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  1. #1
    Join Date
    Apr 2008
    Location
    Upstate New York
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    799

    anyone make a GOOD B vent fireplace

    Still having a hard time liking the DV pipe size coming thru my garage wall. Does anyone make a decent B vent freestanding FP ?

  2. #2
    Join Date
    Apr 2008
    Location
    Upstate New York
    Posts
    799
    And if so can they vent like a dv ? The dv was going to come ou tof the top of the fp like 6" vertical then 90 thru wall thimbal abot 12" horz then 90 or 45 up to chimney then 90 into chimney then it was flev up the chimney.

    If there is one we could do this with with 4" B vent the pipe may not bother me as much being smaller and then I will look for a co that sells and installs that brand.

    Just didnt know if B vent had to run all vertical

  3. #3
    Join Date
    Aug 2004
    Location
    S.E. Pa
    Posts
    6,137

    Thumbs down bad choice

    You'd have to check the venting charts in each specific model fireplace but the larger question would be why take a step backwards and use a B-vented fireplace? They should be banned and have no place in a modern home.

  4. #4
    Join Date
    Apr 2008
    Location
    Upstate New York
    Posts
    799
    Humm pls explain. My home was built in 1953 so modern its not,lol

    The reason for the B vent is the smaller dia pipe and the way they need to go into my garage with it.

    Other than using inside combustion air which alot of appliances do whats your problem with B vent ?

  5. #5
    Join Date
    Apr 2008
    Location
    Upstate New York
    Posts
    799
    hearthman, why do you feel they should be banned ?? Is it because they use inside combustion air ?

    If so explain this to me ; my neighbor has a gas range, dryer, furnace ( not condensing) and water heater, and wood burning fp, all of which I believe use inside air correct ?

    They dont seem o have any problems and are in their 70's and have raised 4 kids in that house !

    Maybe you have other reasons more vaild, pls share. Thank you for your insight..

  6. #6
    Join Date
    Dec 2003
    Location
    Salisbury, MD.
    Posts
    1,473
    check with Rinnai. The problem with b vent appliances is the fresh air requirements can be an issue if not done right.

  7. #7
    Join Date
    Apr 2008
    Location
    Upstate New York
    Posts
    799
    Thanks Freejohn !

    Hearthman; why make a statement with nothing to back it up then never respond ??If you feel they "should be banned" pls let us know why, just making that statement then never coming back to respond tells me you should have never responded in the first place.

    Either back up your statement or keep it to yourself please. I am more than willing to listen to your reason for you statement but haven't heard it... If you are going to share your opinions so freely back them up !

  8. #8
    Join Date
    Aug 2004
    Location
    S.E. Pa
    Posts
    6,137

    Frown responding to this forum

    In case you didn't know, responding on this site is voluntary. I don't have a contractual obligation to answer questions within a specific time frame. It has been two whole days. It's getting cold. I'm in the hearth industry. Hmmm. Maybe, its because I'm getting busy??????

    I posted the way I did because I wanted you to do some homework of your own. You can search this site as well as the rest of the web for a ton of information on this. It doesn't help you understand nearly as much as if I just posted an answer. BTW, the correct answer could fill a book but I'll try to be brief:
    B-vent is atmospheric venting. This means is is wholly reliant upon the conditions of the Combustion Appliance Zone (CAZ) as well as outdoor atmospheric conditions. Now, B-vented appliances have very low depressurization limits, meaning they tend to spill flue gases if you look at them cross-eyed. Regardless of date/ type of construction, all homes are undergoing weatherization, which has a dramatic effect on atmospheric venting. Systems that used to seem to work fine are now failing. Some northern states, such as Minn. have essentially banned B-vent in all new construction because they know it won't work when the house is turned into Tupperware.

    Now, even when you are not using the appliance, meaning its burners are not firing, B-vent is still open to the sky. If your CAZ is depressurized, as many, if not most are, it will draw cold air down the vent into the room. The cold air infiltration will trip the thermostat calling for heat. If the appliance tries to fire, it may not prime and backdraft. At the very least, it may trip the high limit spill switch triggering a service call.

    Bugs and odors can enter the home through B-vent.

    B-vent does not last forever. The inner aluminum lining erodes. I just opened one this afternoon on an 80% furnace. The inner liner was full of aluminum oxide powder and the liner had many paper thin sections. Once built into the home, nobody wants to pay to replace B-vent.

    Of all the homes I inspect, I'd say less than 5% have B-vent proper installed including firestopping and support.

    When firing, your typical B-vent appliance can exfiltrate ~150 CFM.

    The draft hood or relief opening for B-vent has the nasty habit of working. This relief is there so if you get a down draft, it burps out into the room so the pilot light is not extinguished. They designed it this way over 100 yrs ago when homes leaked like a sieve. Now, when it spills into the home, it stays in the home. According to ANSI Stds. a draft hood is allowed to spill for up to 10 minutes. They have to dummy the spill switches so they don't trigger a false trip during this interval. BTW, the spillage from these hoods often misses the spill switch altogether.

    There is no requirement under UL 411 to secure the vent sections with screws. I see B-vent separated all the time. You cannot screw into the insulated sections and only over the overlapping joints with short screws that do not penetrate the inner liner.

    B-vented appliances are severely with regards to rooms the appliance can be located in and makeup air. They should not be in bedrooms. In garages, they must be at least 18" off the floor. Direct vents do not suffer these restrictions.

    B-vented appliances are mid to lower efficiency. In hearth appliances, they are generally tested to ANSI Z21.50 which is for decorative--not heating appliances. You don't buy a B-vented fireplace for heat.

    Most B-vented fireplaces I've seen have bimetallic dampers. Very few of these dampers have ever either provided an effective seal when closed or opened fullly within 45 seconds of firing without snagging or hanging up.

    Some B-vents have very short warranties.

    These are a few of the drawbacks to B-vent.

    There cvcman, I hope that meets your requirements.

  9. #9
    Join Date
    Apr 2008
    Location
    Upstate New York
    Posts
    799
    Yup much better ! I know responding is voluntary, you already responded with a hollow opinion w/o back up, that type of response is usless to all of us.

    Im sure you are busy but it sure didnt take long for this response,lol At any rate I read your response but again my house is far from air tight.

    The only reason I was looking at B vent is pipe size and the f'd up way they have to install the fp. Cant bugs and odors enter thru dv pipe or any piping used for waterheaters etc ?

    Isnt there any saftey features on the b vent fp's ? I guess I know how you would feel about vent free then... My brother has a bvent freestandin stove that the bvent goes right up thru the old woodstove pipe so it looks like a real stove, he has never had any issues, is this maore acceptable ?

    No drafts odors etc ??

    Thanks for the response and I wish everyone that responds to a question would do so and back up their response, it would make things much eaiser !

  10. #10
    Join Date
    May 2005
    Location
    Madison, WI
    Posts
    1,078
    Direct vent does not have interaction with the air in the house, intake air (combustion air) goes into the sealed firebox from outside and exhaust goes back outside.

    If a waterheater is B-vent, yes you have all the same problems mentioned above. Many people are installing power vented and direct vent water heaters now.

    The saftey feature is a spill switch, as hearthman said they are setup to allow the appliance to spill CO for 10 minutes before they trip. Do you want ten minutes worth of CO gas in your house?

    There is nothing different about your brothers setup, same technology, same bvent, same issues. Running the bvent up through an old wood stove pipe is like putting poo in a paper bag, it still stinks.

    I don't understand why your dealer is not figuring all this out for you? Did they just sell you a stove and tell you to let them know when you have figured out how to run the venting because they are too stupid to come up with ideas?

  11. #11
    Join Date
    Apr 2008
    Location
    Upstate New York
    Posts
    799
    I havent bought anything yet. Most gas water heaters I have seen are just vented with single wall piping not b vent, how safe is this.

    Again how bout the kitchen range, gas dryer, water heater etc none of these can be good correct ?

  12. #12
    Join Date
    May 2005
    Location
    Madison, WI
    Posts
    1,078
    If its metal it is probably Bvent but you just think it is single wall at a glance. Its a very thin double wall vent. If it is PVC it is a different style of water heater.

  13. #13
    Join Date
    Apr 2008
    Location
    Upstate New York
    Posts
    799
    Nope, its single wall galvinized just like the oil furnaces and the older gas funaces, screwed together every joint, yup just reg single wall galv !

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