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Vent termination for 90%

jar546

CBO
Joined
Oct 16, 2009
Messages
12,980
Location
Not where I really want to be
Ducane 90% with combustion air taken from inside (lazy, lazy, lazy).

Does the manufacturer allow this installation?

IMG_9533.jpg
 
Here's the technical stuff on the Ducane 90% Gas Furnace Model.

http://www.ducanehvac.com/gas_9092.php

jar546,

I will assume that this 2" pvc pipe is the vent pipe for the appliance, and that

the heating appliance is installed in some type of "below grade" application

[ i.e. - possibly a basement ]. To answer your question, for the vent, the

manufacturer states:

"3. For proper and safe operation, the furnace needs air for combustion and ventilation.

Do not block or obstruct air openings on the furnace, air openings to the area in

which the furnace is installed, and the spacings around the furnace."

and

"7-B. Vent connector is in place, slopes upward, and is physically sound without holes

or excessive corrosion."

Is all of the combustion air, for this appliance, taken from indoors?

The manufacturer' installation instructions do not go in to a lot of detail. While the vent piping in

your pic. seems to comply with installation instructions, it's probably not the best location. Too

much potential for having / getting the pipe "stopped up" with something.

.
 
Last edited by a moderator:
The major issue I see, is the location of the vent immediately below an operable window, the gas regulator should have the vent piped away from the window as well.
 
If its single piped, the vent needs to be 4' below or to the side of the window per IMC, 1' if two piped. It doesn't look like this passes in either case.
 
Near a corner is also a bad place, especially if the intake isn't close to the vent. When it gets breezy eddy currents can cause backdrafts that trip safeties and shut the furnace off.
 
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