Your home’s energy efficiency is dependent on a number of factors including the age and type of construction and type of heating and cooling system. Regardless of these factors, however, the key to attaining the maximum energy efficiency potential of your home or workplace is achieving the proper balance between four critical areas:
- Insulation
- Moisture Control
- Air Sealing
- Ventilation
In this post, we will discuss insulation and moisture control. We’ll cover air sealing and ventilation next time around.
Insulation
Having the proper type and amount of insulation will make your home more comfortable and help you reduce your heating and cooling costs by improving moisture control and reducing heat flow.
Heat flow is the natural phenomenon that causes warmer air to flow to cooler spaces. In cooler months, heat flow causes warm air to flow from living spaces to adjacent, unheated areas including attics, basements and garages. Heated air can also move indirectly through flooring, walls and ceilings. During warmer months, heat flow is reversed as warmer air moves from exterior areas to the home’s interior.
Different types of insulation have different R-values. An R-value refers to the insulation’s thermal resistance to heat flow and is dependent on the type of specific type of insulating material, its thickness and density. The higher the R-value, the higher the insulation’s thermal resistance potential.
It’s important to remember that the actual heat flow resistance is dependent on a number of other factors besides the R-value. Insulation that is improperly installed, or that becomes compacted or damp will not perform to its full potential.
Moisture Control
Moisture control is another key element in reducing your heating and cooling costs.
The ideal moisture control strategy for your home or workplace depends on the climate and type of building construction. In order to devise an effective moisture control strategy, you must first understand how moisture moves through a structure.
Moisture moves through your home in three primary ways:
- Heat transfer
- Diffusion through building materials
- Air currents
Moisture transfer via diffusion and heat transfer occur slowly, while moisture migration via air currents can happen quickly. And air currents account for more than 98 percent of moisture transfer in a typical structure. Moisture transfer is also affected by temperature and relative humidity. Higher outdoor temperatures and relative humidity lead to an increase in moisture transfer within your home.
In most areas of the U.S., vapor diffusion retarders can be effective at reducing moisture migration in attics, basements and crawl spaces, and through slab-on-grade flooring and walls. You must also ensure that your home or workplace is properly ventilated in order for your moisture control strategy to be effective.
Be sure to check back for our second installment, when we’ll discuss how proper ventilation and air sealing affect your home’s energy efficiency.
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