| Author |
pre winter wood stove circulation question
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| robson@nf.sympatico.ca 2005-07-29, 10:21 am |
| i have a 2 story house with a wood stove insert in the livingroom /
diningroom. the stove has a blower. the room is approx 15x40'. it gets
very hot in that room and i'm trying to get the warm air to the second
floor. i can't cut vents in the ceiling as the 4 bedrooms are directly
above the main area and it would be too hot. how do i circulate the
heat? i have tried the 2 fans in the doorways of the room to attempt to
get the air up the stairwell to no avail. any suggestions? burning the
stove at a lower temp does not solve the problem. i need to get the
warm air up and the cool air down.
ty
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| nicksanspam@ece.villanova.edu 2005-07-29, 4:21 pm |
| <robson@nf.sympatico.ca> wrote:
>i have a 2 story house with a wood stove insert in the livingroom /
>diningroom. the stove has a blower. the room is approx 15x40'. it gets
>very hot in that room and i'm trying to get the warm air to the second
>floor. i can't cut vents in the ceiling as the 4 bedrooms are directly
>above the main area and it would be too hot.
How about vents with dampers?
Nick
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| barry@sme-online.com 2005-07-29, 4:21 pm |
| You don't tell us the location of the fans.
In a situation similar to yours, sometimes I send some of the woodstove
output up one floor. Natural convection sets up prettty good
counter-currents. Using small fan(s) to boost these currents gets many
times the cfm moving.
IOW, high up, fan discharging heated air away from stove; low down,
opposite direction.
You may want to place small fans in more locations. You may want to
escalate to serious air-movers.
This sort of approach works just fine for me, down to single-digits F
outside.
HTH,
J
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| Colbyt 2005-07-29, 7:21 pm |
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<nicksanspam@ece.villanova.edu> wrote in message
news:dcdk8n$dl5@acadia.ece.villanova.edu...
> <robson@nf.sympatico.ca> wrote:
>
>
> How about vents with dampers?
>
> Nick
>
If you have a forced air furnace that serves both floors just leave the fan
in the on position. Adding a return air register high on the wall in the
room with the stove will help move a little more warm air through the
system.
Hope this helps.
Colbyt
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| Edwin Pawlowski 2005-07-29, 9:21 pm |
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<robson@nf.sympatico.ca> wrote in message
news:1122641554.012817.273560@g47g2000cwa.googlegroups.com...
>i have a 2 story house with a wood stove insert in the livingroom /
> diningroom. the stove has a blower. the room is approx 15x40'. it gets
> very hot in that room and i'm trying to get the warm air to the second
> floor. i can't cut vents in the ceiling as the 4 bedrooms are directly
> above the main area and it would be too hot. how do i circulate the
> heat? i have tried the 2 fans in the doorways of the room to attempt to
> get the air up the stairwell to no avail. any suggestions? burning the
> stove at a lower temp does not solve the problem. i need to get the
> warm air up and the cool air down.
>
> ty
>
Facts:
You will never get the even temperature of a typical house heating system
The cold air is coming down and the hot air is going up. Just not the
volumes you want.
You must move air out as well as more air in to any of the rooms. You can
often help by mounting a small fan in the doorway at the top to blow the hot
air in. This forces the cold air out. It also allows you to hit your head
at times. It was common to put floor vents above the stove and also at the
other end of the house. Ideally it was in a hallway. I'm told this is not
allowed by fire codes though.
You need a series of small fans or ducts to get the distribution that you
need. It will take some experimenting, but you can improve, but never get
full even distribution from a wood stove.
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| nicksanspam@ece.villanova.edu 2005-07-30, 4:21 am |
| Edwin Pawlowski <esp@snet.net> wrote:
><robson@nf.sympatico.ca> wrote in message
If the bedrooms are too cold now and "cutting vents" would make them
too warm, cutting smaller vents (or installing vents with dampers)
would make them "just right," no?
[color=darkred]
>You will never get the even temperature of a typical house heating system
People like cooler bedrooms. How about 5 F less than the living room?
>The cold air is coming down and the hot air is going up. Just not the
>volumes you want.
It isn't hard to estimate the vent sizes needed to keep the bedrooms
65 F with a 70 F living room. Estimate the heat loss from the bedrooms
to the outdoors at 65 F... 880 ft^2 of R20 walls and 600 ft^2 of R40
ceiling would lose (65-30)(880/20+600/40) = 2065 Btu/h on a 30 F day.
And 2065 = 16.6Avsqrt(8')5^1.5 makes total vent area Av = 3.9 ft^2.
>It was common to put floor vents above the stove and also at the other
>end of the house. Ideally it was in a hallway. I'm told this is not
>allowed by fire codes though.
We always have choices.
Nick
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| Edwin Pawlowski 2005-07-30, 10:21 am |
|
<nicksanspam@ece.villanova.edu> wrote in message
>
> It isn't hard to estimate the vent sizes needed to keep the bedrooms
> 65 F with a 70 F living room. Estimate the heat loss from the bedrooms
> to the outdoors at 65 F... 880 ft^2 of R20 walls and 600 ft^2 of R40
> ceiling would lose (65-30)(880/20+600/40) = 2065 Btu/h on a 30 F day.
> And 2065 = 16.6Avsqrt(8')5^1.5 makes total vent area Av = 3.9 ft^2.
>
>
> We always have choices.
>
> Nick
>
Once again Nick dazzles us with his math formula but fails to answer the
question.
Just where and how do you run these vents and the appropriate air handler?
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| nicksanspam@ece.villanova.edu 2005-07-30, 12:21 pm |
| Edwin Pawlowski <esp@snet.net> wrote:
[color=darkred]
>Once again Nick dazzles us with his math formula but fails to answer the
>question.
This answers the question, and the dazzling arithmetic is 300 years old :-)
>Just where and how do you run these vents and the appropriate air handler?
Put the vents in the ceiling. Forget the air handler.
And lose the sarcasm, s'il te plait.
Nick
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| Edwin Pawlowski 2005-07-30, 2:21 pm |
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<nicksanspam@ece.villanova.edu> wrote in message
> This answers the question, and the dazzling arithmetic is 300 years old
> :-)
Sure, but you use it so well.
>
>
> Put the vents in the ceiling. Forget the air handler.
Easier said than done. That is one reason the OP asked the question of HOW?
>
> And lose the sarcasm, s'il te plait.
And Nick is bi-lingual also.
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| nicksanspam@ece.villanova.edu 2005-07-30, 5:21 pm |
| Edwin Pawlowski <esp@snet.net> wrote:
>
>Easier said than done. That is one reason the OP asked the question of HOW?
1. Buy some 12"x4" floor registers with dampers from Home Depot, about $10
for 2 brass-plasted versions for low-traffic areas or $10 for each for
solid brass in high-traffic. OR, buy some $20 13.5"x13.5" Hart and Cooley
registers. Both types fit nicely between joists on 16" centers.
2. Put a supply vent in each room, away from outside walls, ideally near
the ceiling, eg a screen above each bedroom door off a central stairwell,
and install return vents near outside walls by drilling a hole in the
ceiling (taking care to avoid wires and pipes and joists), then cutting
an outline for the register from the floor above with a Sawzall or a sabre
saw with a long blade. Install grates with drywall screws into studs from
above and below.
I did this in a basement ceiling to help warm air move up into a house.
The lower grates weren't required for cosmetics.
Nick
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