Can high efficiency furnace be vented through the roof?

That depends on whether you have a standard efficiency or a high efficiency furnace. If your furnace has an AFUE rating below 90 percent, it will most likely have a flue pipe that goes up through your roof.

How to Vent a Furnace in a Roof

  1. Locate the spot to install the vent pipe, using a tape measure to determine distance from a wall or other identifiable spot.
  2. Run the vent pipe up through the roof and install a metal or PVC flashing collar over it.
  3. Put a cover on the vent.

One may also ask, how long can a furnace vent pipe be? Vent Pipe Size and Length Two 45° elbows are equivalent to one 90° elbow. The minimum length certified for use with this furnace is 5 ft and one elbow, not including the vent and air intake terminals.

Also, does a high efficiency furnace need a fresh air intake?

Since high efficiency furnaces draw air directly from outside, the furnace itself does not require a fresh air intake in order to replace inside air that otherwise would have been drawn from the room the furnace is located in. The open flue on conventional furnaces better allow for the escape of moisture.

Do all furnaces have vents?

Type B vents are a standard design that most modern gas furnaces use. Gases produced during combustion are very hot and as such, easily rise through the flue. The air is then vented outside through a B-vent pipe which is set vertically to expel combustion air through the roof.

What are the two pipes coming out of my furnace?

Direct-vent (two-pipe) system: The two-pipe system is most common in home heating applications. It provides a direct intake vent that brings outside air to the sealed combustion chamber with one pipe, while a second vent pipe provides sealed venting of exhaust gases back to the outside of your house.

Why do high efficiency furnaces produce water?

High-efficiency furnaces create water because they have two heat exchangers, one more than a conventional furnace. The two heat exchangers absorb so much heat that the exhaust gas changes from a gas state to a liquid state. Condensation forms and then drains out through the condensate line.

How far can you vent a furnace?

Highlights of Gas Heater Vent Clearance Distances The exhaust vent terminal shall be located at least 3-feet above any forced air inlet located within 10-feet. The vent terminal shall be at least 12-inches below, 12-inches horizontally from, or 12-inches above, any door, window, or gravity air inlet into a building.

Are high efficiency furnaces safe?

In other words, it’s a safety hazard. High efficiency furnaces with sealed combustion don’t have this problem and are a good choice for furnaces that will operate from a sealed attic or crawlspace.

What comes out of furnace exhaust?

The furnace exhaust flue, also called a furnace exhaust stack, is a metal tube that vents the noxious combustion gases from the heat exchanger to the outside. Inside the stack resides a damper that regulates the pressure between the air from the furnace and the outside air.

How do high efficiency furnaces work?

Types of Gas Furnaces Condensing Gas Furnace: A high-efficiency furnace (90% AFUE or higher) utilizes a second heat exchanger to heat the air from condensed exhaust gases in order to reach higher efficiencies. A high-efficiency condensing furnace requires specialized venting.

Where is the air intake on a furnace?

An updraft furnace takes in cool air at the bottom of the unit and, once it is heated, blows it into ductwork above the furnace. This type of furnace is commonly located in basements, and the air intake is at the bottom of the unit.

How far should vent pipe stick out of roof?

Open vent pipes that extend through a roof shall be terminated at least 6 inches (152 mm) above the roof or 6 inches (152 mm) above the anticipated snow accumulation, whichever is greater, except that where a roof is to be used for any purpose other than weather protection, the vent extension shall be run at least 7

How do you seal flashing roof vents?

Run a bead of silicone caulk around the interior (bottom side) of the neoprene rubber gasket opening of the flashing. Slide the vent pipe flashing over the vent pipe. Lift up the loosened shingles and rotate the vent pipe flashing down onto the roof and under the shingles.