styrofoam blown-in insulation

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  #1  
Old 11-23-05, 11:52 AM
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styrofoam blown-in insulation

One never hears about shredded styrofoam being used as insulation. Instead, its only cellulose or fiberglass. now rigid foam claims R-5 per inch, so should shredded foam have some insulating properties?

J
 
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  #2  
Old 11-23-05, 12:24 PM
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styrofoam blown-in insulation

Rigid foam or foam panels have insulation values that range widely depending on the density and composition. The range is from R3 to about R7 depending on the type of foam. Lower density does not mean better insulation.

The lower quality, low insulation stuff (expanded polystyrene) is generally used for meat trays, coffee cups and art projects. It is usually white. It is available shredded because it falls apart or separates easily. It is used as a loose bulk insulation in some walls. One of the biggest problems is the extreme light weight and static electricity that causes it to stick where you not want it to. It is difficult to place with any reliability. It is geneally a waste product with lower insulating values.

The better types (extruded polystyrene - blue, pink & yellow and isocyanurate) are more dense and insulate much better. The availability of these is in shredded form poor and they also have a static problem.

The other loose, bulk insulating materials, cellulose, chopped fiberglass and wool are much better insulating materials in the end than the scrap polystyrene. Foamed-in-place may suffer from shrinkage and installtion problems because of site conditions and crew training.

Dick
 
  #3  
Old 11-24-05, 09:57 AM
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Thanks for the details, Dick. Reason I'm interested is that I've got some of those blue polystyrene rigid foam sheets and thought that shredding them and blowing the shredded foam into tight spaces might be an insulating solution.

I mean, rigid polystyrene claims an R-5 value per inch in depth. But I wonder if I get the same or similar if I shred and blow it. Since I hardly ever hear about blown foam, I was under the impression that its insulation value is not worth the effort.

J
 
  #4  
Old 11-24-05, 07:23 PM
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styrofoam blown-in insulation

I have never seen any reliable figures for the insulating value of shredded polystyrene. The size of the shredded product would have an efffect on the insulating value.

I suspect that the reason you don't see the good polystyrene shredded is that the manufacturers can get a beter price for the insulation in the rigid form without going through all of the shredding, packaging testing and matketing just to sell to low-ball market.

Then you are dealing with bulk products (many of which are rejects or waste), the only thing that really counts to buyers is price. The "junk" insulation cannot compete in the rigid market and the good insulation does not have to be shredded to be sold at a low price. Good rigid polystyrene has more value in its normal form.

Dick
 
  #5  
Old 11-27-05, 09:01 AM
Konrad Fischer
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Some additional remarks may be helpful:

What we found out by testing (Lichtenfelser Experiment) in Germany and by comparing additional insulated appartement houses with the same houses in direct neighbourhood without any improvement ref. insulation:

There is no insulating effect compared with solid materials like wood and brick.

Googling for Lichtenfelser Experiment you can find a pic with a figure of our test, where we had only 10 min IR radiation from a redlight bulb on different insulation materials each 4 cm (From above in opposite ranking: Fiberglass, Styrofoam, Foamglass, Brick, Wood fiber board, gypsum card board, solid pinewood). The temperatures are measured on the back of the boards, fiberglass had 40 degrees increasing, solid wood none!

Besides the lightweight insulation has no capillar activity, what means this materials will never dry out the condensate what must go in, in spite of all vaporproofs, which will be moistured and moldy after some years as our experience shows. I do measure this with my equipement so often in my building consultations all around Germany.

So I recommend not to crumble or blow some lightweight insulation in your construction, instead take solid wood boards if you must have a additional thermal insulation f.e. in attics. About 6-8 cm would be good. If you have a masonry or solid wood wall, no additional insulation is necessary at all. In summer cool, in winter warm, thats the effect of solid material enveloping the rooms.

Some explanations ref. radiation and heat conductivity:

The problem is the way to measure the R-value. Not many in building branche
knows how this is done. Warm air is ventilated to the proof material, cools off and is warmed again outside the 'proof box'. The amount of energy to rewarm is the base for the R-value. It tells only something about cooling of warm molecules on colder surface molecules of the test material.

But: Does the cooling of your hand on a steel plate and a carpet in your room with both room temperature say anything about the wandering of IR radiation through the materials?

Will sunlight - also an electromagnetical radiation - shine through an 1 cm board of styrofoam? And wood? So you can see what works best against IR
radiation. And it is IR radiation, what is reasonable for about 99% of temperature losses through material, believe it or not.

And what is going on in a heated room? In a 20 sqm room there are about 60 kgs heated air giving energy in the facade wall, but about 5-10 tons of IR-radiating wall surfaces, the radiation is nearly on the level of air temperature, you can measure it at the wall by IR-thermometer. So about 99% of the heat transport through materials is radiation (by photones/phonones).

So lightweighters in the building construction are a really pest and only a fake and hoax of 'our' industries and their obscene slaves in science and administration! They damage buildings, invests and - most important - make persons ill with asthma, allergy etc. Even in cellulose insulation is found mold after some time, in spite of all the poison (borates) they give in against it.

Thats the thing: No lightweighters as thermal insulation in and on the walls, in attics, under floors, in the foundations and so on. There is only one good purpose for those - as carpets, to keep the feet warm. Because the molecular contacts are fewer than the marbles on the floor can offer to the warm feet. And so there will be fewer thermal losses by direct molecular contacts. Inspite they have the same room temperature. You can prove that also by measuring with an simple IR thermometer.

Surprising? But true. And well known in earlier centuries from all building experts.

Look on the good old buildings. Modern craftsmanship and engineering is the biggest danger for them, isn't it?
 
  #6  
Old 12-24-05, 12:41 PM
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different philosophies

Konrad,

I've seen construction all over Europe, from Germany to Russia and back. Everything is built solid. Solid stone walls, solid timber roofs and floors, solid insulation, as you describe.

In America, everything is light. All houses are pine wood, thin ply sheeting, and glass or foam insulation. Heavy materials are not practical here.

To combine light construction with heavy insulators or vice versa, is a philosophical problem as much as a practical one. Here, most houses cannot suppport the weight of slate or terracotta roofs.

J
 
  #7  
Old 01-05-06, 03:49 AM
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It's very interesting to know about these construction differences between the US and Europe. Although it would seem like the solid construction would be much more expensive, is this really true...are there other factors that balance out the cost?

jb
 
  #8  
Old 01-05-06, 10:56 AM
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styrofoam blown-in insulation

Solid construction is more expensive than the lightweight construction in the U.S. Heavier construction (concrete, masonry, adobe, etc.) is much more common almost everwhere in the world. The reasons are local availability, sound and fire properties, traditions and preferences.

The U.S. and Canada got started in wood construction because they had to cut down trees to find a place to live and grow food, so they built out of it. There were no options since there were no other established building materials available as there were in Europe.

People moving to the U.S. often have a hard time satisfactory finding housing they are comfortable with. They did not grow up in noisy structures with springy floors. They also are not accustomed to the temperature variations we get in U.S. homes. In some cases, fire is a very big concern. Where they came from lightweight wood construction often had a stigma and was a sign of lower class housing.

Their concept of energy use in a residence is not based on a laboratory steady state test (R-value), but on a dynamic method that recognizes the benefits of mass, thermal storage and capacity. Their concept is not easy to be marketed by a pink animal, but is based on long term performance.

Their concept of a home is something that will last forever, not just a hundred years.

I have several friends that looked for over a year in a major metro area to find solid residential construction outside of high rise condos.

My Russian friends could not understand our construction. They could understand a fireplace, but no using it in a wood home. When I showed them a model home ($500,000 log home), they asked why we build out of firewood. you don't see fire stations as commonly in many European countries.

It is all a material of traditions and preferences.

Dick
 
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