| Author |
Message |
vern rainville (68.9.3.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 15, 2004 - 7:24 am: | |
To continue a little here, I meet with Mr. Whipple last week. I checked out his R-38 Insulation and have made some obsevations. This product is only 1/4" thick and has a center of aluminum foil which is sandwiched inbetween foam insulation.The foam is the same type that I use in building houses called "sill seal". Althought I do not believe it has an R factor of R-38 as measured in the same test that you would test fiberglass home type insulation, I do believe it has an R factor of R-38 in differant testing. That test is for radiant tranfer of heat. The best way I can describe this is simply stated that in you bus, sitting in the sun, at 85-90 degrees, with no interior ceiling, being able to look at the interior metal roof skin, your skin would obviously be very warm, if not hot to the touch. With this "radiant" insulation in place, the transfer of "radiant" heat is cut down significantly. So to say that this product works well in reverse, meaning in cold tempurature as "insulation" in the typical sense, I doubt it. Does it hinder the transfer of warm to cold in cold weather conditions???? I think it would, but with insulation, plywood, and roof interior, (not to mention any air space), I doubt it it woud be significant. I plan to chase the sun, not the cold in the years to come. So, a long story short, I will buy this "radiant shield insulation" for my roof only with the expectation that it will perfom well in the summer months, and not as well in the winter months.No substitution for good old insulation. By the way, this product has a peel and stick one side so you can stick it to your roof in one easy application. I will "insulate" my skin only with this radiant insulation and foam fill the roof ribs with the can stuff. No "air space" like some other products I have seen. I have no affiliation with this company. And for those who have asked me to give this company your names, address,and emails, I have done so. I hope this helps any one make up thier minds on whether or not to use this product. I am not an engineer or specialist in this area, just a carpenter making some observations. Vern (in RI) |
Henry R. Bergman, Jr. (63.224.197.10)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 15, 2004 - 4:33 pm: | |
Wow!, R-38 insulaton with only one quarter inch of product. Sounds almost too good to be true.
In the building industry such R ratings usually but not always include the entire roof or ceiling...
...structure. Wonder if this would make a difference in a coach. Right now I am exploring a product...
...call E-Z White which is five sixteenths of an inch thick, with a R rating of around 7. Good luck. |
CoryDane RTSII (66.155.188.169)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 15, 2004 - 11:09 pm: | |
You Said
"with no interior ceiling, being able to look at the interior metal roof skin, your skin would obviously be very warm, if not hot to the touch"
My bus ceiling was in such condition last summer. My bus has a coating of KoolSeal on it and in the summer in 80 to 90 degree days, the bottom side of the roof metal is still cool to touch. Other Users of KoolSeal have had similar results.
I am using a similar but different insulation, 1/4" thick poly interior and metal film on both outside surfaces. Requires the 3/4" dead air space(this is where fiberglas is loosing the R factor". Blah blah, blah.
I feel, along with others, that the KoolSeal Coating is agreat heat reflective surface and should be considered in part of the plan.
"Imagine"
cd |
Nelson (205.188.209.7)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 15, 2004 - 11:17 pm: | |
Is there really any significant difference between kool Seal and a bright white paint? I understand that Kool Seal will caulk and leave white streaks on the side of the coach. I know it will seal leaks but are there any other benifits?
Nelson, Knoxville TN. |
FAST FRED (63.234.22.103)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 16, 2004 - 5:41 am: | |
ITS Cheaper than good paint,but only lasts 1/5 or so as long.
Do it your way,
FAST FRED |
vern rainville (68.9.3.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 16, 2004 - 7:18 am: | |
I agree with the light colored roof as part of the plan. Kool seal is a good, inexpesive product that will seal the roof and keep it cooler than not having it. As far as streaks, I do not know. I will use white paint on my roof as long as there are no leaks, and if there are, probably wil then switch to kool seal. Another interesting area I am looking into along the same lines of insulation is the interior metal ceiling. I know that black paint absorbs heat. To put that on the exterior of my roof would be "suicide" heat wise. I believe that the black paint will also disperse heat quicker than any other color. My thought is to consider putting black paint on the "inside" of my roof pannels (on the metal) in order to disperse the heat. This is just a thought at this time.This was suggested to me recently. Interesting ! Any comments, thought? This is a great place to give thoughts, right, wrong, or indifferent. Vern |
Adame (129.82.229.195)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 16, 2004 - 7:37 pm: | |
They call this "black body radiation". It's the reason why radiators are painted black. Seems like painting the inside of your roof black would radiate heat back down towards the living space.
I painted the inside of my roof with Koolseal for this very reason. It seems to work. I'd do it again. |
CoryDane RTSII (66.155.188.191)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 16, 2004 - 10:44 pm: | |
Ok Guys
I have used KoolSeal on my old, err, very old RV that I installed cool seal on the roof in 1990, yes, the RV is still moving to this day. The cool seal has never leaked since the installation, which is why I put it on in the first place, Leaks.
Ok, as far as chalking, I cant honestly say it has ever been a problem, but every two or three years I clean the roof with a mild soap, very easy and fast.
The Cool Seal dropped the temp inside almost imediately after application and has lasted to this day, going on what, 15 years now. Who said it does not last beleives paint is indestructable I guess.
As for White Paint, I had a White Chevrolet, and the white paint did'nt help for squat as far as heat was concerned.
I beleive that paint does not have the same heat reflective value as the cool seal does, of course I have not placed a peice of white painted metal and cool seal covered metal out for temperature testing but the results on the camper were very dramatic.
As COOL SEAL is not an insulation value, rather a reflector of suns rays, I dont believe it has any value UNDER the roof metal. Thats a different reflectability.
But, I am no chemist and can only go by others results.
"Imagine"
cd |
Mallie (65.38.24.104)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 17, 2004 - 11:41 pm: | |
I read the BCM article and had a really good laugh. Anyone that believes you can get R38 from one inch of any kind of material type insulation has never had the very basics of science and physics.
Hint,, It ain't happening in this world.
All the reflecto crap is worthless when it is includes in a wall. It only works when it has a place to reflect to. Once in a layered wall there is NO radiant transfer, only conduction and convection of the air within the various air spaces.
Mallie Lennon |
CoryDane RTSII (66.155.188.197)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 12:00 am: | |
Mallie
I talked to these people about HighR, they claim, er I think it was 9R or something with the 1/4 poly with metalic sheets on both sides.
They claim the reflection still happens in the wall as long as the dead air space exists.
Do you think a wall with 5/8 foam and this HighR glued on the insdie of the foam, facing the dead air space to the outside, that it would be worthwhile? All these guys say with the 1/4 inch insul, the foam is of no purpose. I think the foam is a backup to the reflecto stuff.
Any opinion?
"Imagine"
cd |
Gary Carter (68.25.65.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 12:53 pm: | |
Keep in mind that in convection insulation it is the dead air that is doing the insulation and not the material. The purpose of the insulation material is to capture air and keep it from moving, thus dead air. |
vern rainville (68.9.3.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 8:57 pm: | |
Mallie, Perhaps you misunderstood my reasoning for this product. It is NOT for the conventional R Value as measured with standard wall insulation.I am planning on using it for deflection, not so much as insulation.With my "very basics of science and physics"I got a piece of this "insulation" and put it on some metal. I used a hair dryer to heat up the opposite side as warm as the hair dryer could reasonably get it. With a second piece of "bare" metal I did the same thing, heat it up too. Simply by putting my hand underneath each of the two pieces, the piece with no insulation was warmer, noticably. I concluded the piece with insulation has done some "deflection" of heat.It it was noticable with my hand. It had done the job I plan to use it for.I am not using it to keep heat in, but rather to keep heat out. I beleive that it will work well in the summer months, not the winter months. I still plan on "standard" insulation, as well as a light colored roof, maybe even a "kool seal" product. Vern Rainville |
Mallie (65.38.24.100)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 19, 2004 - 2:50 pm: | |
Heat is not transferred by radiation in a wall nor in an sealed air space. The reason is there is still air and convection, and conduction. Therefore any reflector used in an sealed, enclosed space is useless Period. The only place a reflector works is when there is a place to reflect the radiant heat to, usually referred to as ventilated space. The exception to this is where there is no air, as in a vacuum.
Mallie |
Mallie (65.38.24.100)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 19, 2004 - 3:35 pm: | |
Hello Vern,, no disrespect for your post, you are just trying to figure it out. I was commenting on the article. What really got me was a man who professed to be an "engineer" telling you this kind of crap.
The Radiant reflective coating do work as designed, to reflect radiant energy before it is turned into heat. But it only works well when in the SUN. Otherwise the radiant heat is miniscule, and in a wall it has no place to reflect.
Many people are confused by this kind of marketing simple because they do not know.
The sun hits your roof, part of the energy is reflected back, part is absorbed and changed to heat. Just go check the surface of a white car, and any other color. You will find about a 40 degree difference. Part of the heat waves are not in the visible light, so color is not the only factor. But what ever the skin temp, the underlining insulation has to deal with it as conducted heat. Most conductive insulation is air based, meaning air is actually used as insulation. Fiberglass, rock wool, etc. So it only stands to reason the total of such a sandwiched wall could not exceed that of still dry air.
Foam is flashed with a gas that has a lower conductivity than air hence higher R rating. But experts say the gas is quickly replaced by air after a few heat and cold extremes.
Remember the laws of gas,, volume/ heat/ pressure.
The bottom line is you are not going to get much higher R value than air unless you have replaced it with a gas of lower conductivity, or just a vacuum. The vacuum is not easy to achieve. There are some gases that do offer great potential, but building a flexible container type bag is tough proposition.
Vern, if you want to conduct test, build you a small box and put a temp probe in it and a small light. With a small calculation you can determine how much heat is being lost through your experimental walls for very real numbers.
Mallie |
vern rainville (68.9.3.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 19, 2004 - 5:26 pm: | |
Mallie, I will try the test you reccomend. I'll make 2 metal boxes, one with and one without the insulation.The one with, I'll use the "insulation" on 5 sides, (top,and 4 sides) leaving the bottom open.I'll use the same thermometer and test it seperately.I'll use a hair dryer for the heat and time it as applied to each box.Any other recomendations as I am eager to learn as this is not my forte. Thanx in advance, Vern (in RI) PS I'll post my results with in the week! |
Mallie (65.38.24.100)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 19, 2004 - 10:48 pm: | |
Vern,, a good comparison would be to compare you composite insulation against the same thickness of high density foam. |
FAST FRED (65.154.176.64)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 20, 2004 - 5:00 am: | |
Mallie's explanation was excellent but did not include the reason for having fiberglass or somthing else in the cavity with the air.
The reason is to slow or try to stop convection , the mixing of the air inside the insulation that helps move heat , just what you dont want.
The cautions on not overstuffing insulation (the more is better theory) is that F/Glass is really a good conductor of heat (as your big glass windows demonstrate) so only enough F/G to slow air convection is needed.
FAST FRED |
vern rainville (68.9.3.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 20, 2004 - 6:47 am: | |
Mallie/ Fast Fred,I am confused. I am thinking this product as a "barrier" from outside hot to inside coach temperature. I am convinced that this is not insulation, but a barrier from heat. My test filling the box with insulation would not demostrate not my purpose.Would you sugest a box with the same set up as I plan in my conversion?That would be metal (roof), paint (interior metal) Radiant insulation (the "product")1 1/2" rigid insulaion (my insulation),aprox 1/12" airspace (that I will have in my ceiling)1/2" plywood (ceiling substrate) and finally vinyl material (my finished ceiling). Would that be a beter comparison of boxes for my test? To add fiberglass to this equasion is not intended purpose. I now I am ignorant of "theory", but this seems to me now, the better way to test it. Or, am I better off putting an airspace of 1 1/2" between the product and the insulation? Vern |
Mallie (65.38.24.99)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 20, 2004 - 10:00 am: | |
Vern,,There are ony 3 ways to move heat, Conduction, Radiation, and Convection. I think you have narrowed your question down to a simple answer. There is no such thing as a heat barrier that stops heat. All insulation conducts heat except a complete vacuum. It simply slows the rate of transfer and that rate is you R value or resistance to heat transfer, which is the reciprocal of the rate of transfer.
There is no heat in the radiant waves. None. When it strike, it either is reflected back, goes through as in glass, or is absorbed and turns to heat.
We are talking about your outer skin. At this point there is NONE of the radiant wave penetrating the skin of your bus,,NONE. What you have is the results of the radiant wave in the form of increased heat. This is where surface and color does a good job of reducing the heat load by reflecting the radiant wave before it turns to heat. This is what a radiant reflector does. But it only works on the surface. The term Radiant Barrier would suggest it might serve well when layered into a wall which is completely false.
You can measure the temp of the skin and evaluate a radiant reflector.
What ever the skin temperature, that is the heat load your insulation will have to deal with. It is all conducted heat load, no radiant.
If you want to test the rate of heat conduction on any give insulation, the box with a light in a controlled heat room is the way to go. The interior will heat to a point of equilibrium, meaning the temperature in the box reaches a point and stands. This means at this point the same amount of heat being generated is being passed through the box. It is just a matter of determining what the wattage, thus the BTU of the light, the difference between the temperature in the box and the stable temp in the room holding the box. Now divide by the sq feet to have the rate the heat is being transferred. With careful attention to detail you can get a pretty close R value. The framing, corners, and floor being the unknowns. But the same comparison test can be run with a know insulation like high density foam and you will get very usable results.
If you want to test the sun's load on the wall as a completed bus, that is simple enough too. Just put the two in the sun and watch the interior thermometer until the temperature stabilizes inside.
Mallie |
Nelson Thomas (64.12.96.79)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 20, 2004 - 10:44 pm: | |
Mallie: You seem to know something about insulation.I am going with the hot spray foam but I haven't got a good answer about how to treat the structural ribs to keep them from conducting heat to the interior on a 4104. the foam will be shaved flush with the ribs. I have limited head room what do you think would work the best?
Nelson Knoxville TN. |
FAST FRED (63.234.20.35)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 21, 2004 - 5:41 am: | |
Insulation OVER the ribs.
FAST FRED |
Mallie (65.38.24.99)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 21, 2004 - 8:15 am: | |
FF is right. Insulate over the rib if you can. Framing member in a house or bus do conduct heat. It is something we often have to live with in a practical world.
Just a half-inch of foam insulation will help a lot. But if it does not work out I would not worry too much.
Mallie |
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