Ventilating your home helps cut air conditioning bills.
Too much humidity in a home can cause dangerous moisture buildup that leads to wood rot, paint peeling, and leaks. It is particularly important to ventilate new homes, which are often built to be airtight and heavily insulated to conserve energy. No one wants a house full of cracks and drafts, but sealing off the outside air too efficiently can cause its own problems. Cut your air conditioning bill down and give your house a breath of fresh air by following these instructions.
Ridge Vents
Ridge vents are installed from end to end on the roof and have a low profile, making them less noticeable from the street. They are the most effective non-powered ventilators available, providing uniform cooling along the entire roof deck.
There are two types of ridge vents: filter vents and shingle-over metal and plastic shingle-over vents. The external wind baffle on the ridge vent causes wind to blow over the vent, creating an area of negative air pressure low air pressure. That draws air up from the attic, effectively removing heat and humidity. Look for airvents, ridge vents with filters that protect your roof against rain, snow, dust and insects.
Power Vents
Power vents forcibly exhaust heat and humidity from the attic, even on days with no wind. The air enters through intake vents (typically located under the eaves) and is pulled through and exhausted from the attic with electric fans.
Power attic vents with two-speed controls are appropriate for areas with high temperature extremes. They come with an adjustable thermostat; low speed for energy efficiency ventilation, and high speed which kicks in when the temperature reaches the extreme.
If moisture is a problem in your attic, consider adding a ventilator with an automatic humidistat. These are available in both gable-mounted and roof-mounted styles.
For safety, the motor should have an overload protection to shut the fan off if the motor overheats.
Wind Turbines
Wind turbines use the natural force of the wind to create air flow and provide ventilation. The free spinning turbine is self-lubricating, drawing hot humid air from the attic.
Turbines come in two sizes: 12" and 14". The latter provides almost 30 percent more air flow. Consequently you may need fewer 14" turbines to ventilate your attic.
Whole-House Fans
Whole-house fans exchange air in your home much more rapidly than air conditioning units, providing a fast and efficient way to lower indoor temperatures. Through open windows, cooler outdoor air is drawn indoors, especially at night and early morning hours. And even in the daytime, the air gently stirring throughout your home makes higher temperatures feel cooler.
There are two basic whole-house fan designs: direct-drive and belt-drive. With either one, you can get a variety of speed controls, including single, triple and variable. Direct-drive fans are easier to install than belt-drive because they do not require attic floor joists to be cut. Belt-driven types may take a little more work to install, because you might have to cut a joist, but they offer increased circulation and quieter operation.
For small to medium-size houses, a direct-drive fan is the choice. The blades are mounted directly under the motor and attached to the motor shaft. Install a belt-drive fan in larger homes. A belt connects a pulley on the motor to a pulley on the fan blades. The result is a higher air flow and a quieter fan due to the steeply pitched slow-turning blades that are used.
Foundation Vents
Excess moisture in crawlspaces promotes rot, mold, mildew, and invites termites to dine on the floor joists. Foundation vents are your homes first line of defense against excess moisture.
In homes with crawl spaces and dirt floors, most moisture enters the home through the crawl space. Good crawlspace ventilation circulates fresh air through the crawlspace and exhausts musty, moist air.
Check your foundation vents regularly to ensure they open and close properly. If you have a vent that doesn't work properly just follow these installation instructions to replace it.
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