Insulation materials are rated according to their ability to resist heat flow. The thermal resistance rating is known as an “R-value”. The higher the R-value of a material, the better its ability to resist heat flow.
Most new homes are insulated with fiberglass batt insulation. However, improper installation of the fiberglass batts can significantly reduce its effectiveness. Gaps or voids can provide paths through which heat and air can easily flow into or out of the home. Compressing the insulation behind piping and electrical wiring also reduces the thermal resistance.
Newer types of insulation like blown-in-blanket fiberglass, batts made of denim, blown cellulose, and spray foams have higher R-Values and protect against convective heat transfer because they penetrate around obstructions and into odd-shaped cavities, completely filling gaps or voids and providing a monolithic blanket of insulation that forms a tight seal around wiring, plumbing, and framing materials.
Benefits of improved insulation
Improved insulation provides:
Improved insulation reduces conductive heat losses and gains resulting in warmer interior surfaces in the winter and cooler interior surfaces in the summer. As noted in my article on advance framing, approximately 40 percent of our physical comfort is due to the radiant heat exchange between our bodies and the surrounding interior surfaces. Improved insulation reduces this radiant heat exchange and minimizes temperature differences between rooms, thus maintaining a more consistent level of comfort throughout a house.
Improved indoor air quality
When insulation materials are properly installed, there are fewer gaps and voids through which unconditioned air can leak into a house. This helps avoid dirt, dust, and other impurities that can negatively affect indoor air quality. A tight building envelope is a critical component to ensure good indoor air quality.
Reduced heating and cooling loads
Improved insulation also helps to reduce heating and cooling loads, allowing smaller “right-sized” heating, ventilation, and air-conditioning (HVAC) systems. The cost savings from using smaller HVAC equipment can be used to offset the additional cost of high efficiency heating and cooling equipment.
Lower utility bills
More than 40 percent of the energy consumed in a typical household goes to heating and cooling. Proper insulation reduces this energy consumption which results in lower utility bills.
Chuck Miller GMB CGB CGP MIRM CMP MCSP CSP
President / Builder – Chuck Miller Construction Inc.