Chimney fans work by employing mechanical venting to overcome fireplace and chimney gravity drafting deficits. When they are turned on, chimney fans, attached atop the chimneys, create a partial vacuum in chimneys . Exhaust gases from the wood or gas fireplace rush into that vacuum and flow up the chimney and out the sides of the vents in the fan.
Difference Between Gravity Venting and Mechanical Venting
Open-fired hearing appliances like fireplaces can be vented by gravity venting or mechanical venting.
Gravity venting is also called natural venting. To create a draft, gravity venting uses the difference in gravity of cold vs. warm air. The disadvantages of gravity venting alone is that it is very sensitive to indoor and outdoor temperatures, barometric pressure, wind, and airflow obstructions within and around the chimney and house.
Mechanical venting uses a fan or blower in-line or at the termination point to create a proper draft. The mechanical venting can overcome any problems of gravity venting and can adapt to changing conditions such as exterior winds or temperatures. An Exhausto – Enervex chimney fan is a powerful type of mechanical venting.
How Chimney Fans Work
A chimney fan is installed on the top of the chimney, over the flue. It is wired to the home’s 110 volt electrical system and managed by use of a variable speed control that is like a dimmer switch. The switch is normally installed close to the fireplace so its operator and see the results of the adjustments he or she makes. When the fan is turned on, it lowers the air pressure in the chimney, creating a partial vacuum. The exhaust gases rush into the vacuum and flow out of the vents in the sides of the fan.
The homeowner can regulate the ‘pull’ of the fan by adjusting the variable speed control switch. This clever feature allows one to make the flames burn higher or lower, at will, by regulating the speed of the fan.
The chimney fan, by the way, also serves as a chimney cap, keeping rain and snow out of the chimney. The screen sides prevent critters such as birds, squirrels, and raccoons from entering your home via the chimney and fireplace.
Due to the wiring required, we recommend chimney fans be installed by a licensed electrician.
What Fireplaces Are Compatible with Chimney Fans
Now that you know how chimney fans work, is your particular fireplace and chimney compatible with the use of a chimney fan?
Chimney fans will work on the following types of fireplaces and chimneys:
- Wood-fired fireplaces with single or multiple flue;
- Gas-fired fireplaces with single or multiple flues or with dampers;
- Wood stoves and fireplace inserts;
- Single or multiple-sided fireplaces;
- Outdoor fireplaces; and
- Pizza ovens.
Enervex Chimney Fans are Guaranteed to Work!
Enervex Chimney Fans come with a six-month money-back guarantee. If one does not solve your chimney draft problem, you can return it within six months and receive a complete refund. In addition, the Enervex Chimney Fans have a ten-year warranty against corrosion and a two-year warranty against defects in workmanship and materials.