Can lighting a fire in the fireplace with a chimney make the rest of the house colder?

Answer 1

It can, though this may be counter-intuitive.

The heated air rising out of the chimney must be replaced by air from outside. Usually this air enters the house through open or leaky windows and doors, through openings in the walls, or through under-eave vents into the attic. Depending upon the placement of the air sources and the temperature of the outside air, this may have significant cooling effect on the living space of the house.

To counteract this effect, most well designed residential furnace systems are provided with a "makeup air" duct from outside directly into the furnace room. This way, the cold air from outside needed to replace the air leaving through the chimney can enter directly into the furnace burner or draft diverter. Some modern fireplace designs take a similar approach with a small makeup air duct or vent located near the fireplace.

Answer 2

It can, those this result may be counterintuitive. The heated air rising out of the house through the fireplace's chimney must be replaced with air from outside. This may be through open windows and doors, through door jambs, through leaks in the walls or through under-eve vents. Depending on the placement of these ventilation sources and the temperature of the outside air, the cooling effect can be significant. This is why most well designed furnace systems provide a "make up air" duct from outside directly into the furnace room. That way the cold air is drawn directly into the burner or draft diverter, rather than being pulled through the living area of the house.

Answer 3

Yes, lighting a fire in the fireplace can make the rest of the house colder if the chimney is not drafting properly. Inadequate drafting can cause smoke and cold air to enter the room instead of drawing warm air out of the house through the chimney. It's important to ensure proper ventilation and maintenance of the chimney to prevent this from happening.