What's R-value?
R-value' is a measure of how well an insulation product resists the flow of heat or cold through it. R-value is determined by a laboratory test in which an insulation material is sandwiched between a cool and warm surface. The ability of the material to resist temperature changes results in an R-value for that material.

So what's wrong with that?
A machine in a laboratory gives a relative number that can be used to compare products, but a laboratory R-value does not tell everything you need to know about the effectiveness of those products. Insulation is subjected to a wide range of temperature conditions in a house. The insulation is affected by air movement, and it is also degraded by the convection forces that develop within the insulation material.

Convective Loops
Improper installation of conventional insulation, light density blown-in insulation and structural items such as a drop soffit in the kitchen can create a convective loop. A convective loop, whether inside a wall cavity or in another building assembly, occurs when air rises along a warm surface and falls along a cold surface, creating a circular movement of warm and cold air.

A convective loop transfers heat through the building assembly, requiring more energy to replace the lost heat in heating seasons and the lost cool air in cooling seasons.

Air Leakage
Building code officials, building inspectors, and many builders focus their attention on the R-values of materials to increase the energy efficiency of homes and focus their efforts on vapor retarders to prevent moisture accumulation in ceilings and walls. Air tightness is many times considered a secondary factor for keeping the heat in - or out.

However, research shows that air leakage into and out of the building envelope is a primary factor in moisture accumulation and heat loss.

Because air infiltration can account for 25% to 45% of the total heat loss in a typical home, the R-value of an insulation material alone is not a true measure of its effectiveness.

Some insulation materials, through installation, have more leaks, reducing the "Effective R-value." Nu-Wool® Insulation, when properly installed, greatly reduces air leakage - providing a superior R-value in "real world" environments, where it counts. Nu-Wool's® higher "Effective R-value" results in energy savings of up to 40%" compared to conventional insulation.

The Colorado Study
The University of Colorado School of Architecture tested the "real world" performance of cellulose and fiberglass insulation. They built two structures and insulated one with fiberglass using R-19 in the walls and R-30 in the ceiling. The other structure had the same measured R-values, but was insulated with cellulose insulation. The cellulose insulated building was seven degrees warmer than the fiberglass structure after a nine hour heat loss test. But more importantly, after three weeks of monitoring the cellulose insulated building used 26.4% less energy than the fiberglass structure. The researchers concluded that cellulose insulated buildings perform 38% better than fiberglass insulated structures. Keep in mind that both structures had the same measured R-value. The conclusion: cellulose has a higher "Effective R-value."

Nu-Wool® WALLSEAL® is a better insulation value.
Homes insulated with Nu-Wool® WALLSEAL® are generally "tighter" (without being too tight) than traditionally insulated homes. Energy usage is directly impacted by air leakage; 25% to 45% of energy usage is caused by air infiltration. Also, air movement across an insulation material decreases its R-value. WALLSEAL® does not experience R-value degradation because it virtually stops air movement within the wall. No reduction in R-value means a higher "Effective R-value," which means more insulation value for the homeowner.

Guaranteed Energy Program
Nu-Wool® has been offering guarantees on the energy performance of homes since 1987. In that time, tens of thousands of homes have taken advantage of this program. Nu-Wool® lnsulation is installed in over 18,000 homes annually in at least 15 states. Nu-Wool® Company, Inc. can offer this guarantee because the Nu-Wool® WALLSEAL® system is consistently superior to other insulation products.

How does the guarantee work?
Each home's characteristics are entered into a computer program that calculates the cost of heating and cooling based on fuel, weather data, efficiency of the HVAC system, and the air infiltration factor for that home. Nu-Wool® guarantees the homeowner that the heating and cooling costs for their home will not exceed this calculated amount for a period of 3 years. If the costs are over the stated amount. Nu-Wool will reimburse 50% of the overage. If only R-values were used in the computations, homes with Nu-Wool® Insulation would not heat any differently than homes with fiberglass. Through decreased air infiltration, Nu-Wool® Insulation has a higher "Effective R­-value." Nu-Wool® insulated homes heat and cool more efficiently than conventionally insulated homes.

Properly Sized HVAC Equipment
The higher "Effective R-value" of Nu-Wool® Insulation also means that many times the heating and cooling equipment can be reduced in size in a structure properly insulated with Nu-Wool® Insulation. Properly sized HVAC equipment is usually less expensive and operates more efficiently than oversized equipment. Nu-Wool's® Technical Services Department can properly size heating and cooling equipment using industry leading software

*R-value testing is regulated by the Federal Trade Commission. The use of R-value tests allows the consumer to make choices based on the relative values for different products.

* *Savings can vary. Find out why in the seller's fact sheet on R-values. Higher R-values mean greater insulating power.