The word cellulose comes from the French word cellule, for living cells, and glucose, which is sugar. Building insulation is a low thermal conductivity material used to reduce the loss and heat recovery of buildings, and reduce noise transmission. Cellulose isolation is a plant fiber used in walls and roof cavities to isolate, prepare evidence and reduce free noise.
Video Cellulose insulation
The history of cellulose isolation
Cellulose is one of the oldest building insulation materials. Many types of cellulosic materials have been used, including newspapers, cardboard, cotton, straw, sawdust, hemp and corn cobs. Monticello is isolated with a cellulose form. Isolation of modern cellulose, made with recycled newspapers using milling and dust removal machines and added fire retardants, began in the 1950s and began to be used generally in the US during the 1970s.
The market for insulation increased following the 1973-74 oil embargo. Embargo causes energy costs to warm up soaring across the nation, leading to increased interest in energy conservation measures. Isolation gained significant national attention as a cheap and available technology to improve home energy efficiency. In 1977, after a very severe winter, tax credits were granted to homeowners who installed insulation.
While in 1976 there were about 100 companies of cellulose insulation with 125 plants, in 1978 there were more than 350 companies with more than 500 plants 1 . Cellulose isolation is produced locally by small manufacturers who buy ready-to-operate machines and offer low-cost, low-tech manufacturing processes. In addition to some of the constraints created by the lack of boric acid to be used as fire retardants, cellulose captures an increase in market share due to lower costs and suitability for retrofits. Meanwhile, fiberglass and rockwool manufacturers have difficulty meeting demand for isolation from their customers.
Due to complaints by retailers, contractors and consumers regarding pricing issues, security and quality control, the federal government began to impose isolation standards beginning in 1978. There is great concern that growth in cellulosic manufacturing leads to improper or inadequate isolation of fire threats even though statistics can not nationally reliable. This led to the Federal Consumer Product Safety Commission issuing 16 CFR Section 1209, which established safety standards that included four product attributes for cellulose isolation alone: ​​sedentary density, corrosion, critical radiation flux and burning combustion. Another approved rule is the "Rule Value-R", which places clear restrictions on claims that manufacturers and marketing companies can make about their products.
The effect of regulation by CPSC puts most of the small manufacturers of cellulosic isolation out of business. Costs incurred by increasing fire testing make cellulose more expensive and bad publicity helps lower demand. They can not meet the testing requirements or they join other small manufacturers. In 1985 the CPSC requested Congress to lift standards for flammability after further study. In 1991 only 61 cellulose producers remained in the US.
Meanwhile, the fiberglass industry benefits from most of the regulations passed by the federal government. The heavy lobbying by more centrally located fiberglass and mineral insulation manufacturers helps meet the harsh standards of fire for cellulosic isolation. These standards are reinforced by a technical bulletin published by the Association of Minerals Insulation Manufacturers (currently known as the North American Association of Isolation Manufacturers) that promote the claim of fire hazard to cellulosic isolation. These claims are not independently verified, face little scientific review, or are deliberately misleading and incorrect.
Currently cellulose insulation has increased again used in the United States. Part of the reason for this growth can be attributed to studies suggesting that cellulose can actually protect buildings from damage in flames better than fiberglass because cellulose is more dense and limits the oxygen needed to burn structural members. Several studies of the Canadian National Research Council have supported this claim. Another major reason for the cellulose comeback might be due to increased interest in green building. Cellulose has the highest recycling content of any insulating material and also has less material energy than fiberglass and other furnace-produced mineral insulations.
Maps Cellulose insulation
Producing
Cellulose isolation is often made by waste hammer milling paper. The paper is treated with chemicals, such as boric acid, to slow the spread of fire.
Products
Four main types of loose-fill cellulose products have been developed under various brand names. It is generally characterized as dry cellulose, spray cellulose, stable cellulose, and low dusty cellulose. This type is used in different parts of the building and for different reasons.
Dried cellulose
Dry cellulose is used in the retrofit of old homes by blowing cellulose into a hole drilled into the top of the wall. It can also be blown into the construction of a new wall using a temporary retainer or a net clamped in place then removed after the cellulose has reached its corresponding density. This form of application completes as much as 20% but the declared value R of cellulose is accurate after precipitation occurs. In addition, the solid packet option can be used to reduce precipitation and minimize air gaps further. The dense-pack puts pressure on the cavity, and should be done by an experienced installer.
Loose filling walls is an ancient technique using cellulose in the cavity walls. The home-performance industry and its accrediting bodies support a solid standard of insulating wall cavities, which do not precipitate. This method stops the effects of the heap and the convective loop inside the wall cavity. Spray-applied cellulose (wet cellulose spray)
Cellulose spray is used to apply cellulose to new wall construction. The difference is the addition of water to cellulose during spraying as well as adding some type of moisture resistant such as chlorine to prevent mushroom culture. In some cases insulation may also be mixed in a very small percentage of adhesives or activate the dry adhesive present in cellulose. Wet spray enables applications without the need for a temporary retainer. Additionally, wet sprays allow for a better seal of insulated cavities against air infiltration and eliminating precipitation problems. Wet spray mounting requires that the wall be left to dry for at least 24 hours (or until a maximum of 25% moisture is reached) before closing.
Stable cellulose
Stable cellulose is most commonly used in loft/roof insulation. This is applied with very little amount of water to activate the adhesive of some kind. This reduces precipitation and decreases the amount of cellulose required. This can prove to be beneficial in reducing the overall weight of the product on the drywall on the ceiling helping to prevent the possibility of sagging. This application is ideal for sloping roof and has been approved for 5:12 (41.66%) slope.
Low dusty cellulose
The main type of cellulose isolation that is last on the market is the low dust type. The level of dust disturbance created during the application of most types of dry insulation causes the need for simple dust masks to be worn during installation. This type of cellulose has a small percentage of the oil or similar dust reducer added. This may also be appropriate for homes where people are sensitive to newsprint or paper dust (although new dust will not be made after installation).
The advantages of cellulose isolation
Thermal performance
Loosely packed cellulose thermal performance is better than other low-cost insulation types, but lower than polyurethane and polyisocyanurate foams. The loose-filling cellulose thermal conductivity is about 40 mW/mÃ, Â · K (R-value: metric R2.6 per 100 mm, imperial R3.8 per inch) which is almost the same or slightly better than wool or wool glass. This does not represent the whole picture of thermal performance. Another important aspect is how well the building envelope is sealed from air infiltration, convective airflow, and thermal bridging.
Cellulose is very good around things on the wall like pipes and wires, leaving some air bags that can reduce the overall efficiency of the walls. Solid cellulose packages can seal the walls from air infiltration while providing density to limit convection, when installed properly. The University of Architecture and Planning School of Colorado conducted a study comparing two seemingly identical test structures, one isolated with cellulose and the other with fiberglass. Cellulose isolation loses 26.4% less heat energy over time compared to fiberglass insulation. It was also shown to tighten the structure by more than 30%. The next real-world survey has cellulose that produces 20-30% better in reducing the energy used for heating than fiberglass.
Compared to closed cells, Polyurethane foam insulation (R = 5.5 to 6.5 â € <â €
The annual savings from isolation vary greatly and depend on several factors, including insulation thickness, original wall performance, local climate, use of heating/cooling, airtight other building elements and so on.
One installer claiming cellulose insulation "can save homeowners 20 to 50 percent on their utility bills".
Sound insulation
Isolation reduces the sound that passes through walls and between floors. Cellulose provides mass and damping. It reduces noise in 2 ways, reduces the lateral movement of sheetrock and weakens the sound path along the cavity. Cellulose is about three times denser than fiberglass, providing a slight increase in sound reduction.
Pest mold and control
Borate in cellulose isolation provides additional control of the fungus. Installation has shown that even months of water saturation and improper installation do not produce mold.
It is a common misconception that the presence of a crude borate in cellulose isolation provides a property of pest control to the product. While boric acid itself kills insects that cleanse themselves when ingested, it must be presented to the insects in sufficient concentration and in an edible form to attain insect mortality. Appropriate testing of borate-containing products should be made to determine whether doses and presentations are sufficient to kill insects. Once tested, registration with EPA as a pesticide is required before the product can be cited to have US pesticide capability.
Flame retardation
The borate treatment also provides the highest fire safety rating (Class I) of cellulose. Many cellulose companies use a mixture of ammonium sulfate and borate.
Steam barrier
A vapor barrier may not be required with cellulose isolation. For example, recent research shows that air movement is the main method where excessive moisture can accumulate in mild sea climates such as Portland, OR, USA. Isolations that fill the full wall cavities (such as cellulose or foam) can help prevent moisture problems. Recommendations on the use of vapor barriers with cellulose isolation are supported by research, although they classify cellulose as permeable vapors.
In addition, cellulose acts to distribute moisture throughout the cavity, preventing moisture buildup in one area and helping to drain the moisture faster. Cellulose producers do not recommend the installation of vapor barriers with cellulose.
Most US city codes will require a steam barrier for any external wall. Most cities in the US will consider appealing terms if the exact reason is given. In March 2008, the city of Portland in the US, Oregon, approved an application to ignore requirements for vapor/retarder barriers when using cellulose insulation. Appeals can be found on the search form of the Portland Development Services Bureau by searching for an appeal ID 4996. Fundamental to any appeal says that recent studies show air movement is a major problem for steam, it is an effective barrier to air movement, and the cellulose serves to spread steam.
Disadvantages
R values ​​of 3.6 to 3.8 per inch are good but not the best. Material cost per R-value is good but labor costs go up because it requires more material and time to install than fiberglass insulation on the same R-Value.
Dust
Cellulose contains small particles that can be blown into the house through an inadequate seal around the fixture or small opening.
Installation expertise and building codes
In some areas, it is difficult to find an experienced installer with cellulose. An experienced installer understands how to properly pack a dry loose sheath, how best to use stable (partially wet) cellulose on a sloping surface, and the right time to spray wet cellulose.
As with any other non-batt insulation, US cities and regional/state building codes may not be updated for cellulosic isolation. Homeowners must call the city to verify that the insulation will be approved, and it may be necessary to provide product specifications to the city. This is not difficult, and installers and manufacturers should be willing to handle this process, saving homeowners every right effort.
Slide
If improperly installed, loose cellulose content may precipitate after application. In some situations this can leave an uninsulated wall area. With proper training in mounting methods and quality control techniques, this is ruled out by installing to a proven density preventing future settlement.
Weight
For the given R value, loose cellulose weighs about threefold per square foot as a loose fiberglass. The structure of the ceiling should be checked for signs of weakness before selecting the material to isolate the ceiling of the existing structure.
Offgassing
Many cellulose companies use a mixture of ammonium sulfate and borate for flame retardation. Although ammonium sulfate is usually odorless, unexplained ammonia emissions and the resulting ammonia odor have been found in some cases.
Mold
There is some evidence of an increase in fungal infestation in buildings insulated with wet solid cellulose wet sponges especially when used with a vapor barrier.
Nature of nature
Isolation of any type helps make the building more energy efficient. Depending on the structure and the manufacturer, using cellulose isolation may contribute to obtaining LEED credit from the US Green Building Council certification program.
Recycled content
Cellulose comprises 75-85% recycled paper fibers, usually post-consumer paper waste. The other 15% are fireproof such as boric acid or ammonium sulphate. Cellulose has the highest recycling content of any available insulation. For example, fiberglass has a maximum of 50% recycled content.
Low toxicity and environmental impact of raw materials
Non-recycled components of cellulosic insulation are still more environmentally friendly for foam insulation materials. Unlike foam insulation, many use HFC or HCFC blowing agents that have a higher global warming potential than carbon dioxide, cellulose does not produce significant gas emissions.
The toxicity of insulating type raw materials is usually highest during manufacture or installation. There is no significant problem with cellulose.
OSHA states that cellulose is a dust problem, requires a dust mask during installation.
Embedded energy
The cellulosic isolated enzyme energy is the lowest of the popular type of isolation. It takes 20 to 40 times more energy to produce an artificial furnace insulation material than cellulose. Cellulose is made by electrically powered engines while mineral insulation is made in a powerful fuel-fired furnace, reducing this gain to some extent, because electricity generation is less than 50% efficient. Cellulose is made with locally available paper, while mineral insulation factories transmit materials and products to longer distances.
Cellulose isolation uses borate for flame retardation. Borat is a non-renewable mine product.
References
External links
- The Association of Cellulose Insulation Manufacturers
- The Australian Cellulose Insulation Manufacturers Association
- CIMA Technical Bulletin # 2: Standard Practice for Installing Cellulose Building Insulation
Further reading
Source of the article : Wikipedia
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