b-vent question

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Jul 20, 2013
27
upstate ny
I know it's pretty bad, but what is the % efficiency of propane b-vent heaters such as the ones Empire makes? I have a small 3-season porch we'd like to use in the winter , but the numerous windows won't allow for a thru the wall type heater, and it's too small for even a small woodstove. thanks.......
 
Most gas appliances will be in the 70 - 80% efficiency.
B-Vents are sometimes problematic, because of the Natural Draft...
I'd go for a Direct Vent, myself.
Completely sealed combustion.
 
I agree with Daksy. Many of ventless gas fireplaces are b-vents which is going to exhaust the combustion and water vapour in the house. Whether it is a clean combustion for propane, that is still debatable. Without risking it, Direct vent is probably the best solution
 
Definitely look towards a DV. If you can vent a B vent through the roof, then you should have no trouble vertically venting a DV appliance.
 
I agree with Daksy. Many of ventless gas fireplaces are b-vents which is going to exhaust the combustion and water vapour in the house. Whether it is a clean combustion for propane, that is still debatable. Without risking it, Direct vent is probably the best solution

the b vent stoves vent thru the roof, not into the room. direct vent units vent thru the wall, but code says you can't vent them under a window, and my porch is all windows. thru the roof would work, but they are quite inefficient because they use room air and much of the heat goes up the chimney. my original question was, what per cent efficiency are they, if anyone knows.
 
the b vent stoves vent thru the roof, not into the room. direct vent units vent thru the wall, but code says you can't vent them under a window, and my porch is all windows. thru the roof would work, but they are quite inefficient because they use room air and much of the heat goes up the chimney. my original question was, what per cent efficiency are they, if anyone knows.

I answered your question in the comments above.
For the record, DV stoves can vent EITHER horizontally or vertically.
There ARE some models may be vented ONLY horizontally, but not ALL are.
 
Here's a page from a Jotul b-Vent brochure:

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