Baro Question I Have Not Seen
- jpete
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I know all the recommended locations for a baro but I was talking about it with a friend and he asked a question I couldn't answer.
Why can't you "T" off the stove pipe, and run the baro down near the floor?
His reasoning is that when the baro opens, it sucks some of the already heated air out of the room. If you have to take air out of the room, why not use the cooler air down by the floor?
We were talking because I will be finally adding a baro to my setup this weekend to see if it runs any better than just the MPD(which I'm pretty happy with).
Thanks
Why can't you "T" off the stove pipe, and run the baro down near the floor?
His reasoning is that when the baro opens, it sucks some of the already heated air out of the room. If you have to take air out of the room, why not use the cooler air down by the floor?
We were talking because I will be finally adding a baro to my setup this weekend to see if it runs any better than just the MPD(which I'm pretty happy with).
Thanks
I guess if you pipe it properly so no fly ash can build up in the lower pipe, it can be done. But, I really don't see the added benefit of doing so with the expense of more pipe and space it takes up. There can't be that much of a difference. Besides, I would definitely not mount it lower than 18" off the ground if you store any flammable liquids or gases near or in the same area. The gases may get sucked up into the chimney. Something to think about.
I would think it would work better. The baro uses cooler room air to act as "block" to the warmer combustion gas in the
pipe. Pulling cooler air from the bottom of the room would make the "block" even more effective. Maybe so much so that
you would want to re-check flue flow after the switch to cooler air.A guess at best....
pipe. Pulling cooler air from the bottom of the room would make the "block" even more effective. Maybe so much so that
you would want to re-check flue flow after the switch to cooler air.A guess at best....
I was going to do something like that when I ressurected my stoves that I stopped using 20 odd years ago. My brother has always had his set up with the baro in the basement clean out door, stove on the first floor of a center chimney cape. His burner guy set it up with a manometer and he keeps a good differential between the pipe at the thimble, and the stove top.
If youthink about it, the baro in the cellar will tend to pull cold air off the floor and replace it with warmer air infiltrating down to replace it.
My way of thinking is that the baro cuts the high draft of a hot chimney, and allows the hot exahust of the stove to stay in the stove longer, transfering more heat to the metal. Also keeps the chimney from increasing the draft rate when the wind howls over the top. You can see this happen when you watch the manometer on a windy day.
I chickened out and put them in the usual manner, above the stoves.!!
Be interesting to hear what others think about it.
Paul
If youthink about it, the baro in the cellar will tend to pull cold air off the floor and replace it with warmer air infiltrating down to replace it.
My way of thinking is that the baro cuts the high draft of a hot chimney, and allows the hot exahust of the stove to stay in the stove longer, transfering more heat to the metal. Also keeps the chimney from increasing the draft rate when the wind howls over the top. You can see this happen when you watch the manometer on a windy day.
I chickened out and put them in the usual manner, above the stoves.!!
Be interesting to hear what others think about it.
Paul
- Freddy
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Give 'er a try & let us know how it pans out. It'd be interesting to see an actual scientific study.
Maybe run it down to the floor, then out the wall....suck in outside air... or... run it to the neighbors living room, suck his warm air, Yaaaa, that's the ticket.
Maybe run it down to the floor, then out the wall....suck in outside air... or... run it to the neighbors living room, suck his warm air, Yaaaa, that's the ticket.
-
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I think the baro works, at least in part, by the velocity of the gas flowing past it. That's why the Field Controls baro has different weight positions for mounting in a vertical pipe vs. a horizontal pipe, and why it is mounted close to the gas stream.
The other thing the baro responds to is the pressure differential between room air and chimney -- the "draft" measured in inches of water column or whatever it's called. That's why it opens quickly when a wind gust increases suction at the chimney top.
The average reduction in draft, caused by mixing cooler air with the hot flue gases, is an incidental effect that can actually be a drawback rather than a benefit if your typical draft is too low on warmer days.
So that's the theory, as far as I understand it. I suspect it would work sort of OK with jpete's suggested location, but not as well as in the recommended locations.
The other thing the baro responds to is the pressure differential between room air and chimney -- the "draft" measured in inches of water column or whatever it's called. That's why it opens quickly when a wind gust increases suction at the chimney top.
The average reduction in draft, caused by mixing cooler air with the hot flue gases, is an incidental effect that can actually be a drawback rather than a benefit if your typical draft is too low on warmer days.
So that's the theory, as far as I understand it. I suspect it would work sort of OK with jpete's suggested location, but not as well as in the recommended locations.
- coaledsweat
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The baro cannot be lower than the lowest point of the stovepipe. It also must be close to the exhaust gas stream, so elbows and extensions will not be a good idea. See the Field Controls website for installation instructions.
Do not attempt to mount the baro in this fashion is my advice.
Do not attempt to mount the baro in this fashion is my advice.
-
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In another thread, I was told flatly that the baro would not work if sucking outside air, because it depends on being at the same air pressure as the stove itself. I haven't quite accepted that in my own mind -- I need someone to draw me a picture! However, think of a strong wind blowing against the side of your house where the baro intake is located. The air pressure will be significantly higher there, forcing air into the chimney system and consequently pressurizing the inside of your stove. Or a wind blowing past the baro intake, creating a suction and reducing the chimney draft. Seems like either sort of wind would be a problem. Only on a still day, when inside/outside pressure would be the same, it might work.Freddy wrote:Maybe run it down to the floor, then out the wall....suck in outside air
- WNY
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I would NOT run outside air, your pressure could equalizer, since now the top of the chimney and the other pipe are both outside and you could reverse flow out the baro and now you have 2 pipes sucking your exhaust and could be dangerous.
Even using the TEE instead of an elbow is NOT recommended from Field Controls. For proper flow and operation, there should be a straight section before and after the baro. So there is no turbulent air flow in the pipe. When it has to change directly as in the TEE (in place of an elbow) it may not give you a good reading. I also ran this by some engineers (air flow) and they agreed.
It would still work(like many have done on here), just may not be optimum.
Even using the TEE instead of an elbow is NOT recommended from Field Controls. For proper flow and operation, there should be a straight section before and after the baro. So there is no turbulent air flow in the pipe. When it has to change directly as in the TEE (in place of an elbow) it may not give you a good reading. I also ran this by some engineers (air flow) and they agreed.
It would still work(like many have done on here), just may not be optimum.
Ditto Also putting your Baro at the bullhead on a T is not allowed. But many here do it. Including myself.coaledsweat wrote:The baro cannot be lower than the lowest point of the stovepipe. It also must be close to the exhaust gas stream, so elbows and extensions will not be a good idea. See the Field Controls website for installation instructions.
Do not attempt to mount the baro in this fashion is my advice.
- coaledsweat
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It may go in the upper elbow (with TEE) of your pic as many here have mounted them. The first elbow of the unit would be an absolute no-no as the gas stream runs directly into the baro's plate, that would leak combustion byproducts into your home. They really are designed to read the pressure differential from a side stream feed. That is the best way to mount them which is not always the most conveniant however.cArNaGe wrote:DittoAlso putting your Baro at the bullhead on a T is not allowed. But many here do it. Including myself.
- oliver power
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I'll give this a try. No reading, or research. Just a common sence guess. I would say not to put the barodamper at the floor due to colder air being heavier than warmer air. When the wind blows, the chimney draws (sucks) harder. Normal baro damper installation would allow cooler air to be drawn in sideway, above fire. It would take more suction to draw the colder heavier air up off the floor, than it would the warmer air comming from stove. Therefore, the chimney would draw more heated air easier from the stove, than cold air from the baro damper at the floor level. I would agree with the static preasure therey also.