Gas Stove Direct Vent Question

[E30]

Possibly dumb question. Just picked up a 2003 Enviro Westport free-standing gas stove. It is designed as direct vent (4”/6” coaxial pipe). I want to test this thing out for a season and not have to modify my existing, roughed-in class A wood stove chimney. Can I just run some 4” single wall from the stove to the chimney ceiling flange and install a 4 to 6” adapter up there? Then just let the stove breathe interior air from the top of the stove fitting?

 

[Lennox65]

No. Direct vent venting needs to be sealed and continuous from the appliance to the exterior, using only tested and listed components for the respective appliance.

 

[E30]

As long as the exhaust is sealed, why does the intake need to be sealed? Why cant it just draw air from the house like a woodstove. I'm an Engineer so i need some physics reference to be satisfied

 

[chrisarrington]

As long as the exhaust is sealed, why does the intake need to be sealed? Why cant it just draw air from the house like a woodstove. I'm an Engineer so i need some physics reference to be satisfied

Because that is the way it was designed, tested and UL listed. B vent fireplaces work like you are describing but they have a completely different design and normally pull air from underneath the fireplace. I think I can speak for most of the professionals here, in that, we aren't going to tell you it is okay to deviate from manufacturers standards regardless of where it would work or not.

 

[Lennox65]

As long as the exhaust is sealed, why does the intake need to be sealed? Why cant it just draw air from the house like a woodstove. I'm an Engineer so i need some physics reference to be satisfied

Of course you can do anything that you want to do. I am merely quoting (although loosely and generally) the requirements for safe operation of a direct vent appliance. It would probably work in the way that you described, but it could interfere with any ERV, HRV, or other ventilation system.

Dura Vent makes an adapter that utilizes an existing Class A Chimney.

 

[E30]

Ok, thats fair. Let me ask you this. Does this adapter allow me to do what i want to do? There a'int a whole lot of info on it. Thanks

Enviro Westport B Vent Adapter (50-841) (50-4176)

This is the official Enviro Westport (and Ascott) B Vent Adapter (also called Natural Vent Adapter). This starter piece is used when these gas or propane

friendlyfires.ca

 

[Lennox65]

Ok, thats fair. Let me ask you this. Does this adapter allow me to do what i want to do? There a'int a whole lot of info on it. Thanks

Enviro Westport B Vent Adapter (50-841) (50-4176)

This is the official Enviro Westport (and Ascott) B Vent Adapter (also called Natural Vent Adapter). This starter piece is used when these gas or propane

friendlyfires.ca

I don't know anything about your specific stove or the venting options. Do you have the install manual?

 

[E30]

I do. It does not mention this. Basically just shows an option of the coax pipe going up a class A chimney with a funky chimney cap that allows the intake and exhaust to work properly .

 

[Lennox65]

https://enviro.com/custom_content/docs/manuals/C-14530%20Instruction%20Westport%20Steel%20Owners%20Manual.pdf

Page 32 shows a B Vent option. This is probably a newer model than yours so I don't know if this is applicable.

 

[E30]

That is what i was looking for. Yes, that is a newer model. What is the spillage switch looking for? Thanks

 

[Lennox65]

That is what i was looking for. Yes, that is a newer model. What is the spillage switch looking for? Thanks

What is a spillage switch?


A spill switch is a device designed to sense and correct unsafe venting of combustion gases from a gas-fired appliance into a building.

If the exhaust backs up and "spills" out, it will cut the voltage to the gas valve.

 

[E30]

Ahh, ok thanks for all of your wisdom!

 

[E30]

So i guess the idea is that with a coaxial pipe, any exhaust leakage will just get pulled back into the stove thru the intake stream and not go into the room.

 

[Lennox65]

So i guess the idea is that with a coaxial pipe, any exhaust leakage will just get pulled back into the stove thru the intake stream and not go into the room.

Not so much that because drawing the exhaust as combustion air will snuff out the flame. All direct vent units have a sealed glass panel that separates the combustion area from the living space. That is the reason that they don't need spillage switches or hi limit switches.

 

[E30]

Ok, makes sense. Thanks

 

[E30]

So i bought a used like new Enviro Westport stove (2003 model) for $350. If I am to vent it thru my class 1 chimney, I'm looking at about another $1100 of chimney parts with me doing the install myself. The stove reportedly functions, but the previous owner only used it a few times since purchasing it. Is there anything that can go wrong with these that would be super expensive to fix or are they fairly simple, bulletproof technology? Still deciding about this or a woodstove. Thanks

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[Lennox65]

So i bought a used like new Enviro Westport stove (2003 model) for $350. If I am to vent it thru my class 1 chimney, I'm looking at about another $1100 of chimney parts with me doing the install myself. The stove reportedly functions, but the previous owner only used it a few times since purchasing it. Is there anything that can go wrong with these that would be super expensive to fix or are they fairly simple, bulletproof technology? Still deciding about this or a woodstove. ThanksView attachment 309221gy?View attachment 309220

Standing pilot systems are dependable. Pilot assembly and valve parts should stay available for awhile. The burner parts and logs may "age" out though, and become unavailable from the manufacturer at some point. I don't have any experience with that specific model, but I have done service on similar gas stoves of that vintage and they have held up well.

 

[E30]

Thanks. The stove is still made today but i imagine has an electronic pilot