The Comfortable Home: Air Sealing

Part One of Two-Part Series

Controlling the airflow in and out of your home is a cost-effective way of creating a healthy home environment, reducing energy costs, and increasing the durability of your custom home anywhere in Colorado.

Uncontrolled air movement (air leakage) in the home is caused by holes and pressure. You may have great insulation but it’s ineffective if air movement is uncontrolled in your home. Air sealing trumps R-Value.

The areas where holes can be found in a home are many: At the rim joist, sill plate/foundation joint, gaps in the sheathing, between floors, at the windows and doors, through home penetrations such as hose bibs, sprinkler lines, HVAC vents, plumbing pipes and vents, electrical wires and outlets, soffits, attic hatches, recessed lighting cans, and fireplaces. Forgive me if I have missed any!

There is also the stack effect within the home. Less dense warm air rises while more dense cold air sinks creating airflow and pressure. Think fireplace and hot combustion air. Pressure can be caused by atmospheric conditions including wind.

In the Denver, Colorado area, we can get a lot of wind and wind pressure can exert enormous pressure on a home. Because air pressure inside of a home is less than the pressure outside the home equalization wants to occur. Whether you’re taking advantage of our Owner-Builder program or our Turnkey approach to building your custom home, recognizing the issues related to air sealing will prove helpful.

These leaks are environmentally detrimental by consuming more natural resources when the thermostat is calling for more heating or cooling to make up for what is being lost. Health wise they are detrimental due to pollution and allergens entering the home.

Financially they are a drain on your checkbook because the heating or cooling that you’re paying for, which is more than 50% of your energy bill, is escaping outside the home. And stress? Let’s face it: Cold drafts are uncomfortable and annoying.

Air leaks can also be damaging to the structure of your home. Warm air escaping into the attic is a major cause of ice dams on the roof. Warm air leaking thru poorly finished drywall, recessed can lights or electrical fixtures including smoke detectors can warm a roof and melt snow temporarily allowing ice to form later.

How Vapor Moves

Air sealing also helps control the movement of vapor moisture that can cause mold in all areas of the home due to higher humidity (higher pressure) outside the home.

• Vapor always moves from more to less and from hot to cold
• Vapor moves by diffusion and by air transport
• Vapor movement by air transport is much greater than by vapor transport by diffusion

Air sealing helps maintain dry basements and attics eliminating conditions conductive to mold. Additionally, the service life of your furnace and air conditioning systems will be extended because they are not being cycled on an off as frequently. Air sealing will give you a more comfortable, healthier and energy efficient home.

Whether you’re in Colorado Springs, Golden, Boulder, Englewood, or anywhere in the Denver area, understanding how air sealing protects your investment is important.

We’ll cover the How to and Verification of Air Sealing in our next blog post – part two.