Roof turbines are designed to provide ventilation to a home's attic. Though covering the turbine in winter may seem like a good idea to conserve heat and save on energy costs, the reduction in air flow may cause other problems.
Roof turbines not only work to remove hot air from summer attics, they also provide ventilation to reduce moisture. By covering the turbine in winter, this effect is lost and moisture can quickly build up in the attic, causing structural damage and increasing the chances of mold and mildew.
Less Efficient Insulation
Covering a roof turbine in winter may actually increase energy costs. This is due to the increase of moisture in the attic, which will dampen the exposed insulation. As the insulation becomes damp it becomes less efficient and allows more heat loss from the living space of the home.
To reduce heat lost through the attic of a home, home owners should make sure the home's ceiling is properly insulated. Adding insulation or replacing the existing insulation with something more efficient is relatively simple and inexpensive.