U.S. material use: Fiberglass insulation is a very commonly used insulation material in buildings that is produced in two different forms: blanket and loose-fill. As a method of insulation, fiberglass is used to aide in controlling the temperature and sound in buildings. It is less commonly used to insulate appliances and equipment such as: pipes, roofs, walls, floors, cars, refrigerators, and cooking appliances.
U.S. material consumption: In the U.S. the yearly business revenue for insulation is approximately $8.5 billion [verification needed], but the business is expected to grow 5.3 percent annually through 2012 from increasing demand, due to renewed growth in housing construction. Fiberglass will continue to be the leading material used in insulation and will outpace the demand for foamed plastic, which is the second most commonly used insulation material. The quickest growth will most likely be from reflective insulation and radiant barriers, even though it comes from a small customer base.
Other uses for insulation: Insulation is usually thought of as a way to control temperature and maximize heat loss, but it has other uses as well. It is a great sound absorber and can lower the transmission of sound from other rooms or from outside when it is put into walls and ceilings. Insulation products are also a good way to reduce the transmission of moisture. In the case of fiberglass insulation, the batts and blankets have an outer material that serves a role as a vapor retarder and helps resist the movement of moisture vapor to places where it can condense.
Manufacturing Fiberglass Insulation[edit | edit source]
Fiberglass insulation is made by melting glass and spinning the liquid to create fibers. A binder is added to the fiberglass to hold all of the fibers together. The most common binder added to fiberglass is phenol-formaldehyde, but alternatives are available to help reduce VOC emissions. Studies have not yet declared whether the formaldehyde from the binder affects air quality, so to error on the side of caution one could choose a fiberglass company that uses an alternative binder. All fiberglass insulation that is made in the United States contains at minimum 30% of recycled glass.
Alternative binders: Acrylic (produced by Johns Manville) and rapidly renewable bio-based binder (produced by Knauf)
Regulatory VOC limits[edit | edit source]
There is currently no agreed upon standard for formaldehyde concentrations in residential settings. A few government agencies and organizations have created occupational definitions and levels for formaldehyde, but they differ significantly from each other.
-OSHA Set Permissible Exposure Limit-
The Occupational Safety and Health Administration (OSHA), has set legal permissible exposure limits (PELs) to regulate the exposure of workers in occupational settings to formaldehyde. A PEL is typically given as a time-weighted average (TWA) over an 8-hour period, but it can also be given as a short term exposure limit (STEL). For formaldehyde, OSHA sets the PEL/TWA as 750 ppb in air.
Since the PEL is over an 8 hour period, the PEL/TWA may not be able to detect high exposures during short amounts of time so OSHA also has established PEL/STELs. PEL/STELs regulate over a continuous 15 minute period and determine the concentration levels that workers can be exposed to without suffering health effects. The limit set by OSHA for the PEL/STEL for formaldehyde is 2000 ppb in the air.
-NIOSH Set Permissible Exposure Limit-
The National Institute of Occupational Safety and Health (NIOSH) uses the same formula for time weighted average, but its permissible levels differ. NIOSH defines the TWA as 16 ppb. NIOSH recommends limiting exposures to formaldehyde to levels below detection since the International Agency for Research on Cancer (IARC) reclassified formaldehyde as a carcinogen.
VOCs[edit | edit source]
A major indoor air pollutant of concern is formaldehyde. A large source of this VOC is in pressed wood products, as well as fiberglass insulation. Formaldehyde is an irritant that effects the eyes, nose, throat and lungs. Long-term exposure of this compound may cause cancer. Formaldehyde is just one of the potentially hazardous substances that can be found in indoor air. Other indoor air pollutants include other VOCs such as tetrachloroethylene, trichloroethylene, chloroform, benzene, styrene, and so on. When choosing fiberglass insulation, it is best to go with a formaldehyde free brand. There are companies that offer formaldehyde free insulation, such as Johns Manville at: http://web.archive.org/web/20120512032159/http://www.jm.com/insulation/building_insulation/4465.htm. The extreme concern of indoor pollution is that on average, people spend 90 percent of their time indoors. Studies show that human exposure to air pollutants suggest that indoor levels of many air pollutants may be two to five times (and sometimes much higher) more than outdoor levels.
This comparison tableillustrates the attributes of common residential insulation materials. The materials and their physical form that are considered are as followed: Fiberglass [blanket], Cellulose [blown], Mineral Wool [blown], and Cotton (Denim) Batts [blown]
Costs are displayed in relation to square footage, and may vary, depending on the thickness used. Installation costs are not displayed in this table.
- There are many factors that determine the total cost of a contractor installing insulation, but an estimate to insulate an open attic to modern standards is approximately $0.50 -$2.25 per square foot.
- Depending on local climate and the R-value of the materials the customer desires, it will cost anywhere from $400 to $1,800 insulate an 800 square foot space. This space with a typical attic insulation averages $750 to $1,100.
- Do-it-yourself materials for roll-out batting in an open attic can cost $100 to $500, depending on desired R-values, size, and other factors.
|Materials||Costs (sq. foot)||R-Value [ft²·°F·h/Btu] (per in.)||Pollution from Manufacture||Formaldehyde Emission Rate (µg/g/day)|
|Fiberglass||$0.70||3.7||Formaldehyde emissions and energy use during manufacture||0.3-2.3|
|Cellulose||$1.20||3.5||Vehicle energy use and pollution from newspaper recycling||ND|
|Mineral Wool||$2.40||3.1||Formaldehyde emissions and energy use during manufacture||ND|
|JM Fiberglass insulation||$0.35||.86||Energy use during manufacture||None|
- ND= Not detected
- JM= Johns Manville (Formaldehyde-Free Fiberglass insulation batt)
- R-value is given per inch (e.g. if a material had an r-value of 3.7 per in., to achieve a level of R-13 for a wall, less than 4 inches of material would be needed)
The R-Value describes the rating given to a material based on the its' ability to retain heat. There are two different units used to describe R-value. The first is SI units (m²·°C/W), and the second United States customary units (ft²·°F·h/Btu). The scale of R-value refers to how much insulation has been laid and of what material. The amount of R-value needed for a residence depends on the climate of the area, and the types of weather conditions common to that area, such as high winds. The necessary R-value also depends on what area of the house is being insulated; for example, roofs have different minimum R-values than walls or heated slab floors do. Each state has Mandatory Insulation Requirements for the state, and it's varying climate areas, so requirements vary greatly (even within the same state). To put R-value in perspective: Insulation for an attic in California must be a minimum of R-38 in zones 1-15, and R-30 in zone 16. And Insulation for walls must be a minimum of R-13 in all zones.
Manufacturers of Fiberglass Insulation[edit | edit source]
Greenguard is an environmental institute that protects human health by reducing exposure to toxic chemicals and improving indoor air quality. They are a third-party that researches product emissions to determine the appropriate levels of emissions for each product. The aim of this environmental institute is to determine which processes and products have low chemical and particle emissions for indoor use. By doing this, they want to reassure the consumer that they are buying a safer, and more vigorously tested product. Greenguard then certifies products that have low emissions and puts this mark on the product to inform the consumer that it is certified by the company: 
|Ark-Seal, Inc. Int'l.||No|
|Knauf Fiber Glass||Yes|
Alternatives to Fiberglass Insulation[edit | edit source]
- Cotton Batts (Denim):
UltraTouch is a company that produces this product. It is made almost entirely from 100% recyclable natural denim and cotton fibers, and compared to other types of insulation, it requires a minimal amount of energy to make. It contains no VOC's or chemical irritants and needs no carcinogenic warning labels. These recycled cotton batts are fire-resistant because they are treated with a natural fire retardant that also acts as a pest, mold, and mildew protector. Not only is it a better alternative for the environment, but it maintains a high R-value of at least 8.
- Mineral Wool:
On average, mineral wool contains 75% post-industrial recycled content. It can be used in blanket or loose-fill form and does not need extra chemicals to make it fire resistant. Softer batt mineral products are created that are more dense, fit in standard wall cavities tighter, and are less prone to air convention thermal losses than standard fiberglass batt.
- Cellulose Loose fill:
It is sprayed into closed walls and places that aren't easy accessible, for example, it works well in existing walls that you don't want to open up completely. A negative quality of this type is that it tends to settle, which leaves some areas uninsulated.
- Sprayed Polyurethane Foam:
Spray-in-place foam that is sticky and expands to fill the entire wall cavity. It is more costly than the other types of insulation, but has a much higher R-value because it expands to all the little nooks in the provided area. Avoid Foam with CFC's.
- Recycled Newspapers:
Paper has superior insulating properties to fiberglass and mineral wool if it is protected from dampness and properly treated with borax to make it fire and insect resistant. It can be installed by hand filling or spray blowing it into place.
- Soy-based Foam:
Foam insulation that is made from soy and is much healthier than spray foam, but has all of the same benefits of it.
- Rigid Foam Board:
Stiff boards of insulation used at edges of concrete slabs used in tight spaces. It is more expensive, but rigid boards get higher R-value. Avoid products with formaldehyde
- Perlite (loose-fill):
Perlite is used as a loose-fill insulation in construction. It is an outstanding insulator and is light weight. It is applied by pouring perlite into cavities of a concrete block and it fills out all the cores and crevices completely. Perlite also enhances fire ratings, reduces noice, and is rot and insect resistant.
Do Fumes From Fiberglass Insulation get into Indoor Air?[edit | edit source]
Sometimes after installing insulation an odor is detected. There are two types of odors that can come from fiberglass insulation. The first is a petroleum smell that can be detected more easily in insulation products that were recently manufactured. The odor will generally subside within a few days and should not return once it is gone. To speed the removal process of the odor you can ventilate the area. The second odor is very uncommon and smells fishy or urine-like. This odor is caused by binder that was not baked off or cured in the manufacturing process. This odor should also dissipate, but not as quickly. The amount of time it takes to dissipate depends on the amount of binder that was left over. Similar to the first type of odor, the second odor can be eliminated more rapidly with ventilation.
Materials that contain fibers such as fiberglass composite materials or insulation can irritate the skin, eyes and respiratory tract when disbursed in the air and/or inhaled.
See also[edit | edit source]
- A FEW LINKS TO OTHER RELEVANT SITES OR INFO
References[edit | edit source]
- http://web.archive.org/web/20180909042020/http://www.energy.ca.gov:80/maps/building climate zones.html
- Green Building and Remodeling for Dummies, Wiley Publishing, Inc., 2008.
- http://picasaweb.google.com/lh/photo/S1V78nQOV3VzEIKKOr a1w
- Eco-Renovation: the Ecological Home Improvement Guide, Chelsea Green Publishing Co., 1999.