Concentric vent kits too expensive

[Jaja]

I bought a new Beacon Morris garage heater and want to set it up as separated combustion which requires a concentric vent kit like this:

For what these things are, they are too expensive. $200-300!! Heater was only $350 new. I know I'm preaching to the choir here.

Has anyone pieced together what's needed any cheaper?

 

[Firebrick43]

Just run a seperate vent and intake laid out by your heaters manual. It's much cheaper.

 

[danski0224]

That's the price of lawyers and liability.

 

[CKS1955]

I bought and installed one, but you could easily replicate this.

Jay

 

[Jaja]

It's that darn air box that's so expensive. I had one on a previous sealed combustion unit, but I'm a little older and wiser now.

My garage is attached and since it's near the street I want to avoid big ugly exhaust vents anyway. I don't see any mention of a limitation in the manual on the intake piping length. I'll have to research building codes. Maybe I can run a separate intake using PVC to somewhere less noticeable and exhaust vertically using 4" metal pipe as spec'd. That way I have a smaller exhaust vent and I'm not spending 150 bucks on a tin box.

 

[rlitman]

...Maybe I can run a separate intake using PVC to somewhere less noticeable and exhaust vertically using 4" metal pipe as spec'd. That way I have a smaller exhaust vent and I'm not spending 150 bucks on a tin box.

I wouldn't get them too far apart. If there is a difference in pressure between the two, you may have issues.

 

[Jim greengo]

Do you have a part number for the kit?

 

[Jaja]

Jim,

If you are asking about the Beacon Morris kit, its:

Combustion Air Inlet Kit Number AS-X7-4

for the 30K-75K BTU heaters.

 

[u3b3rg33k]

I wouldn't get them too far apart. If there is a difference in pressure between the two, you may have issues.

doesn't seem to be a problem on hundreds of thousands of 2-pipe condensing furnaces out there.

or natural draft systems for that matter. FUD, unless you're running them to opposite sides of the building. which would be dumb.

 

[finn]

doesn't seem to be a problem on hundreds of thousands of 2-pipe condensing furnaces out there.

or natural draft systems for that matter. FUD, unless you're running them to opposite sides of the building. which would be dumb.

Sounds like exactly what he’s considering, exhaust to the roof and inlet “somewhere else”.

That may cause a pressure differential issue,at least in some wind conditions.

What’s driving the desire for sealed combustion?

 

[Jackfre]

Getting the intake and exhaust in different locations can definitely be a problem. It is largly based upon the type of gas valve, inducer and its ability to handle such differences. A negative pressure gas valve can generally handle it easily, but if you are going to do it make sure you know what you have, and that question will be answered by the manuf installation instructions.

 

[Jaja]

I was thinking of different length runs, so thanks for the advice. I'm still leaning towards separate piping for intake and the exhaust. It's just so frustrating that a tin box is so expensive. I do realize it will improve the efficiency of the furnace though.

 

[u3b3rg33k]

it wont really improve the efficiency of the heater itself - those gains mostly come from not exhausting already heated air up the chimney.

 

[Jaja]

u3b3rg33k, there must be some efficiency gains from warming the fresh outside air prior to it passing through the heat exchanger (when an air box is used)?

 

[CKS1955]

u3b3rg33k, there must be some efficiency gains from warming the fresh outside air prior to it passing through the heat exchanger (when an air box is used)?

It does preheat the fresh air so there is gain there as well as not exhausting conditioned air.

Jay

 

[finn]

The improvement is in reducing air infiltration from outside to replace combustion air, as implied above.

 

[u3b3rg33k]

u3b3rg33k, there must be some efficiency gains from warming the fresh outside air prior to it passing through the heat exchanger (when an air box is used)?

Yes but not much. if it starts condensing (which is where the meaningful gains are made), bad things happen.

It does preheat the fresh air so there is gain there as well as not exhausting conditioned air.

Jay

The main benefit of concentric venting is only having to make one hole in your building.

 

[TTA89]

How more is the concentric vent kit after you buy the parts to make you're own venting kit?

 

[Jaja]

How more is the concentric vent kit after you buy the parts to make you're own venting kit?

I'd like to know...If I could find a source for the air box only that was reasonable. That's my issue here, that box is way overpriced and some places are charging up to $400 for the kit.

 

[TTA89]

My time is worth more than the few hundred bucks you might save trying to piece it together.... I bought the kit and moved on to real projects.

 

[Jackfre]

How big a unit did you buy? How big is the shop?

 

[Jaja]

How big a unit did you buy? How big is the shop?

Been offline for a few days...

I bought a 45K BTU for a 4 bay attached. I'll be dividing it eventually so it'll only be heating 2 bays. 2 double doors insulated and finished interior. Still need buy a vent kit.