Cellulose Insulation

One key to our affordable, environmentally sound, energy-saving solutions is our use of cellulose insulation materials. Cellulose is made from 85% recycled newspaper and does not conduct heat like fiberglass. It was created as an acoustical product and provides exceptional sound insulation and buffering, and it is treated with natural borates which prevents the paper from burning. When we install our products in your home, we create such an effective air barrier that it increases the amount of time you and your loved ones have to escape your home in the event of a fire, as fires require oxygen to burn. An additional benefit of cellulose is its insect-deterrent properties. For years, farmers have used the same borates we treat our cellulose with to control insects and vermin. They will not nest in AppleBlossom's treated cellulose. 

Fiber glass is made from mined products which are heated in huge gas-fired furnaces, and then blown or spun into fibrous threads.

Fiberglass insulation is a conductor of heat and energy, and as such, can conduct heat - up to 125 degrees - inside your home, making it more difficult and expensive to cool in the spring and summer. It also requires up to 10 times more embodied energy to manufacture compared to cellulose insulation.

When selecting insulation for your home, you want the best performing product available, and the one that provides you with the best value for your money. With cellulose insulation you get both great value and great performance, including the highest R-value per inch, excellent fire retardant capabilities and exceptional sound control, not to mention the fact that cellulose is one of the greenest building products in the world today.

What is Cellulose Insulation?

Building insulation is low-thermal-conductivity material used to separate the internal climate and sounds of a building from external climate and sounds. Cellulose insulation is plant fiber used in wall and roof cavities to separate the inside and outside of the building thermally and acoustically.

Four major types of loose-fill cellulose products have been developed under a variety of brand names. These are generally characterized as dry cellulose, spray applied cellulose, stabilized cellulose and low dust cellulose. These types are used in different parts of a building and for different reasons.

Dry Cellulose (Loose Fill)

Dry cellulose is used in retrofitting old homes by blowing the cellulose into holes drilled into the tops of the walls. It can also be blown into a new wall construction by using temporary retainers or netting that is clamped in place then removed once the cellulose has reached the appropriate density. This form of application does settle as much as 20% but the stated R-value of the cellulose is accurate after settling occurs. In addition, a dense-pack option can be used to reduce settling and further minimize air gaps. Dense-pack places pressure on the cavity, and should be done by an experienced installer.

Spray Applied Cellulose (Wet-Spray)

Spray applied cellulose is used for applying cellulose to new wall construction. The only difference is the addition of water to the cellulose while spraying. In some cases the insulation might also mix in a very small percentage of adhesive or activate a dry adhesive present in the cellulose. Wet-spray allows application without the need for a temporary retainer. In addition, wet-spray allows for an even better seal of the insulated cavity against air infiltration and eliminates settling problems. Wet-spray installation requires that the wall be allowed to dry for a minimum of 24 hours (or until maximum of 25% moisture is reached) before being covered.

Stabilized Cellulose

Stabilized cellulose is used most often in attic/roof insulation. It is applied with a very small amount of water to activate an adhesive of some kind. This reduces settling and decreases the amount of cellulose needed. This can prove advantageous at reducing the overall weight of the product on the ceiling drywall helping prevent possible sag. This application is ideal for sloped roofs and has been approved for 5:12 (41.66%) slopes.

Low-Dust Cellulose

The last major type of cellulose insulation on the market is low dust variety. Nuisance levels of dust are created during application of most types of dry insulation causing the need for simple dust masks to be worn during installation. This kind of cellulose has a small percentage of oil or similar dust dampener added. This may also be appropriate to homes where people are sensitive to newsprint or paper dust (though new dust will not be created after installation).

Advantages of Cellulose Insulation

Often Times, the Simplest and Most Natural Solutions are the Best: Cellulose is the oldest form of building insulation.

For centuries, cellulose materials such as newspaper, cardboard, cotton, straw, sawdust and corncob have been used as insulation. The Monticello residence designed and built by Thomas Jefferson was insulated using cellulose.

Today’s Cellulose Insulation

Modern cellulose insulation is made with approximately 85% recycled paper fiber and post-consumer waste newsprint. The other 15% is typically boric acid (mineral name Sassolite) commonly used as an antiseptic, insecticide and flame retardant. Sassolite is found in volcanic areas like Tuscany and Nevada. 

Recycled Materials and Embodied Energy Used for Insulation

Cellulose has the highest recycled content of any insulation available. For example, fiberglass has a maximum amount of 30% recycled content. Embodied energy is the energy required to make the product, bring it to market, and dispose of it. The embodied energy of cellulose compared to other insulation is the lowest. Furnace-made insulation requires up to 40 times more energy to produce as compared to cellulose. Cellulose is made with locally available materials with the exception of the fire retardant.

Cellulose is Considered to be “Green Insulation”

Cellulose insulation is recognized by the US Green Building Council certification program and using cellulose can help obtain LEED credits. Cellulose insulation can earn LEED credits in two categories:

• Energy and atmosphere energy performance category.
• Materials and resources recycled content category.

Thermal Performance of Cellulose Insulation

The thermal characteristics of cellulose compares favorably to other types of insulation. Cellulose surrounds items behind drywall such as pipes and wiring. It leaves few air pockets that can reduce overall wall efficiency. When installed properly, cellulose can seal walls from air infiltration. Compared to foam insulation, cellulose has a lower R-value per inch, but is much less expensive, is not made with toxic chemicals and does not release toxic fumes when burned.

A study conducted by The University of Colorado compared two identical structures – one with cellulose and the other with fiberglass. The structure with cellulose tightened the building envelope by 26.4% and the study also suggested that the overall energy performance improved by 38%.

The thermal performance of loose filled cellulose compares favorably to other types of insulation. The thermal conductivity of loose-fill cellulose is approximately 40 mW/(K*m) (an R-value of 3.8 per inch) which is about the same as or slightly better than glass wool or rock wool. This doesn’t represent the whole picture of thermal performance. Other important aspects are how well the building envelope is sealed from air infiltration, convective airflows, and thermal bridging.

Cellulose is very good at fitting around items in walls like pipes and wiring leaving few air pockets that can reduce the overall efficiency of the wall. It also seals walls from air infiltration while providing the density to limit convection. The University of Colorado School of Architecture and Planning did a study that compared two seemingly identical test structures, one with cellulose and the other with fiberglass. The cellulose structure had used 26.4% less energy to heat. It also was shown to tighten the structure more than 30%. Subsequent real world surveys have cellulose performing 20-30% better at reducing energy used for heating than fiberglass.

Compared to foam insulation, cellulose has a lower R-value per inch, but is much less expensive; foam has a higher cost per equivalent R-value.

Long-Term Cost Savings

Cellulose's insulation qualities "can save homeowners 20 to 50 percent on their utility bills".

Sound Insulation

Noise reduction is achieved in three ways with cellulose. The first is that cellulose completely fills cavities leaving few air pockets for sound to travel in. The second is the cellulose materials ability to trap air. The significant difference between noise reduction with cellulose and fiberglass is its density. Cellulose is approximately three times denser then fiberglass. This helps deaden the sound through walls and between floor levels.

Several installation options allow walls to have a Sound Transmission Class (STC) of 50 or greater. As a comparison, walls with fiberglass batts have an STC of 36-39, depending on stud and screw spacing.

Mold and Pest Control

The borates in cellulose insulation provide superior control against mold, insects, and pests such as rodents. Installations have shown that even several months of water-saturation and improper installation did not result in mold.

Fire Retardation

The borate treatment also gives cellulose the highest (Class I) fire safety rating. Many cellulose companies use a blend of ammonium sulfate and borate. Although ammonium sulfate is normally odorless, unexplained emission of ammonia and a resulting ammonia smell has been found in some cases.

Vapor Barrier

A vapor barrier may not be needed with cellulose insulation. For example, recent studies have shown that air movement is the primary method by which excessive moisture can accumulate in mild marine climate such as Portland, OR, USA. An insulation that fills the wall cavity completely (such as cellulose or foam) can help prevent moisture problems. Recommendations against using vapor barriers with cellulose insulation are supported by studies, even though they classify cellulose as vapor permeable.

In addition, cellulose acts to distribute moisture throughout the cavity, preventing the buildup of moisture in one area and helping to dry the moisture more quickly. Cellulose manufacturers do not recommend the installation of a vapor barrier with cellulose.

Dynamic Cellulose

ABI is proud to be a first insulation company in the Carolinas and Virginia offering a new generation of dynamic insulations.

This material was developed during a joint project with DOE’s Oak Ridge National Laboratory (ORNL). It is a 20% blend of microencapsulated Phase Change Material (PCM) and cellulose insulation.

As shown to the right, it doesn’t require any additional equipment to install.

What is Phase Change Material? How does it work in building envelopes?

An answer is very simple. It works in a similar way like ice in your glass of Coke:

Micro-encapsulated phase change materials (PCM’s) consist of an encapsulated organic substance with a high heat of phase change process (for example paraffin or fatty acids), which absorbs and releases thermal energy in order to maintain a regulated temperature within a product (such as clothing, upholstery, packaging and building materials).

Three years long lab and small-scale field testing, performed by the ORNL’s Buildings Technology Center and AFT on PCM-enhanced cellulose, demonstrated superior energy performance comparing with traditional insulations.

Check out the following link: http://www.ornl.gov/sci/roofs+walls/AWT/ComputerSimulations/index.htm

Thanks to collaboration with Microtek Laboratories Inc., this new insulation product is using ignition-resilient PCM.

To ensure that new insulation is in full concurrence with existing code requirements, the PCM-enhanced cellulose went through series of flammability tests passing smolder combustion testing and critical radiant heat flux test. When the PCM microcapsules are added at a 20% by weight level to blown cellulose insulation intended for installation to attic floors or walls, the product conforms to ASTM C1485-00.

Blown cellulose insulation blended with ignition-resilient PCM microcapsules doesn’t promote flame.

This photograph shows the test panel right after passing one of the flammability tests.