Although hedges have been utilized for many years, their value has increased with the advent of higher fuel costs. Winter winds in North Carolina usually blow from the northwest and accelerate the rate of air exchange between a house and the outdoor environment. Savings of up to 23 percent have been recorded in comparing completely exposed homes and a house landscaped to minimize air infiltration. Summer winds normally blow from the south or southwest with generally positive effects on human comfort. Tall trees on the south and west can reduce temperature while allowing breeze to pass beneath and through the foliage canopy.
Windbreaks obstruct and redirect the flow of wind.
As wind strikes an obstruction, it can move over, around or through it. The extent of protection on the leeward side is related to the height and length of the windbreak. Impenetrable windbreaks create a strong vacuum on the protected or leeward side, which reduces the protection. Windbreaks composed of living plants allow some of the wind to penetrate, which makes them more effective. Most homeowners need to consider the size requirements of the living hedge.