Should a Vent Hood Duct Be Insulated?

Oven Vent Hoods

• Using a vent hood over your cooking range not only helps remove odors and nuisance smoke from your kitchen, it also helps keep your family safe by removing carbon monoxide, natural gas odors and other potentially harmful substances from the air around your cooktop. Some range vent hoods use filters to remove harmful particulates and circulate the air back into the kitchen. More common, however, are vent hoods that ventilate air directly out of the home via a system of duct work.

Insulating

• Like other duct systems in the home, insulating the ducts connected to your vent hood reduces nuisance noise and vibration when the fan inside the vent hood is running. But more importantly, insulating duct work wherever ducts run through unheated parts of the home will help prevent air loss through the thin metal ducts and will help prevent the buildup of condensation and the moisture problems that can result from condensation accumulation.

Insulation Materials

• For duct work insulation, the U.S. Department of Energy recommends rigid fiber board insulation for insulating your duct work. Install the insulation according to the manufacturer's directions. Before insulating, however, seal all openings in your duct work; insulating duct work with unsealed openings is an exercise in futility at best. Use mastic sealant or metal tape. Don't use duct tape because it will not provide a good seal and degrades quickly.

Other Considerations

• Just as is the case with insulation in other parts of your home, you should regularly inspect and maintain the insulation on your duct work. Should the insulation around your vent hood duct work become water-logged due to a roof leak or similar problem, the insulation's effectiveness will be compromised and can actually invite moisture problems inside the ducts. Inspect the insulation around your ducts at least once a year and replace any that has become compromised.