A Direct Vent gas fireplace is a safe and efficient alternatives to traditional gas and wood burning fireplaces. They don’t require a traditional brick chimney but instead, use a completely sealed firebox and venting system to pull fresh outside air into the firebox for combustion while simultaneously venting combustion gases outside of the house.
The fireplace pulls in air from the outdoors through the outer chamber of a double vent pipe; the inner chamber of this pipe exhausts fumes. The natural flow of heat creates a convention loop and as hot air exits the pipe, cooler, denser air is siphoned in to fill the void. Since direct vent fireplaces generate cooler combustion gases, no flue is needed; the pipes can be installed through the wall.
Because the firebox and venting system are sealed the combustion air is drawn from outside the home and the by products of combustion will be vented outside, preventing build up within the home.
Direct vent fireplaces burn natural gas or propane like traditional fireplaces; however, they convert most of the fuel to usable heat. Unlike a wood fireplace, they are completely sealed off from the interior rooms by a glass door, which prevents significant heat loss from the room
Direct vent gas fireplaces are also known as just a Gas fireplace or Zero Clearance Fireplaces
What is a Zero Clearance Gas Fireplace?
Zero-Clearance Fireplaces are pre-manufactured fireplaces where the unit or firebox can be placed almost directly against combustible materials like wood, walls, or paneling. This eliminates the need for a buffer zone and allows the fireplace to fit into much smaller openings. The fireplace is built using materials that do not allow the outside of the fireplace to get hot enough to burn other materials.
What kind of venting does a Direct Vent Gas fireplace need?
There are two types of direct vented appliances: co-linear or collinear, and co-axial. The term “direct vent” is used interchangeably between the two venting options which sometimes adds to the confusion.
Coaxial direct vent system.
The vent pipe is a pipe within a pipe. A common system includes a 5″ inner exhaust pipe surrounded by an 8″ outer pipe. The space between the two allows for the air intake. This type of vent pipe can be installed inside a wall or wooden chase. There are clearance requirements to combustible materials (e.g. wood studs or drywall). Typically, if the vent is running vertically, you need a minimum of 1″ clearance all the way around the pipe. If the pipe is running horizontally, you need a minimum of 3″ clearance from the top of the pipe and 1″ clearance from the sides and bottom of the pipe. These vent systems can be run up through a roof with a vertical endpoint or out through an exterior wall with a horizontal termination.
Co-Linear direct vent system.
Co-linear systems feature two pipes that run parallel to each other, one to pull in fresh air for combustion, the other to exhaust combustion byproducts. Co-linear venting is most often used with Direct Vent fireplace inserts in masonry chimneys and can only be terminated vertically.
Direct Vent Fireplace Installation
Direct Vent fireplaces can be installed in practically any location but must be installed correctly by a licensed professional. The fireplace should be serviced annually to clear and calibrate the burner