Understanding The "Stack Effect"
How Air Movement Within Your Home Affects The Building
The diagram above shows how air moves in a home. As air is heated in a home, it rises upwards, exiting through the attic and upper levels.
As air seeps out of the upper levels, a vacuum is formed below, which is filled with outside air, as well as air from your crawl space or basement.
No matter how still it may seem in your house, air is always on the move. To some extent, this is a good thing -- it helps to freshen your house, and it keeps you supplied with new air to breathe.
Due to convection, the warmest air in your home will rise upwards to the attic and upper levels. From there, the air escapes through several dozen cracks and openings present there.
As the interior air exits the crawl space through the top, exterior air is pulled into your home at the bottom, and the cycle continues.
How Do Air Leaks Occur?
Your house is built out of thousands of small pieces, including nails, screws, pipes, and much more. Over time, these components will shrink, bend, and expand, causing small gaps to form where they meet.
These gaps are also created as part of the construction process. Plumbers, electricians, HVAC contractors, and others will drill a series of gaps to make room for wires, pipes, and air ducts.
Unless these are sealed after they're cut, they will let air pass through from then on.
At Basement Systems, our experts have repaired hundreds of thousands of basements and crawl spaces! Our systems have been carefully designed with common sense and building science in mind.
To meet with your local dealer for a professional crawl space repair estimate, contact us by phone or e-mail today! Our estimate includes an on-site expert inspection and measurement, detailed answers to any of your crawl space questions, and a customized cost estimate.
Crawl space air can enter a home through many openings -- including around the interior entryway door, shown above.
As much as 40% of the air in your living are has come from the crawl space. If there's mold in that space, it could be affecting your health.
More about Mold & Your Health
The Stack Effect & Crawl Spaces
The easiest way for outside air to enter into your crawl space is by flowing in through your crawl space vents. If your doors are drafty and not airtight, air can easily pass into your home through this avenue as well.
During the summer, air vented into the crawl space will cool quickly, causing humidity in the space to condensate. This will lead to rot and mold growth.
Condensation that forms from the condensation will ruin fiberglass insulation and lead to potentially serious structural issues.
As this air is pulled upwards, anything in the air is brought with it. This includes mold spores, dust mite waste, animal dander, radon, and other substances that can lead to health issues.
During the winter, cold air will be brought into the space. This will cool all utilities in the space -- including the furnace, water heater, air ducts, and HVAC system.
As this cold air is pulled upwards, it will cool the floorboards above and create a drafty, uncomfortable environment in the home.
Have you ever noticed that, after a snowfall, some roofs are covered in snow while others are bare?
Bare roofs after a snowfall are a sign of a poorly insulated attic. As heat escapes, the snow melts away.
More about Attic Insulation
The Stack Effect & Attics
We know that heated air rises in the home, ending up in the attic. It's not uncommon for an attic to reach temperatures of 120°F or higher in the summer!
In the winter, the attic is a major source of energy loss for a homeowner, as all the air they've paid to condition flows up and out of the house.
This air flow makes for a drafty home, even when the crawl space is sealed. The lower levels will seem cold, drafty, and uncomfortable.
In the summer, a superheated attic will warm the upper level of the home as well. This can make sleeping uncomfortable, and will add to your monthly cooling bills.
There's a common misconception that adding more insulation will address air leaking. However, fiberglass insulation will filter the air -- not stop its movement.
Along with insulating your attic, we recommend that you air seal your attic, using spray foam to seal any significant gaps. You may also be interested in systems that both seal and insulate your attic (while also allowing for ventilation) such as SuperAttic™.
Seal Your Crawl Space For A Healthier Home Environment!
Sealing your crawl space controls mold and rot in your crawl space, reducing allergens in the home and creating a healthier, better preserved home. As an added benefit, you'll also save a bundle on your utility bills!
It costs you nothing to meet with our experts for a free, no-obligation crawl space repair estimate! We'll stop by your house to answer any questions you have, measure your crawl space, and provide a professional inspection. Before our visit, we'll also mail along a complimentary copy of our full-color crawl space book -- which is filled with information crawl space repair and the services we offer.
Our dealers proudly serve throughout Canada and the United States. There's a locally owned and operated dealership in your area that's standing by to serve you!
Looking for a price? Get a no cost, no obligation free estimate.