A better sealed, ventilated & insulated building envelope by Applied Building Science will save you money on utility bills for years to come. And, by using less energy to heat & cool your home or business, you reduce the negative impacts on the environment caused by fossil fuel use.

Many homes are poorly insulated or missing insulation entirely. Applied Building Science installs high performance, eco-friendly cellulose insulation in walls, overhanging floors, and attic space to ensure the home has strong thermal protection. Our tube-in-wall Densepack method into wall & ceiling cavities delivers impressive air flow resistance and noise suppression results as well.

Insulation Levels and Types
Applied Building Science recommends using the rated R-value of particular insulation as a guide, not the determining factor. It’s only a laboratory-generated number. There are trade-off benefits; some materials like cellulose and spray or rigid foam do much better in real-world applications than fiberglass batts & loose-fill. See Effective R-value.

http://www.applegateinsulation.com/CEDocuments/Downloads_GetFile.aspx?id=290730&fd=0

http://www.southface.org/web/resources&services/publications/factsheets/12insulation.pdf

Eliminate Air leaks—then insulate
Insulation and air sealing are important parts of a home’s “thermal envelope,” which separates outside conditions from inside. This envelope consists of the components of all six sides of the home—the four walls, roof, and foundation. The most important parts from a thermal point of view are the insulation and air-sealing materials, properly installed. All the components interact together as a system to affect the flow of heat, air, moisture, and sound into or out of the home. The better the thermal envelope does its job, the better the health and comfort of occupants and the lower their utility and maintenance bills.

You may think that insulating should be the first step in making your home more energy-efficient, but consider this: Air leaks through the ceiling, walls, foundation and other areas typically are the greatest sources of heat and cooling losses in a home. Controlling air leaks is the best way to extend the life of your home, as well as to conserve energy, save money and increase your home’s comfort. The bottom line is this: If you don’t tighten up your home first, money spent on insulation may be wasted. See Air Infiltration.

Insulation can be added to an existing building envelope by filling the framing cavities (floor, ceiling and wall) or by installing an additional layer of insulation, usually a rigid board type, adjacent to the frame of the envelope. Insulation should be selected for its ability to completely cover or fill the area of placement and to provide the optimum (or Effective) R-value for the most reasonable cost. It must also be installed in accordance with all fire, electrical and safety regulations.

Insulation
Insulation of the building envelope reduces the conductive losses and gains by improving the envelope’s resistance to heat flow. This greatly improves comfort while reducing the energy demand and the size of appliances required for space conditioning. The effectiveness of insulation is dependent on the quality of the installation and the insulation’s rated ability to resist heat flow.

The R-value (or thermal resistance) of insulation is a measure of its ability to resist heat loss or heat gain. The higher the R-value, the better a material resists this flow. Manufacturer’s rated R-values refer to the insulation values under “best case” conditions when coverage is complete and without voids, the material has been installed to the proper density, and that the insulation is installed with proper and integral air and vapor barriers in place. Any deviation from these installation standards, will adversely affect the performance (R-value) of the material.

The R-Value Myth
It’s one thing to compare R-values of different insulating materials off of a chart.  But how do we measure how well insulation works?  In today’s climate of rising energy costs, should we expect more from insulation than merely resisting heat flow?

The unsuspecting (or uneducated) consumer has been rather “duped” by the insulation industry’s obsession with rated R-value. Insulation R-values are not determined in real-world environments. The manufacturer of a fiberglass batt, for example, determines the rated R-value of their product in a laboratory test under an extremely controlled setting. During the test, the batt is encapsulated and perfectly aligned in a test fixture. There is absolutely zero air flow (like a vacuum) in this simulated wall-cavity.

Furthermore, correct installation is critical if insulation is to perform to somewhere near its stated R-value. It must not be compromised by gaps or voids (a reason to avoid batt insulation). It should be encased on all six sides and must touch the surface of the side it is intended to insulate. It must not be compressed but must be dense enough to prevent air currents from passing through it (a problem with fiberglass batts and loose-fill in very cold climates).

Unfortunately, homes are not built or function in laboratory conditions. These conditions are never seen in an actual house.  Wind, climatic temperature changes, use and age can have a dramatic effect on insulation’s ability to preserve its rated R-value. There is never a vacuum inside the wall, and often times there are not six complete sides to the cavity (as in a knee wall or attic). Home construction is rife with lack of attention to detail when it comes to installing insulation correctly.

Effective R-Value
Across the nation, building performance specialists like Applied Building Science use different terminology when talking about the performance of insulation under real-world environments. More and more emphasis is being given to the insulation's resistance to airflow, not heat flow alone. The term being used is “Effective R-Value”.

Effective R-value expresses a material’s performance and resiliency to the effects of convective heat loss under which the material is used. The convection heat transfer process is powerful since it involves air movement and pressure (think of air as a liquid). Warm air always travels to cold air. In a wall, for example, air flow occurs up and down the cavity in a process called convective looping. Imagine a water-wheel inside the wall that is constantly stripping heat from the inside of the wall and dumping it in a circular motion to the colder outdoors.

Low-density fiberglass batts or loosely blown-in cellulose – that is, not Densepacked – in the wall is no match to the heat-scavenging effects of convective looping. This also means that the airflow will be magnified where insulation is installed on a subfloor, kneewall, or ceiling, because one side of the insulation is exposed to a large volume of the unheated part of the structure.

Unfortunately, there are no industry standards that measure the effective performance of insulation. It is a homeowner’s responsibility to fully understand how each component in the house affects the others, including the choice of insulation. In general, however, denser materials – either by manufacture or by installation – reduce convective heat loss and enable the material to preserve its rated R-value. Rigid foam board and spray-on polyurethane foam insulation have excellent air and heat flow resistance properties.

Thanks to its cellular and monolithic properties, cellulose insulation that is Densepacked into closed wall cavities - or wet-sprayed in open stud bays during new construction - also reduces the effects of convective losses. Also, “capping” fiberglass batt insulation in the attic with blown-in cellulose improves the efficiency of the batt due to negative the effects of convective losses at cold temperatures.

What We Use
Applied Building Science uses predominantly cellulose and polyurethane spray-on insulation in its weatherization upgrade work. We use fiberglass batt insulation sparingly because it does not possess sufficient density to restrict air movement like other materials.

Cellulose has been a pillar of weatherization practice and indispensable to the revitalization of existing buildings. As an approved contractor for DOE-funded weatherization of low-income homes, thermal renovations Applied Building Science performs to older homes typically produce startling changes in performance hen using cellulose insulation. Pre and post analysis using the blower door air infiltration test reveal a 15-60% reduction in air exchange from inside to outside the structure. This translates into reduced furnace run-time, lower energy consumption and improved occupant comfort

Cellulose insulation has many excellent features:

• 85% re-cycled
• 6 times less embodied energy used during its manufacture than fiberglass
• Will not support combustion
• Treated with borate for moisture, insect and fire resistance
• Compressible to reduce both conductive and convective heat losses (like walls, overhangs, ceilings between living space and unheated garage, etc.)
• Impressive noise suppression characteristics
• Less irritating than fiberglass fibers when air-born.

A study conducted by the University of Colorado is widely used to compare cellulose and fiberglass insulation. In that study, two houses were constructed; one had the attic and walls insulated with cellulose, the other with fiberglass. Tests showed the house insulated with cellulose was over 36% tighter and used over 26% less energy to heat than its fiberglass counterpart. See www.cellulose.org

Not surprisingly, the fiberglass insulation industry does not support this study. Had all cavities been air-tight like those found in a test laboratory, the results with fiberglass might have been different. But who lives in a test laboratory? See Insulation Myth.

Spray Foam Insulation

Pros and Cons of Open and Closed Cell Spray Foam Insulation

http://sc.leadix.com/honeywell/files/LBM%20Journal%20OC%20v%20CC%208-07.pdf

UFFI - UREA Formaldehyde Foam Insulation: Much Ado about Nothing?

http://www.carsondunlop.com/Inspectors/uffi.htm

Insulating Existing Walls
Note: It is nearly impossible to effectively re-insulate a wall that already contains batt insulation. Unless performed with surgical precision, attempting to compress more material into a cavity with batt material can create huge air pockets and reduce the thermal resistance of what is already there.

With many attics already supplemented with additional levels of insulation, homeowners are now turning to insulating walls as a means improve energy efficiency and comfort - and for good reason. According to weatherization experts, the effective leakage area in very old houses can be reduced by 40-70 percent just by tube-in-wall Densepacking cellulose insulation [Densepack Outside Photos] into un-insulated exterior wall cavities; blower door air infiltration testing by Applied Building Science before and after Densepacking supports these findings.

Applied Building Science has also found the tube-in-wall Densepacking process to be very effective in reducing convective heat losses and coldness in cantilevers such as overhanging floors and bay windows [Westphal, O’Sullivan & Dytyniak O’Hang Photos], as well as the floors of living spaces over unheated garages [Dytyniak Photos].

How does the tube-in-wall Densepacking process differ from traditional methods of insulating walls?

The traditional method consists of drilling two holes through the outside wall sheathing and into each stud cavity; each stud cavity is roughly 16 inches in width, which means holes are drilled along the entire wall.

Where aluminum or vinyl siding is present, the siding is “unzipped” to expose the sheathing. In the case of brick veneer, holes are drilled though the mortar joint and sheathing. A hose or nozzle is inserted into the hole. Cellulose insulation is injected at high velocity into the stud cavity. When material ceases to flow, the cavity is judged full. The process is repeated for the 2nd hole in the cavity, followed by the remaining cavities along the wall. Once completed, the siding is re-zipped or the mortar joint filled with grout.

What’s the problem with the traditional method? There are many: [Turman House & Wall Photos]

1. It is essentially a blind operation. There is no visual or tactile means of assessing much or how far the insulation actually traveled. There is also no means of determining if an obstruction is present in the cavity.
2. The velocity at which the insulation is injected into a hole drops dramatically as it slams into the interior wall. This explosion transforms the dense mass of injected material into a sort of “pixie dust”. This is particularly acute in installations through brick when using a very small (1/2”) diameter nozzle.
3. Gaps and voids begin to form (especially around electrical wiring) as the cavity fills with buoyant cellulose. At some point, the material ceases to flow at the point of injection, rending the cavity “full”.
4. At this stage the material has little density to remain cohesive. Over time, the material settles, causing insulation gaps at the top of the cavity.

Sadly, even the latest technology such as infrared Themography may not detect the significance of the gaps. Since infrared technology relies on measuring surface temperature, even trace amounts of insulation in an otherwise porous section can appear as having some material present.
 
What’s different with the tube-in-wall Densepack method?

1. Inserting the tube up or down the wall cavity –as opposed to aiming a nozzle at it – enables the installer to gauge the height of the cavity as well as any obstructions. An additional hole can then be drilled above the blockage.
2. The velocity of the material being injected is directed against the top or bottom of the cavity as well as against itself. The velocity remains constant until the material around the hose is fully compressed.
3. Retracting the hose incrementally continues to compress material into the spaces being displaced until the entire cavity is filled.
4. Gaps and voids are virtually eliminated since the compression process transforms the material into a consistent density of exceptional mass throughout the cavity. Installed densities greater than 3.0lbs/ft3 assure that settling will not occur.
5. Densities of installed material can be easily calculated by comparing bag weight to the area being insulated.  

The tube-in-wall Densepack method cannot be performed from the outside with brick veneer or stone due to the size of the hole required for the operation. In these cases, Applied Building Science can insulate the walls from inside the structure, then re-finish the drywall or plaster wall surface at each cavity. Special vacuuming equipment is used to minimize air-born dust created during the process.  The collateral benefits of performing the tube-in-wall Densepack method far outweigh the short-term inconvenience in the living space.

Dense Pack Cellulose Insulation – The Process
“When cellulose is pneumatically installed at high velocity to densities greater than 3.5 pounds per square foot, it acquires a unique air sealing property. In this process, the material behaves as a liquid, flowing into obscure bypasses and solidifying them. DP solves air movement problems critical to building performance that would be impractical to access or repair in any other way. So it is a pillar of weatherization practice and indispensable to the revitalization of old buildings.

Building cavities subjected to wind, stack, or mechanical pressure move enormous amounts of conditioned air. Common insulation methods do little to stop this flow, so the insulation performance is degraded, and the larger convective heat losses continue. DP forms a perfect injection molded block in these cavities that stops the air movement and delivers real control of conductive heat loss too.

Tolerance to compaction is a critical property of cellulose. Unlike mineral based insulations, organic fiber is cellular in nature and inherently non-conductive. Trapped air is only one part of its insulating ability. Compacting cellulose insulation would ultimately reduce its R-value to that of wood. If we compact fiberglass to the same degree, we would get the insulation performance of glass. When we need to get air sealing by tightly packing insulation, cellulosic fibers such as cotton and paper retain there resistance to conduction and mineral fibers don't.

Building cavities are dense packed by inserting a pipe, tube, or hose down the entire length of the passage. A powerful insulation blower delivers a lean mixture of cellulose and air at about a hundred feet per second. Initially the cavity is pressurized with a cloud of insulation. The air flows out through every crack and pinhole carrying fine particles of insulation. The holes are clogged with insulation until they stop flowing and the cavity fills with a loose pile. Then the cellulose chunks charging down the tube start to slam into the loose pile and pack it. When it becomes very tight, it plugs the end of tube and stalls the insulation blower. The tube is quickly pulled back until the tip finds more loose insulation. The flow and packing process starts again and this continues until the entire cavity is solid.

Now this part of the building shell is an efficient part of the thermal envelope. The area is insulated to a real R-3.8 per inch because there is a real pressure barrier built into the assembly to stop air flow and protect the insulation.

Thermal renovations to old buildings typically produce startling changes in performance. The effective leakage area in old houses is typically reduced by 40-70 percent just by dense packing the hidden framing bays. This results in actual ventilation reductions of 50-90%. Tremendous fuel reductions result. But the collateral improvements are often more important. Buildings that were formerly impossible to heat now become stable, comfortable and highly efficient living and working spaces.

Dense-packing the Cornwall Congregational Church, Cornwall, Vermont
Thermal revitalization is fundamental to the historic preservation of old buildings. DP is an invisible and completely reversible process. With no diffusion barrier to trap moisture, it helps to preserve the shell of the building. Cellulose fiber is highly absorbent and actually wicks moisture content out of framing members. The pack imparts an enormous moisture storage capacity to the shell. This stabilizes the interior plaster and exterior paint by buffering the water load forced into the shell through the heating season. And by blocking all the paths for warm, moist air to blow into the framing spaces, they are relieved of 98% of the load right from the start.

DP insulation is an important element in fire safety. Typically, fire destroys wood buildings by entering and traveling through the framing bays. Once walls start to act like chimneys, the studs are quickly consumed. Blocking or fire stops are known to be effective in preventing the spread of fire from floor to floor and ultimately into the attic. DP behaves as continuous blocking in walls because the framing is really solid. In fact, test buildings with DP walls are virtually impossible to destroy by fire.

Not all buildings are good candidates for insulation including DP. Insulation should not be placed in contact with the soil, exterior masonry, unrated lighting fixtures, obsolete wiring, unlined or deteriorated chimneys, or leaking pipes and roofs. In general, all of the structural and mechanical defects must be repaired before a building is insulated.

Extra care must be used when installing high speed insulation. As the tube is withdrawn from the access hole, cellulose will blow back and pack your eyes, nose, mouth, and ears before you can blink or hear yourself swear. We mark the end of our houses a foot from the end so that we can slow down and block the flow with a rag.”

Re-printed from http://www.weatherization.com/densepack.html