How to Heat a House Evenly With a Gas Furnace

Gas-Powered Heating Systems

• Gas-powered furnaces operate within a forced-air system that delivers warm air to different areas in a home. Room vents deliver warm air while one or more return ducts sends cool house air back to the furnace unit. In effect, a home’s vent and duct system works as a two-part air delivery system. The furnace system’s overall purpose works to condition and re-condition a home’s air environment by removing existing cold air and replacing it with warm air.

Closed-Air System

• A closed-air system uses a home’s existing air as a medium for carrying heat throughout the home. Most homes have one centrally-located return duct that draws cold air out of the living space. In order to heat a home evenly, the air in a home must have access to the return duct opening. This means, any rooms closed off from the vents cause an air imbalance within the heating system. “Missing” air causes air flow imbalances within the furnace’s circulation system. These imbalances can cause a furnace to operate at less-than-optimal efficiency.

Insulation and Sealing

• A poorly insulated home allows heated air flows to seep through a home’s wall and ceiling structures. Gaps and crevices around windows and doors also allow outside air to seep indoors. Under these conditions, a gas furnace system has to work harder to condition, or warm the extra air entering the home. In effect, the intended closed-air system has become an open-air system. As a result, some areas in the home may heat unevenly because of extra air entering at specific points. Properly insulated walls and ceilings help contain heated air inside a home. Sealing up gaps around windows and doors further contributes to an evenly heated living environment.

Return Air Flow

• As return air ducts deliver cold air back to the furnace unit for heating, keeping a return duct free of any blockages or obstructions can help to produce even heating throughout the home environment. This means removing any furniture, overhangs or draperies impeding air flows to the return duct. Return-duct air flows can also be blocked or slowed by dirt or debris caught inside the duct or accumulated on the outside vent. Clearing existing debris from duct passages and vent fins can help produce needed air-circulation levels within the home.