"R" for insulation????

Page 2 of 2  


Wrong.
Nick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Alright nick, post Proof foil increases Polyisocyanurate by R3, You Can`t dipshit.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Sorry. I have other things to do than correct your many mistakes.
Nick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Right Nick, you post numbers but cant prove anything, because foil does nothing of real merit to R value, it is a Radiant barrier, no R value of significance. If as you say it increases each side by R3 then R 7.2 - 1" of polyiso would come out near R 13, kind of dumb, yes, maybe you have numbers to prove your dream.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Unlike your arrogance, your ignorance may be curable :-)
You might buy an old copy of the ASHRAE Handbook of Fundamentals and look at the table on R-values of plane airspaces, or look into "System R-values."
Nick
Labeling and Advertising of Home Insulation (R-Value Rule) CFR 16CFR460
(From the U.S. Government Printing Office via GPO Access)
Source: 44 FR 50242, Aug. 27, 1979, unless otherwise noted.
Sec. 460.1 What this regulation does.
This regulation deals with home insulation labels, fact sheets, ads, and other promotional materials in or affecting commerce, as "commerce" is defined in the Federal Trade Commission Act. If you are covered by this regulation, breaking any of its rules is an unfair and deceptive act or practice or an unfair method of competition under section 5 of that Act. You can be fined heavily (up to $10,000 plus an adjustment for inflation, under Sec. 1.98 of this chapter) each time you break a rule...
460.5 R-value tests.
R-value measures resistance to heat flow. R-values given in labels, fact sheets, ads, or other promotional materials must be based on tests done under the methods listed below. They were designed by the American Society of Testing and Materials (ASTM). The test methods are: All types of insulation except aluminum foil must be tested with ASTM C 177-85 (Reapproved 1993), "Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus;" ASTM C 236-89 (Reapproved 1993)...
The tests must be done at a mean temperature of 75 deg.Fahrenheit. The tests must be done on the insulation material alone (excluding any airspace). R-values ("thermal resistance") based upon heat flux measurements according to ASTM C 177-85 (Reapproved 1993) or ASTM C 518-91 must be reported only in accordance with the requirements and restrictions of ASTM C 1045-90, "Standard Practice for Calculating Thermal Transmission Properties from Steady-State Heat Flux Measurements."
Aluminum foil systems with more than one sheet must be tested with ASTM C 236-89 (Reapproved 1993) or ASTM C 976-90, which are incorporated by reference in paragraph (a) of this section. The tests must be done at a mean temperature of 75 deg.Fahrenheit, with a temperature differential of 30 deg.Fahrenheit.
Single sheet systems of aluminum foil must be tested with ASTM E408 or another test method that provides comparable results. This tests the emissivity of the foil--its power to radiate heat. To get the R-value for a specific emissivity level, air space, and direction of heat flow, use the tables in the most recent edition of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers' (ASHRAE) Handbook. You must use the R-value shown for 50 deg.Fahrenheit, with a temperature differential of 30 deg.Fahrenheit.
For insulation materials with foil facings, you must test the R-value of the material alone (excluding any air spaces) under the methods listed in paragraph (a) of this section. You can also determine the R-value of the material in conjunction with an air space. You can use one of two methods to do this:
You can test the system, with its air space, under ASTM C 236-89 (Reapproved 1993) or ASTM C 976-90, which are incorporated by reference in paragraph (a) of this section. If you do this, you must follow the rules in paragraph (a) of this section on temperature, aging and settled density.
You can add up the tested R-value of the material and the R-value of the air space. To get the R-value for the air space, you must follow the rules in paragraph (c) of this section.
For aluminum foil: the number of foil sheets; the number and thickness of the air spaces; and the R-value provided by that system when the direction of heat flow is up, down, and horizontal.
For insulation materials with foil facings, you must follow the rule that applies to the material itself. For example, if you manufacture boardstock with a foil facing, follow paragraph (b)(4) of this section. You can also show the R-value of the insulation when it is installed in conjunction with an air space. This is its "system R-value." If you do this, you must clearly and conspicuously state the conditions under which the system R-value can be attained.
Also see:
http://www.atlasroofing.com/downloads/brochures/residential/atlas_sheathing_rackbro.pdf
and
http://www.reflectixinc.com/PDF/RIMA_Handbook.pdf
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Wake up senile nick, R value is R value, a standardised measurement used to measure insulations effectiveness, resistance to heat flow. Polyiso foilfaced, Both Sides is R 7.2" new, 6.8R" stabilised. Your mythical dreamworld of R 6 added with 2 sheets of foil does not exist anywhere in reality or at any store on this planet, or it would be sold as R 12.8* polyiso, and it is not.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
m Ransley wrote:

Nick appears to believe that he is a reincarnation of a mythical all-knowing, all-powerful being. His attitude towards others reinforces this idea with almost everything he posts.
patent holders are idiots.
Facts are false.
Everyone else besides Nick are absolute morons is the message he conveys
Aluminum foil is tested for 'emissivity' not R value. That is the test is to see how good a RADIATOR it is not how good and INSULATOR it is. If it is used for cookware and electric power distribution, it CAN'T be an insulator of heat or electricity.
Aluminum is therefore a RADIANT barrier, and may also act as a vapor retarder, but it does NOT improve an INSULATION material's ability to restrict the movement of heat, EXCEPT by REFLECTING the heat - but it RADIATES to BOTH sides of the foil. An AIRSPACE MUST be incorporated in order for the foil to be effective and the literature that Nick quotes indicates this as well.
So Foil helps, BUT only when there is a air gap. Foil faced insulation is more effective than non foil faced insulation only when there is an air gap for the foil to radiate heat into. Even then, if there is no circulation of that air, we get a heat buildup between the foil and the outside sheathing that could take most of the night to dissipate.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Some of us can calculate the R-value based on the emissivity :-)

Wrong.
Wrong.

Right :-)
Nick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It can work that way in the real world, but it's illegal to advertise R12.8, according to US federal regs, because the R-value depends on the installation conditions, which is confusing to the general public. Altho we can measure and calculate and advertise the "system R-value," if we have the merest grasp of physics :-)
Nick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That would be closed cell.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
R is the fraction of heat loss compared to an air gap the same thickness. So R-19 insulation will conduct 1/19 as much heat as an air gap the same thickness. If you place two pieces of insulation on top of each other you can add the R value. For example two 6" fiberglass bats (R-19 each) equals R-38.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
2006:

We're talking two different strategies for insulating a crawl space here, I believe. You intended to put fiberglas batts between the floor joists, and he wants you to insulate the walls of the crawlspace.
The difference is how the crawlspace functions. In your system, it stays close to the temperature (and humidity) of the outside air. You open the small vent windows in the summer and block them off in the winter. In his system, the crawlspace is insulated space -- warmer in the winter and colder in the summer. The crawlspace isn't ventilated at all in any season.
So it seems to me you and he are talking apples and oranges. Both methods are routinely used these days. You might want to talk to your local utility and get their recommendation for what works well in your area -- and, if you seal the crawlspace, how to deal with heating equipment in the crawlspace (needs an intake air duct for combustion air).
--
Doug Boulter

To reply by e-mail, remove the obvious word from the e-mail address
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Have you tried Aluminium foil its cheaper and more practical fire resistant and easier to install it is something you could buy from a grocery store R means retardant cece e. wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

And has _zero_ insulation value. Except inosofar as it may seal air leaks. He's trying to insulate it, not improve its fire resistance.

R is insulation factor. Not fire retarding rating.
--
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.