Big maxx vent question

[Mike in Ohio]

My shop has 2 bays separated by a wall. The building is cement block. This winter I am insulating one bay and will install a Big Maxx or similar type heater. There is an 8" hole in the block from a Ben Franklin stove that was there 35 years ago. I plan to run the exhaust vent thru that hole as it is in a convenient place to mount the heater. It is about 2 feet from the wall between bays. Next I plan to insulate and put a heater in the other bay. Can I put a wye in the exhaust for the first heater and run the 2 together thru the wall? If so should I increase the size of the exhaust pipe after the wye? Or is this a bad idea, and I should just bust out 1/2 a block for a second exhaust?

Thanks

 

[spudley]

Can I put a wye in the exhaust for the first heater and run the 2 together thru the wall?
Thanks

B-vent (double wall) manufacturers make wye's so in theory I'd say yes. But there are routing requirements that discourage too many turns.
I'd increase the size after the wye.

 

[Mike in Ohio]

B-vent (double wall) manufacturers make wye's so in theory I'd say yes. But there are routing requirements that discourage too many turns.
I'd increase the size after the wye.

The plan would involve only 1 45* bend in the first line. The second would run straight to the wye, so technically 1 45 there too.

Thanks for the reply.

 

[Showkey]

Power vent ? One device per vent.

No B vent for horizontal vents.

 

[Mike in Ohio]

Power vent ? One device per vent.

No B vent for horizontal vents.

Why not B vent for horizontal?

 

[LS6 Tommy]

Power vent ? One device per vent.

No B vent for horizontal vents.

Why not B vent for horizontal?

B vent connectors can run horizontally as long as they are properly pitched and are shorter than the vertical run to the termination. B vent cannot terminate horizontally.

Tommy

 

[Redraptor]

B vent connectors can run horizontally as long as they are properly pitched and are shorter than the vertical run to the termination. B vent cannot terminate horizontally.

Tommy

I guess I don't understand the physics of B vent as it applies to power venting. I don't see an issue with a short piece of pipe (no elbows) from the unit to outside. What you said makes perfect sense for a draft.

 

[brewchief]

I guess I don't understand the physics of B vent as it applies to power venting. I don't see an issue with a short piece of pipe (no elbows) from the unit to outside. What you said makes perfect sense for a draft.

A horizontal vent is considered under positive pressure, in the past B-vent was allowed under certain circumstances but it was normally limited to one piece of pipe going out the wall and any other pipe had to be single wall and all joints and seams sealed with high temp silicone or other means. A couple code cycles back that changed and the stainless steel gasketed pipe is now required.

A vertical vent is considered under negative pressure due to the draft created so single wall and B-vent can be used.

Some equipment will have different venting instructions based on the application, residential may be different then commercial, if a building is connected to a residence in any way expect for it to be considered residential, some inspectors may consider a detached shop commercial and some will consider it residential if it's on a residential property.

Sent from my SM-G965U using Tapatalk

 

[dfiler2]

Technically most codes say not to terminate b vent horizontally, but they also say to follow manufactures instructions and most companies show their products terminated horizontally. My only concern would be the possibility of one unit running and pushing the exhaust into the other room, with an 8" hole you might be able to get 2 3" b vents through the wall then separate the two terminations by a couple of feet.

 

[fitter30]

Heres a good flue booklet for b vent
https://www.google.com/url?sa=t&sou...FjAJegQIAxAB&usg=AOvVaw2bFnHypf0PfBi47sTpKo8u