RV.Net Open Roads Forum: Fifth-Wheels: Some 5th wheels actually advertise R-38 ceiling/floor.....

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Help and Support  |  Contact

Search:   Advanced Search

Search only in Fifth-Wheels

Open Roads Forum  >  Fifth-Wheels

 > Some 5th wheels actually advertise R-38 ceiling/floor.....

This Topic Is Closed  |  Print Topic  |  Post New Topic  | 
Page of 4  
Prev  |  Next
Sponsored By:
Pete_k

Stantonville Tn

Senior Member

Joined: 03/18/2004

View Profile


Offline
Posted: 01/24/13 10:28pm Link  |  Print  |  Notify Moderator

Dayle1 wrote:

For radiant barriers to achieve high R values, they require an air space on at least one side. Sometimes the air space must be a dead air space of significant thickness, like the 6 to 10 inches available in typical house rafters (something not available in RVs). And a dead air space means no air flow, rather than a leaky air space.

In RVs, this stuff is used in slide outs where it is in direct contact on both sides. Same thing when used in an RV ceiling. Here is what Reflectix says about these situations.

Question "What if There is No Air Space Present on Either Side of the Product?"
Answer "No Air Space = No Reflective Insulation Benefit
(An R-1.1 is provided from the product itself for the Reflective/Double Bubble material.) "

When used in an underbelly, it is frequently in direct contact with the belly liner and an air space above, but it is not a dead air space if there are holes thru the main frame rails for the slide outs, etc and holes thru the floor for wires and plumbing.


I have used the kind we have to wrap a bait tank with. 2 layers stuck to each other. Worked perfect. Put it down in our 400SF bedroom floor then put hard wood over it. Keeps the floor warm as can bed. I'm sure some types work better then others.
Pete


2005 Chevy Kodiak c5500 Cummins 5.9/Allison Trans
2012 Landmark Key Largo
2008 Lund 1825 Pro Guide Tiller, With a Evinrude 90 HP E-Tec
Live near Pickwick Dam and the Tn river

BillB800si

S.E. MICHIGAN

Senior Member

Joined: 01/09/2006

View Profile



Good Sam RV Club Member

Offline
Posted: 01/25/13 06:43am Link  |  Print  |  Notify Moderator

Want to know the truth about this so called radiant foil insulation??'
Then take a look here: Radiant foil

There's not a single RV manufacturer out there supplying a MINIMUM of 3/4 of an inch dead air space for the radiant foil to be effective. This is an advertising gimmick to sell their product at inflated prices.

The good old "pink stuff" (fiberglass) inch for inch still beats styrofoam for insulating properties.

Happy trails,


Bill B. (Michigan)
2007 Dodge Ram 2500 MegaCab CTD
2014 Keystone Cougar High Country 321RES trailer

Cummins12V98

on the road

Senior Member

Joined: 06/03/2012

View Profile


Offline
Posted: 01/25/13 11:52am Link  |  Print  |  Notify Moderator

BillB800si wrote:

Want to know the truth about this so called radiant foil insulation??'
Then take a look here: Radiant foil

There's not a single RV manufacturer out there supplying a MINIMUM of 3/4 of an inch dead air space for the radiant foil to be effective. This is an advertising gimmick to sell their product at inflated prices.

The good old "pink stuff" (fiberglass) inch for inch still beats styrofoam for insulating properties.

Happy trails,


Dow rigid blue board 2" thick is 10.0 R value. I think that beats the "pink stuff"


2011 Ram Laramie Longhorn 3500 Dually Long Bed, Cummins 350/800 HO, Towin Machine
B&W Companion Hitch, Maghytec Trans and Rear Dif Covers, AMZ/OIL Top To Bottom
2007 1/2 Mobile Suites 36 SB3 27,000# Combined

Slownsy

USA

Senior Member

Joined: 01/16/2011

View Profile



Good Sam RV Club Member

Offline
Posted: 01/25/13 03:42pm Link  |  Print  |  Notify Moderator

BIIIB800al Sorry but you are wrong about fiberglass werses styrofoam inch for inch


Frank
2012 F250 XLT
4x4 Super Cab
8' Tray 6.2lt, 3.7 Diff.

Dayle1

Spicewood, Tx

Senior Member

Joined: 04/12/2001

View Profile





Offline
Posted: 01/26/13 06:52am Link  |  Print  |  Notify Moderator

Pete_k wrote:

Dayle1 wrote:

For radiant barriers to achieve high R values, they require an air space on at least one side. Sometimes the air space must be a dead air space of significant thickness, like the 6 to 10 inches available in typical house rafters (something not available in RVs). And a dead air space means no air flow, rather than a leaky air space.

In RVs, this stuff is used in slide outs where it is in direct contact on both sides. Same thing when used in an RV ceiling. Here is what Reflectix says about these situations.

Question "What if There is No Air Space Present on Either Side of the Product?"
Answer "No Air Space = No Reflective Insulation Benefit
(An R-1.1 is provided from the product itself for the Reflective/Double Bubble material.) "

When used in an underbelly, it is frequently in direct contact with the belly liner and an air space above, but it is not a dead air space if there are holes thru the main frame rails for the slide outs, etc and holes thru the floor for wires and plumbing.


I have used the kind we have to wrap a bait tank with. 2 layers stuck to each other. Worked perfect. Put it down in our 400SF bedroom floor then put hard wood over it. Keeps the floor warm as can bed. I'm sure some types work better then others.
Pete


Pete,
I just quoted what is stated by a major supplier of radiant barrier, believe them or not, your choice. If you put radiant barrier on a floor PLUS solid wood flooring, then you got the insulation benefit of the wood plus R-1.1 for the barrier per Reflectix, so sure it felt better. But was it super insulation like claimed by many RV manufacturers??

* This post was edited 01/26/13 02:13pm by Dayle1 *


Larry Day
Texas Baptist Men-Retiree Builders since '01
'13 Silverado 3500HD LT 2wd CCSB SRW, custom RKI bed
'11 CrossRoads Cruiser CF32MK loaded
Rig Photos


travelnutz

West Michigan - On the Lakeshore

Senior Member

Joined: 04/09/2006

View Profile



Posted: 01/26/13 09:36am Link  |  Print  |  Notify Moderator

Carriage RV Corp was the first to experiment and actually use AstroFoil in an RV. It was in early 1993 and the RV that was used for experimentation was a Carri-Lite 528RKS fifthwheel trailer. Clarence Yoder (CT Yoder) the founder and owner/CEO of Carriage agreed to building the 5th wheel using AstroFoil in this 5th wheel to see how well it works. Some on this forum know how I know this for absolute certain but I'm not going to give the names of all those involved in the project as I do not have their permission to do so.

If the AstroFoil is used/installed properly, it's reflective and insulating properties are fantastic and truely as advertised by it's manufacturer. Some RV manufacurers are using it in combo properly however, many are not and/or do not know how to properly use the product.

What is AstroFoil? Not to be confused with the other knock-offs such as cheaper made and priced Reflectix etc.

AstrolFoil was developed for NASA as the insulation to be used in space travel and to help protect the occupants from the intense heat of re-entry and the severe cold of outer space. It's "patent life" was exhausted in either 1989 or 1991 if I remember correctly and could then be duplicated. However, all the duplications are not the same as the patented AstroFoil and are much cheaper having 75% or less of the same insulating properties. They still are far more effective than spun glass or foam though. AstroFoil is extremely effective, light in weight, takes up little precious volume of space, and it very cost effective. The foil composite is only 5/16" (8mm) thick and WHEN properly used in a spun glass or dead air space combination, it's R-values are far superior to other commonly used insulating products. Being highly reflective on both sides and impervious to moisture flow whether liquid or in air saturation, it's very effective in reversing heat, cold, or moisture in both directions from the foil's core. A/C cooled air stays in the living areaand heat from the sun's ray reflects away. Just the reverse occurs when the living space is heated so it's warmer inside than the outside ambient air temps. The subject of reflective insulation involves a lot of variations and indepth detail to determine it's exact effect and the RV industry is ripe with some manufacturer's tainted claims with no experimation's done or thermal chamber documentation gathered. Buyer, beware as "cheap" usually always gets you just that "cheap!"

The general rule of thumb is that 50% of a reasonably enclosed and/or reasonably sealed structure's heat is lost thru the ceiling or roof. 25% thru the floor and 25% thru the walls. Air leaks in windy conditions and/or single pane glass windows can or will greatly alter the loss percentages.

I do not work for AstroFoil or and RV manufacturers however, I did own an engineering business for many years and we were involved in many various projects but mainly the Big 3 automotive industry working with pickup trucks, vans, and SUV's.


A superb CC LB 4X4, GM HD Diesel, airbags, Rancho's, lots more
Lance Legend TC 11' 4", loaded including 3400 PP generator and my deluxe 2' X 7' rear porch
29 ft Carriage Carri-lite 5'er - a specially built gem
A like new '07 Sunline Solaris 26' TT

BillB800si

S.E. MICHIGAN

Senior Member

Joined: 01/09/2006

View Profile



Good Sam RV Club Member

Offline
Posted: 01/26/13 09:53am Link  |  Print  |  Notify Moderator

Travelnutz, you bring up some good points to consider.
Would I be correct in saying that if a trailer was insulated with foam or fiberglass and the insulating foil was installed over it that the foam and/or fiberglass would produce the dead air space required for the foil to work?

Just wondering??

travelnutz

West Michigan - On the Lakeshore

Senior Member

Joined: 04/09/2006

View Profile



Posted: 01/26/13 12:31pm Link  |  Print  |  Notify Moderator

BillB800si,

Yes for the most part if the foam is closed cell and fits quite tightly. Closed cell foam is really just trapped air bubbles. The goal is to prevent or retard as much air from moving as possible or practical. With foam insulation it's preferable to lay the foil over the top and tape (seal) the edges to prevent air venting. With spun glass insulation the most effective method is to place the foil between 2 layers of the spun glass and also sealed to stop air movement. It's hard and costly to do in the manufacturing process in an RV roof. Both methods hen using the foil works very well.

Where to best place the foil is a double edged sword because it depends if the unit is used in a very hot climate or a very cold climate. A dry climate or a high humidity climate. Hot and very humid is the worst to deal with but then again an RV etc A/C is not efficient at all in a dry climate as there's so little moisture for it to work with. Then again, dry air doesn't hold heat well either but does if humidity (humidifier) is added. Wet insulation has very little insulating properties whether it's moisture came from inside a structure or from the outside of the structure. One size doesn't fit all as the saying goes. The human body can tell the comfort differences between too much humidity and too little humidity almost better than a guage.

The most effective way to use a foil is to have it on either side of a (case or sleeve) foam or spun glass and be totally sealed to control moisture. Tricky as very warm air can hold many times the water as very cold air. A cold surface in a warm structure sweats as the warm air moisture quickly condenses on a cold surface and you as an RV'er know just what it's like!

Dry adequate air movement restricting insulating R-value is where it's at and is far more important than just how thick the insulation is.

In reality, there is no perfect insulation for all the human inhabiting climates on the planet Earth.

Dayle1

Spicewood, Tx

Senior Member

Joined: 04/12/2001

View Profile





Offline
Posted: 01/27/13 06:43am Link  |  Print  |  Notify Moderator

BillB800si wrote:

Travelnutz, you bring up some good points to consider.
Would I be correct in saying that if a trailer was insulated with foam or fiberglass and the insulating foil was installed over it that the foam and/or fiberglass would produce the dead air space required for the foil to work?

Just wondering??


I have some foam board with a foil face sitting in my garage from HD. It has a chart of R values printed on it and states; 1" polystyrene R value of 3.85 + foil face R value of 0.17 + 3/4" dead air space R value of 2.8 for total R value of 6.82. Below the chart it clearly says that a 3/4" dead air space is required. So it would seem that IF foam or fiberglas was the equivalent of a dead air space, then the manufacturer would not need to specify it was still necessary.

Another point to consider. Bulk insulation (foam or fiberglas) limits conductive heat transfer, it works up, down or sideways and it works 24/7. A radiant barrier is only effective against radiated heat. When the sun is shining, it may work great on the roof or wall exposed to the sun, but what about the other walls and floor? If the air temp is 105 F and the A/C is set at 75 F, those shaded areas only have bulk insulation to limit heat gain from the outside air. Or at night when the sun has set and the air temp is still 90+ F.

In the winter, the propane furnace heats the air in the coach and then objects are heated via convection. Now when the furnace turns off, the objects do radiate heat back into the air, but how much and how far is that heat radiated? If it is significant, then a black object will absorb heat radiating from other nearby objects and have a higher surface temp than they do. If you are using a radiant heater rather than the furnace, then a radiant barrier in winter would be more beneficial.

Food for thought.

travelnutz

West Michigan - On the Lakeshore

Senior Member

Joined: 04/09/2006

View Profile



Posted: 01/27/13 09:11am Link  |  Print  |  Notify Moderator

Dayle1 and others as "food for thought",

Spun glass insulation is basically the same as a dead air space and with 1-1/2" on either side of the AstroFoil more than meets the manufacturer's installation requirements. Bear in mind that the spun glass also supports and maintains the dead air space. You are confusing a single sheet thickness of aluminum foil on the foam with the following matrix buildup of the AstroFoil:

1 sheet of plastic film

1 sheet of aluminum foil

1 sealed dry dead air filled bladder 1/4" thick bonded between 2 layers of plastic film. Some refer to it as hightech bubble wrap.

1 sheet of aluminim foil

1 sheet of plastic film

All are bonded together in a continous sandwich that's impervious to moisture transfer, air transfer, radiant heat transfer, as well as restricting thermal heat transfer, while being very thin and extremely light in weight. If there was something better than what the AstroFoil properties/efficiency produce you can bet that NASA and the U.S. Military would be using it instead.

In RV's etc your biggest enemy for human comfort IS radiant/radiated heat and cold and air infiltration whether it comes from the inside of the RV or the outside of the RV. The AstroFoil is very effective in accomplishing both as it's 2 sided with a completely sealded dead air space between. Simply stated: The AstroFoil properly installed makes the work of either a furnace (heat source) or an A/C (cooling source) so much easier because it contains the desired warmed air or cooled air inside while reflecting the un-desired factors away.

Also, the U.S. Military and many beach dwellers use sheet foil covered or containing blankets to maintain body temps in the heat or cold. Why do you think that is? Hmm, and why do people in kitchens cover the stuff their baking in ovens with aluminum foil? So many other examples. The answer is very obvious!

edited to correct a typo

* This post was edited 01/27/13 01:36pm by travelnutz *

This Topic Is Closed  |  Print Topic  |  Post New Topic  | 
Page of 4  
Prev  |  Next

Open Roads Forum  >  Fifth-Wheels

 > Some 5th wheels actually advertise R-38 ceiling/floor.....
Search:   Advanced Search

Search only in Fifth-Wheels


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:

© 2014 RV.Net | Terms & Conditions | PRIVACY POLICY | YOUR PRIVACY RIGHTS