Insulation

TurnThePage wrote:
The Imagine line uses that "radiant foil" insulation to get those big numbers in the floor and ceiling. I'm not knowledgeable enough to know exactly how the system works, but I'm comfortably sure you're not actually getting R40 insulation value.

Yes, the folks who make the reflective barrier/plastic insulation tout those high R- numbers and the way they back up their claims is that it is calulated using the foil barrier film and an airspace that is hermetically sealed. The bulk of the insulation value is done by the sealed airspace and not the plastic film. The RV mfgs just copy and paste the barrier R- number information into their brochures. It is deceptive and borderline, fraudulent.

When I restored my old Starcraft, the major impetus was to get as much insulation value as possible in the spaces available. To that end, I used extruded polystyrene in the frame cavities, A polystyrene film as vapor barrier, and an additional polystyrene panel over the frame and underneath the paneling that serves as a thermal break. Wheel weels were treated the same. I also installed Low-E windows. I accomplished what I set out to accomplish and the interior noise level is super quiet. With the door shut, I can barely hear passing vehicle traffic.
A 1200W heater at 25f ambient will raise the interior temp from 25f to 75f within 30 minutes.

I wish to thank everyone for taking time to respond to inquiry,

wsnider4853

myredracer wrote:

Ralph Cramden wrote:

TurnThePage wrote:
The Imagine line uses that "radiant foil" insulation to get those big numbers in the floor and ceiling. I'm not knowledgeable enough to know exactly how the system works, but I'm comfortably sure you're not actually getting R40 insulation value.

Correct answer. The only places an R30 or
R40 rating is obtainable is in those glossy brochures, manufacturers websites, or on Fantasy Island or the label on the reflective barrier they use. Even if the radiant foil actually worked as advertised, or they increased the roof height and floor thickness to get 11" of uncompressed batt insul in, if you were to disassemble your trailer piece by piece you would find the installation looks like it was done by a pre school class.

^^^100% agree. R-40, if it was batt type, would mean it's about a foot thick which isn't possible. Rigid foam would also be almost as thick so it's not that either. So it sounds like a false claim on the insulation value of a radiant barrier.

Radiant barriers like Reflectix for ex., just do not perform as promoted. They are often marketed as having very high insulating values but there is no specific standard for these radiant type insulation products. Therefore, be wary of product & RV manufacturer's thermal performance claims. Research shows that these radiant barriers can have R-values of R-0 to R-3.5 per thickness. IOW, it's snake oil... I have not come across any scientific testing that demonstrates that it actually works or is cost effective.

Any insulation is only as good as it's installation (and we know what reputations TTs have for overall quality). There used to be an online factory tour vid of one of the major TT manufacturer's plant (now seems to be removed). It showed them laying fiberglass batt insulation right over the top of the roof trusses then putting the OSB on top of that. Compressing batt insulation substantially reduces its R-value. As well, there are typically voids in the ceiling insulation everywhere. Front and rear caps and floors are also poorly insulated with batts.

Most (all?) walls have open cell rigid foam insulation (expanded polystyrene) with an R-value of R-4 per inch. This is a really bad choice in RVs because there is no vapor barrier on the inside walls like in buildings. Warm moisture-laden air migrates through the foam to the exterior skin and condenses, leading to rot, mold and delamination. That is why it is very important to vent your RV in cold weather or to use a dehumidifier. Closed cell rigid foam (the pink or blue expanded poylstyrene stuff) is what they should be using and moisture cannot migrate through it, but it'd add a couple of $$ to the final cost of an RV. A better one still would be polyisocyanurate (aka ISO board) with an R-value of R-6.5. This is what they use in freezer walls and garage doors but is a lot more expensive.

The absolute best insulation in ceilings and floors would be spray-on foam but is too expensive.

Radiant barriers are useful in hot climates for reducing heat gain in attic spaces, and that's about it. They do nothing to reduce thermal conduction losses, which is what fiberglass and rigid foam do.

Compared to a lot of trailers, those are really good numbers. You will be fine. Look for double pane windows. Use an insulation pillow in the vents.

I look for good windows so I can park the rig in the sun and get a lot of solar gain during the day.

donn0128 wrote:
It is what it is. Its just impossible to add more insulation value to a 2 inch thick wall. Not to mention thr R zero windows. If your planning to winter north of the Mason Dixon line plan on being cold.

I camp down to -30C/really cold F with the rig in my sig. R7 walls and R10 roof/floor.

The only thing is it costs a few shiny pennies worth of propane and electricity to keep warm. A new rig with decent ceiling and floor R values and skirting would be a lot easier and most certainly less expensive.

Ralph Cramden wrote:

TurnThePage wrote:
The Imagine line uses that "radiant foil" insulation to get those big numbers in the floor and ceiling. I'm not knowledgeable enough to know exactly how the system works, but I'm comfortably sure you're not actually getting R40 insulation value.

Correct answer. The only places an R30 or
R40 rating is obtainable is in those glossy brochures, manufacturers websites, or on Fantasy Island or the label on the reflective barrier they use. Even if the radiant foil actually worked as advertised, or they increased the roof height and floor thickness to get 11" of uncompressed batt insul in, if you were to disassemble your trailer piece by piece you would find the installation looks like it was done by a pre school class.

^^^100% agree. R-40, if it was batt type, would mean it's about a foot thick which isn't possible. Rigid foam would also be almost as thick so it's not that either. So it sounds like a false claim on the insulation value of a radiant barrier.

Radiant barriers like Reflectix for ex., just do not perform as promoted. They are often marketed as having very high insulating values but there is no specific standard for these radiant type insulation products. Therefore, be wary of product & RV manufacturer's thermal performance claims. Research shows that these radiant barriers can have R-values of R-0 to R-3.5 per thickness. IOW, it's snake oil... I have not come across any scientific testing that demonstrates that it actually works or is cost effective.

Any insulation is only as good as it's installation (and we know what reputations TTs have for overall quality). There used to be an online factory tour vid of one of the major TT manufacturer's plant (now seems to be removed). It showed them laying fiberglass batt insulation right over the top of the roof trusses then putting the OSB on top of that. Compressing batt insulation substantially reduces its R-value. As well, there are typically voids in the ceiling insulation everywhere. Front and rear caps and floors are also poorly insulated with batts.

Most (all?) walls have open cell rigid foam insulation (expanded polystyrene) with an R-value of R-4 per inch. This is a really bad choice in RVs because there is no vapor barrier on the inside walls like in buildings. Warm moisture-laden air migrates through the foam to the exterior skin and condenses, leading to rot, mold and delamination. That is why it is very important to vent your RV in cold weather or to use a dehumidifier. Closed cell rigid foam (the pink or blue expanded poylstyrene stuff) is what they should be using and moisture cannot migrate through it, but it'd add a couple of $$ to the final cost of an RV. A better one still would be polyisocyanurate (aka ISO board) with an R-value of R-6.5. This is what they use in freezer walls and garage doors but is a lot more expensive.

The absolute best insulation in ceilings and floors would be spray-on foam but is too expensive.

Ralph Cramden wrote:

TurnThePage wrote:
The Imagine line uses that "radiant foil" insulation to get those big numbers in the floor and ceiling. I'm not knowledgeable enough to know exactly how the system works, but I'm comfortably sure you're not actually getting R40 insulation value.

Correct answer. The only places an R30 or
R40 rating is obtainable is in those glossy brochures, manufacturers websites, or on Fantasy Island or the label on the reflective barrier they use. Even if the radiant foil actually worked as advertised, or they increased the roof height and floor thickness to get 11" of uncompressed batt insul in, if you were to disassemble your trailer piece by piece you would find the installation looks like it was done by a pre school class.

The thing people fail to realize is that high number for "Radiant foil" has is only for warm temps - not cold. This is printed directly on the product.

There are trailers made with 3” walls . Open Range x3 & Mobile suites are ones I know of

donn0128 wrote:
It is what it is. Its just impossible to add more insulation value to a 2 inch thick wall. Not to mention thr R zero windows. If your planning to winter north of the Mason Dixon line plan on being cold.

best answer of day award here. and goes for many questions concerning build quality across the board.


rv's of any type are simply not brick and mortar homes. although some may cost more than brick and mortar.

the full timers i have met here in the southeast follow good weather. deep south in winter, then migrate back up north in hotter months.


we have camped in our entry level 33 ft wildwood tt down to about 25 degrees this past winter augmenting propane furnace with a small 60 dollar oscillating electric heater and was comfortable.

camped in 95 degree weather last summer with a single 13.5 k btu ac and stayed comfortable inside.

TurnThePage wrote:
The Imagine line uses that "radiant foil" insulation to get those big numbers in the floor and ceiling. I'm not knowledgeable enough to know exactly how the system works, but I'm comfortably sure you're not actually getting R40 insulation value.

Correct answer. The only places an R30 or
R40 rating is obtainable is in those glossy brochures, manufacturers websites, or on Fantasy Island or the label on the reflective barrier they use. Even if the radiant foil actually worked as advertised, or they increased the roof height and floor thickness to get 11" of uncompressed batt insul in, if you were to disassemble your trailer piece by piece you would find the installation looks like it was done by a pre school class.