Five factors affect the prevention of heat’s movement:
- Thermal bridging
- Density of materials used
- Amount of air leakage
- Amount of moisture
- Mass of the whole insulated system
When each of these factors is taken into consideration, your insulated home’s R-value will increase substantially, saving you both energy and money.
Thermal bridging is rapid heat movement through conductive building materials such as wood, steel, and aluminum. Often found in the framework of homes, these materials quickly transfer heat across barriers that are not insulated. This leads to heat loss in your home in the winter and heat entry in the summer.
You can reduce thermal bridging by using fewer conductive framing materials, and applying insulation. Installing insulation to protect against thermal bridging does not require any large changes to your home. It increases the R-value without interrupting your home’s frame and it’s an easy way to stop thermal bridging.
The density of the insulation directly affects how well the insulation does its job. Each insulating material should be should be installed at an ideal density in order to increase the R-value. For example, cellulose‘s R-value is maximized when it is installed anywhere between one and two pounds per cubic foot. Professionals know how to control the insulation’s density so that it is installed at the best R-value.
Air sealing is important for increasing a home’s R-value, but insulation also plays a part in stopping air leakage. It is important to stop airflow between inside air and outside air because air carries heat (a process known as convection). The air can take heat from one surface and convect it to a neighboring surface. This takes heat from where it is wanted and moves it to the other side of the barrier.
Without proper installation, air can leak through gaps in the insulation. Loosely installed insulation leaves a lot of space for air to travel, taking heat away. When insulation is installed at the ideal density, it does not allow airflow and in effect the system’s R-value goes up.
Air not only carries heat, but it can also carry water. Water vapor travels through the air and leaks into insulation. When this happens it cannot only damage the insulation, but it can corrode metals and supply water to insects that can destroy your home. Water is a much better conductor of heat than air, so it brings more heat across the barrier. When insulation is properly installed to prevent air leakage, it will also stop water vapor from decreasing your home’s R-value.
The thermal mass effect looks at how the mass of the building components, especially the walls, affects heat flow. It uses the estimated R-value of the mass of the components and combines that value with the R-value of the insulating system. Generally, a building with a higher mass has a higher R-value and a higher overall ability to block heat flow.
Insulation is primarily guided by R-values. R-values determine the thermal resistance across a barrier (how much heat flow the barrier blocks). The higher the R-value, the higher the amount of heat blocked from moving across the barrier. When insulating, the R-values of each system are carefully looked at in order to maximize each one. The overall goal of insulation is to increase the total R-value in your home.
We’re aware of the many factors it takes to reach your ideal R-value. We carefully look at how to get the greatest thermal resistance by looking at all aspects of your home while insulating. Call or contact us if you have any questions about these five factors, and how they affect your home.