For a direct vent gas-fired furnace, where is combustion air drawn from?

For a direct vent gas-fired furnace, combustion air is drawn from outside. This design is crucial because it minimizes the risk of backdrafting, where exhaust gases flow back into the home. By sourcing air directly from the outside, the system can maintain proper combustion efficiency and safety.

In addition, using outside air prevents the furnace from depleting the indoor air supply, which could lead to negative pressure in the home and potential hazards. The direct vent system uses a sealed combustion process, where both air for combustion and exhaust gases are vented through a dual pipe system. This enhances safety and energy efficiency, making it an ideal choice for modern HVAC installations.