Forget AC! Cool Your Home Naturally

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

If you have a tall house — one with multiple levels, high ceilings or both — you may already have the necessary components for taking advantage of the chimney effect. You can use an existing stairwell, atrium, clerestory or other vertical air passage to increase airflow in your house. If you already have the necessary openings at the top and bottom of this airspace, your only task may be to open and close them as needed. Or perhaps you have the needed airspace, and the addition of vents will allow it to function as a thermal chimney.

However, if your house doesn’t have any such features, you can add a chimney or atrium to pull out hot air in summer. You can further enhance the airflow by adding south-facing glass at the top of the chimney to increase the temperature difference from top to bottom, or even by adding a fan to increase airflow when necessary. Placing the outlet on the leeward side of the building will further enhance airflow; as wind blows around the chimney, it will essentially suck air up the chimney. The rate of airflow will be greatest when the cross-sectional area of the chimney remains the same from inlet to outlet.

Wind catchers. If there are breezes in your area — but buildings, vegetation or landforms keep them from getting to your house — there’s another way to bring those breezes indoors. Wind catchers (also known as wind scoops) have been used for centuries in the Middle East, where temperatures are high and buildings are often packed close together. A wind catcher is a tower that rises from the house into the airspace above the rooflines (see illustration below). Its opening faces into the prevailing wind, scooping the breeze down into the rooms below. Capturing air higher up has additional benefits: The air is cooler, the breeze moves faster, and the air carries less dust. When the air is still, well-designed wind catchers can work in reverse, with the chimney effect drawing warm air upward and out of the house.

A wind catcher also can be an elegant solution where windows aren’t oriented well for capturing breezes. The windows may face any which way, but the wind catcher can be precisely oriented to the prevailing breeze. Based on knowledge of wind patterns in your area, you can design a wind catcher with openings in as many directions as you need. For best results, inlets should be at least 8 feet above surrounding obstructions, so take care to integrate this feature with your overall design. If your climate is not hot all year, you may want to add insulated doors to your wind catcher to avoid winter heat loss.

Vegetation and other landscaping. You can use garden plantings and landscape walls to direct, and even cool, a breeze before it enters your home. Rows of leafy trees or tall, dense shrubs can funnel air to open windows, their shade and transpiration cooling the air as it moves through.

RSS | Comments | E-mail | Print