was 99-100 from 11am until about 3pm. I could not get the interior temp below approx. 78 degrees measured with a digital thermometer.  During that time 1 shade of the travel was shaded and the other exposed ti direct sunlight.  I measured interior surface temps at windows. ceiling, windows, vents and skylight with an infrared thermometer. We then put up Reflectix, and vent cushions and re-measured on Friday.
My findings here. Fridays conditions were exactly the same as Thursdays 99-100 from 11am to 3pm.
We installed Reflectix on all of the interior windows. Most where held in place by the pulldown blinds but needed to use so Velcro dots on the larger ones.  Temp at window before install was 91 degrees temp after install was 80-82 degrees.  9-11 degrees cooler.
We installed the vent cushions in the vent in the bathroom and in the kitchen area.  Easily a 10 degree temp reduction at both.
We installed the reflectix at the skylight in the bathroom.  Temp before was 97 and after it went UP to about 106 much to my surprise. I thought about it for a while and looking at the skylight I have 2 plastic covers 1 higher than the over.  It is possible that the 2 pieces were acting liking a magnify glass and heated up the Reflectix even more. Conclusion here is to find a cushion to fit the skylight. I don?t think that the Reflectix helped here at all. I may try it again to validate my finding.
We didn?t do any of the interior cabinets this trip so data will come next trip.
The interior walls were once again 84 degrees on the shady side and 88 degrees on the sunny side.
Ran AC on high fan and set to 76 degrees. After a while the compressor shut down and my digital thermometer read 75. So I reset temp to 72 degrees and after a while comp shut down again. Temp reading was 71. Air coming out of the AC ducts was about 46-47 according to the digital and the infrared therms.  We probably could have made it cooler if we wanted to but we where very comfy at the 71 degrees.
Conclusion the reflectix helped tremendously with the heat gain to the interior of the trailer. I will be placing in into the cabinets and storage areas on the next trip as I am very interested to see if it helps in these areas also. Thank you for reading thru this lengthy post. If you have questions feel free to ask me.
 

lungesport

Member
Joined
Nov 12, 2017
Posts
15
Location
SF Bay Area
Good knowledge there... I like the fact that Reflectix protects againts the damaging UV rays that degenerate all things RV.
 

blw2

Well-known member
Joined
Aug 9, 2012
Posts
3,325
Location
Saint Johns, FL
I've not measure and quantified, but I've been using it in my windows for storage, and the pillows in the vents.  Noticeable results for sure.

At first I used reflectix in the roof vents and my shower skylight...also a similar result as you.  I had problems getting and keeping a good fit.  I have assumed the shower didn't work as well because the heat reflected by the reflectix (and also blocked by it's small R-value) is just trapped inside ...some inside the shower and perhaps some between the two domes.  I had my roof sprayed by rvroof.com, but that's another story.  When they sprayed it I had them to spray over the skylight dome.  I'm glad I did!  Incidentally, it seems like the roof coating added R-Value too.

and your comment about insulating the back of the cabinets.  Great idea....Can't believe I never thought of that!  I'm especially thinking the cabinet over the fridge.  It really gets hot in there.  I might even consider putting some real foam insulation there if I ever come across a small piece
 

John From Detroit

Well-known member
Joined
Apr 12, 2005
Posts
24,794
Location
Davison Michigan
First time I put ReflectX in just the main windshield on this Ride this year.. IT was getting hotter and hotter.. As I installed the Reflectx (held in place by curtains) it went down 2 degrees by the time I'd finished and continuted dropping but I did not record how much.. JUST THAT FAST. .It works folks. There is a downside but since I lift the wipers off the window... That is minimized.

Danger in that too. but minimal.
 

BruceinFL

Well-known member
Joined
Mar 12, 2005
Posts
3,205
Would it be better to put the Reflectix on the outside rather than inside of the windows? I notice that when I put the sun shade on the inside of my truck windshield it gets very hot between the shade and windshield and in that area the headliner glue has deteriorated and the headliner is coming off. 
 

butchiiii

Well-known member
Joined
Sep 8, 2014
Posts
347
Location
Los Angeles
BruceinFL said:
Would it be better to put the Reflectix on the outside rather than inside of the windows? I notice that when I put the sun shade on the inside of my truck windshield it gets very hot between the shade and windshield and in that area the headliner glue has deteriorated and the headliner is coming off.

Possibly. I think that it would work outside as well as inside.
 

Dragginourbedaround

Well-known member
Joined
Jul 15, 2013
Posts
1,453
Location
Southwest FL
We also use reflectix on the inside of the front windshield and inside the cabinets.I have thought about putting it on the outside. One thing I miss is being able to see out that huge window. At least when it?s on the inside I can take it down, but outside would be more trouble. Looking forward to reading about more of your test results.
 

Back2PA

Well-known member
Joined
Jul 26, 2015
Posts
5,766
BruceinFL said:
Would it be better to put the Reflectix on the outside rather than inside of the windows? I notice that when I put the sun shade on the inside of my truck windshield it gets very hot between the shade and windshield and in that area the headliner glue has deteriorated and the headliner is coming off.

It absolutely would be better, if you can figure out a way to attach it securely. Unfortunately it isn't going to look that great.

The very best thing you can do to stop heat/sun from entering is stop it before it touches the rig. They are a pain, but when I bought my coach I had snap-on 90% sun screens made for every window on the coach. Those alone make a dramatic difference on heat getting inside. Before I installed them, and with the drapes open, as one would expect the dash would be very hot to the touch. With the shade screen it is just somewhat warm. I then put the reflectix on the inside (since I've already killed 90% of the sunlight from the outside), and most of the heat has been stopped. As I said all windows have external shades - I use refelctix inside on all windows which get direct sun.

As others have said in related topics, I was also getting a significant amount of heat through the shower skylight. For this I used relectix outside. Since there was no reliable method I could think of to keep it attached during the occasion wind storms, I cut a piece 12" larger on all borders and simply laid some bricks down to hold it - obviously not an elegant solution, and a pain to make multiple trips up the ladder to accomplish. However since I've had periods of a month between trips it has been worth it - by having the relectix outside so no sun touches the skylight, 100% of the heat gain has been stopped. (I have a huge note taped to the inside of the windshield to remind me to remove the skylight cover before driving  ::) )

Yesterday was 111F, measured pavement temp at 167F and the side of the rig in the shade under the awning was 130F. Gonna be 114F today  :-\
 

kdbgoat

Well-known member
Joined
Apr 16, 2014
Posts
6,313
Reading this topic on reflectix brings up a couple of questions for me. From what I have read about reflectix, is that the shiny side goes to the warm side, and there should be an inch or so of air space to the next object, ie wall. How does one install it in a cabinet to maintain that space? Once installed properly, to what temperature does that air space and the corresponding outside wall get to? Is that heat high enough to cause loss of adhesion of the panel, thereby causing delamination?
 

Back2PA

Well-known member
Joined
Jul 26, 2015
Posts
5,766
kdbgoat said:
Reading this topic on reflectix brings up a couple of questions for me. From what I have read about reflectix, is that the shiny side goes to the warm side, and there should be an inch or so of air space to the next object, ie wall. How does one install it in a cabinet to maintain that space? Once installed properly, to what temperature does that air space and the corresponding outside wall get to? Is that heat high enough to cause loss of adhesion of the panel, thereby causing delamination?

A valid question. I do know that the warranty on some residential glass is voided it you use an interior sun reflecting film, because the sun first passes through the glass, hits the film, then gets reflected and passes through the glass a second time. This cause the glass to get significantly hotter than it would without the film. Using foil type products inside any window does the same thing.

In cabinets I would think some sort of semi-rigid insulation would accomplish most/all of the desired effect without concern for reflected heat (but this is just a guess).
 

Gary RV_Wizard

Site Team
Joined
Feb 2, 2005
Posts
73,525
Location
At our Silver Springs FL home
This needs some further explanation.

Reflectix itself is just what the name implies - a reflector.  It has no inherent insulation effect (its R-value is 1).  If you create an air gap between the Reflectix and the surface, you gain the R-value of the air gap, which is probably in the R3-R6 range, depending on depth, tight sealing, etc.  You would get the same R benefit using a piece of 1/8" plywood to form the air gap.  Sooo, Reflectix does decently where radiation is the problem, whether direct sunlight or radiant heat from a hot surface. However, it does nothing for conducted heat. A hot surface will still be hot if you glue Reflectix to it - the heat conducts right through it.

For radiation reflection, a piece of aluminum foil works as well as Reflectix. The extra rigidity of the Reflectix makes it easier to use in some situations, but aluminum foil may be easier for others.  In some cases, gluing aluminum foil to thin plywood or card board makes for an easy-to-install reflective barrier.
 

butchiiii

Well-known member
Joined
Sep 8, 2014
Posts
347
Location
Los Angeles
Gary RV_Wizard said:
This needs some further explanation.

Reflectix itself is just what the name implies - a reflector.  It has no inherent insulation effect (its R-value is 1).  If you create an air gap between the Reflectix and the surface, you gain the R-value of the air gap, which is probably in the R3-R6 range, depending on depth, tight sealing, etc.  You would get the same R benefit using a piece of 1/8" plywood to form the air gap.  Sooo, Reflectix does decently where radiation is the problem, whether direct sunlight or radiant heat from a hot surface. However, it does nothing for conducted heat. A hot surface will still be hot if you glue Reflectix to it - the heat conducts right through it.

For radiation reflection, a piece of aluminum foil works as well as Reflectix. The extra rigidity of the Reflectix makes it easier to use in some situations, but aluminum foil may be easier for others.  In some cases, gluing aluminum foil to thin plywood or card board makes for an easy-to-install reflective barrier.

Gary for the windows I did create something of an airgap. From 1/2 to 1" by mounting the Reflectix on the window frame and not the glass. Fro the inside the cabinet experiment I am not too certain that it will help for the reasons that you stated but will conduct the test anyway to prove or disprove all of the theories/stories that are out there. If it does not help in the cabinets I will then try some rigid foam insulation that is easy to cut and install. I'm going the reflectix route 1st because I've got lots left over from the windows  :)
 

butchiiii

Well-known member
Joined
Sep 8, 2014
Posts
347
Location
Los Angeles
kdbgoat said:
Reading this topic on reflectix brings up a couple of questions for me. From what I have read about reflectix, is that the shiny side goes to the warm side, and there should be an inch or so of air space to the next object, ie wall. How does one install it in a cabinet to maintain that space? Once installed properly, to what temperature does that air space and the corresponding outside wall get to? Is that heat high enough to cause loss of adhesion of the panel, thereby causing delamination?

Mr Goat, I am going to try the Reflectix in the cabinet 1st because I already have it but am leaning towards rigid foam insulation board that can be easily cut and installed which I think will work better in the cabinets.
 

butchiiii

Well-known member
Joined
Sep 8, 2014
Posts
347
Location
Los Angeles
Sun2Retire said:
As others have said in related topics, I was also getting a significant amount of heat through the shower skylight. For this I used relectix outside. Since there was no reliable method I could think of to keep it attached during the occasion wind storms, I cut a piece 12" larger on all borders and simply laid some bricks down to hold it - obviously not an elegant solution, and a pain to make multiple trips up the ladder to accomplish. However since I've had periods of a month between trips it has been worth it - by having the relectix outside so no sun touches the skylight, 100% of the heat gain has been stopped. (I have a huge note taped to the inside of the windshield to remind me to remove the skylight cover before driving  ::) )

Yesterday was 111F, measured pavement temp at 167F and the side of the rig in the shade under the awning was 130F. Gonna be 114F today  :-\

Scott, I was trying to come up will an idea to cover the skylight. As we don't stay but a week at most I have a bus tray that would fit over it perfectly and would stay in place unless it got really windy. I'm going to try that on my next outing :))
 

kdbgoat

Well-known member
Joined
Apr 16, 2014
Posts
6,313
butchiiii said:
Mr Goat, I am going to try the Reflectix in the cabinet 1st because I already have it but am leaning towards rigid foam insulation board that can be easily cut and installed which I think will work better in the cabinets.

Where's that Mr. Goat keep coming from? ;D Plain ol' Goat is good enough. 8)
 

Isaac-1

Well-known member
Joined
Dec 3, 2016
Posts
4,576
Location
SW Louisiana
If you want cheap and reflective try mylar emergency blankets, they typically sell for under a dollar each when buying a 10 pack online, though when trying to save a penny watch out for the size, not all are the same.
 

Dennis1336

New member
Joined
Jul 3, 2019
Posts
1
Question, After placing reflexive insulation in my shower skylight I found the insulation became very hot. Is there a chance this will damage the skylight? It was only 75 to 80 degrees outside.
 

TheBar

Well-known member
Joined
Jun 25, 2018
Posts
1,010
Location
MS
Would it be better to paint the roof vent covers and skylight with chrome or aluminum paint?  We have to keep the shower door closed or the big dome shaped skylight acts like a magnifying glass on the interior.
 

John From Detroit

Well-known member
Joined
Apr 12, 2005
Posts
24,794
Location
Davison Michigan
I put up reflected in the front window for the first time this afternoon  Very comfortable inside (But there are other factors)

Not Refletex but just good old Reynolds Wrap.. Like the crazies I put Tin Foil in my half bath window (Turns out it was a perfect fit) about a 5 degree difference almost instantly ..  Yup those solar rays were getting to me :)
 

Forum statistics

Threads
118,516
Posts
1,187,584
Members
123,095
Latest member
goodhumormarc
Top Bottom