# R Values



## Tangooutback (Apr 16, 2010)

Does anyone know the R value rating on our Outback's walls, roof and floor? 
It seems to me the R rating must be very low. For my 25RSS if outdoor temperature is 90 degrees, the a/c runs non stop and it barely stays at 78 degrees inside. My a/c unit is barely one year old and has seen about 12 days of use last summer.


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## Insomniak (Jul 7, 2006)

Walls R-9, floor & ceiling R-14 from the Keystone web site.


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## TwoElkhounds (Mar 11, 2007)

Single pane windows probably do not help either.

DAN


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## duggy (Mar 17, 2010)

I don't know about the older Outbacks, but I find the R-9 claim a little hard to swallow. Their website says the walls are

*Walls - Construction *

 1 1/2" welded aluminum walls with R9 insulation
 Solid block foam insulation I've measured the walls of our 2011 Outback where there are openings, and the foam is 1" thick. The overall wall thickness including filon, luan mahogany outer skin, foam or aluminum frame, and luan mahogany inner skin, is a thin 1 3/8". That doesn't leave room for a 1 1/2" frame and foam.
As a builder, I know that 1" of high density foam such as styrofoam SM, has an "R" value of 5. The bead board foam like they use in travel trailers has an "R" value of 4.5 per inch.

It may be true that with 1 1/2 inches of foam plus two layers of luan mahogany plus filon on the outside and wallpaper on the inside, that the total "R" value is 9. However, with 1" foam I expect it's more like R 6.5

Our Surveyor TT _did_ have 1 1/2 inch walls, and maybe at one time Outbacks did too, but they don't any more, and they should update the website.


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## KTMRacer (Jun 28, 2010)

duggy said:


> I don't know about the older Outbacks, but I find the R-9 claim a little hard to swallow. Their website says the walls are
> 
> *Walls - Construction *
> 
> ...


regardless of the wall/ceiling etc. the windows are a BIG contributor to heat gain/loss. Single pane windows have a low R value (maybe 3??) and look how much of the exterior wall area is windows!


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## Tangooutback (Apr 16, 2010)

KTMRacer said:


> I don't know about the older Outbacks, but I find the R-9 claim a little hard to swallow. Their website says the walls are
> 
> *Walls - Construction *
> 
> ...


regardless of the wall/ceiling etc. the windows are a BIG contributor to heat gain/loss. Single pane windows have a low R value (maybe 3??) and look how much of the exterior wall area is windows!
[/quote]

I read in a homebuilder magazine few years back about window R values. It said best window was triple pane and with R=2 to 2.5. Single pane was 0.5. The biggest advantage of double or triple pane window, according to this article, was condensation prevention.


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## duggy (Mar 17, 2010)

Tangooutback said:


> I don't know about the older Outbacks, but I find the R-9 claim a little hard to swallow. Their website says the walls are
> 
> *Walls - Construction *
> 
> ...


regardless of the wall/ceiling etc. the windows are a BIG contributor to heat gain/loss. Single pane windows have a low R value (maybe 3??) and look how much of the exterior wall area is windows!
[/quote]

I read in a homebuilder magazine few years back about window R values. It said best window was triple pane and with R=2 to 2.5. Single pane was 0.5. The biggest advantage of double or triple pane window, according to this article, was condensation prevention.
[/quote]

I've always understood that single pane windows were about R1. Double pane sealed units with Low "E" and argon gas get to around R4. While adding sealed thermopane windows would help save heat and reduce condenstaion, they would add quite a bit of weight to the trailer, and they would be prone to seal failure from vibration.

The main source of heat loss is through the roof of any enclosure. They say it's R14, but that is anybodies guess. I've heard some members say when they installed roof speakers, there were large areas missing insulation. For the most part, I guess we'll never know.


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## Tangooutback (Apr 16, 2010)

duggy said:


> I don't know about the older Outbacks, but I find the R-9 claim a little hard to swallow. Their website says the walls are
> 
> *Walls - Construction *
> 
> ...


regardless of the wall/ceiling etc. the windows are a BIG contributor to heat gain/loss. Single pane windows have a low R value (maybe 3??) and look how much of the exterior wall area is windows!
[/quote]

I read in a homebuilder magazine few years back about window R values. It said best window was triple pane and with R=2 to 2.5. Single pane was 0.5. The biggest advantage of double or triple pane window, according to this article, was condensation prevention.
[/quote]

I've always understood that single pane windows were about R1. Double pane sealed units with Low "E" and argon gas get to around R4. While adding sealed thermopane windows would help save heat and reduce condenstaion, they would add quite a bit of weight to the trailer, and they would be prone to seal failure from vibration.

The main source of heat loss is through the roof of any enclosure. They say it's R14, but that is anybodies guess. I've heard some members say when they installed roof speakers, there were large areas missing insulation. For the most part, I guess we'll never know.
[/quote]

We'll never know for sure what true R value is with our trailer, but we do know a 13,500 BTU window unit in our house would be able to keep a room a lot bigger than our trailer and at cooler temperature. On our camping trip last month our trailer a/c ran non-stop all day long. It did not shut down until around 2am and I set temperature at 75, then changed to 77 and again to 79 during sunlight hours. The campsite was on the beach and was fully exposed to sun light.


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## Jewellfamily (Sep 25, 2010)

RV's have almost every aspect of temperature control working against them.

1. The windows are single pane and tend to be extremely large as related to the exterior walls of the unit. They tend to work just like a greenhouse. Keeping the shades closed helps, but its nice to have the windows open for the view and light.

2. The ceiling in the new ones has a higher R value, however there is no dead air space like in your home, so there is a direct heat path instead of an air space with ventilation.

3. The very design of the RV's is a large contributor. The energy required to raise or lower the temperature in a building or RV is dependent on the building materials. In buildings, you tend to use materials with relatively high mass (or density), and a high heat capacity (or thermal mass if you want to think of it that way). You can have the same "R" values in 2 different walls, but the energy required to change the inside space temperature is higher when the building material mass and heat capacities are higher (both a glass wall and a concrete wall have very low "R" values, but it takes a lot of time and energy to heat a room through a concrete wall because of the high thermal mass). The RV manufacturers are continually shaving weight off of the RV's and one of the primary ways to do this is through building material selection. Fiberglass sheeting, aluminum framing, polybead insulation all have low mass and low heat capacities and it takes very little energy to heat up the interior. "R" values affect it as well, but the "R" value is also dependent on the other factors listed here.

Park in the shade, keep the shades drawn on the windows the sun is shining on and if it wont keep up, more cooling btu's...


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## crunchman12002 (Jul 26, 2009)

duggy said:


> I don't know about the older Outbacks, but I find the R-9 claim a little hard to swallow. Their website says the walls are
> 
> *Walls - Construction *
> 
> ...


regardless of the wall/ceiling etc. the windows are a BIG contributor to heat gain/loss. Single pane windows have a low R value (maybe 3??) and look how much of the exterior wall area is windows!
[/quote]

I read in a homebuilder magazine few years back about window R values. It said best window was triple pane and with R=2 to 2.5. Single pane was 0.5. The biggest advantage of double or triple pane window, according to this article, was condensation prevention.
[/quote]

I've always understood that single pane windows were about R1. Double pane sealed units with Low "E" and argon gas get to around R4. While adding sealed thermopane windows would help save heat and reduce condenstaion, they would add quite a bit of weight to the trailer, and they would be prone to seal failure from vibration.

The main source of heat loss is through the roof of any enclosure. They say it's R14, but that is anybodies guess. I've heard some members say when they installed roof speakers, there were large areas missing insulation. For the most part, I guess we'll never know.
[/quote]

Most single pane windows have an R-value below 1.0

I sell windows for Alside. The best window we sell is a triple pane window with LOW-E And Krypton gas which has an R-value of 5.33. Other windows can get an R-values closer to R-10 with Krypton gas and a 1" super spacer. These are replacement windows for a house (3-1/4 thick frames). It would be tough to even retrofit a 1" non-opening insulated glass pack to fit a trailer.
As others have suggested, best thing is heavy blinds, shade for summer, sun for winter.
crunchman


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