through the wall air passage/fan

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stovepipe?

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Dec 1, 2005
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I have my stove in a medium sized room with fairly tall ceilings and a couple of doorways. One of the doorways goes right out to the stairs. When I can get some air flowing through that door, it moves nicely up the stairs and heats the second floor very well. The ceiling is high enough that a lot of warm air pools in the two feet above the doorway (stand on a chair and the temp at your head feels 15 degrees higher than at your feet). I have been using fans stuck in various spots and it has worked okay. However, I don’t really like all the fan clutter, and even with it, the heat motherlode in that two foot zone at the ceiling remains untapped. I know I could just use one of those doorway fans, but they are not the nicest looking things and I don’t have a convenient outlet anyway.

So here’s what I want to do: I will cut through the wall above the doorway just below ceiling level to make an air passageway and will cover with vent grates. I would like to keep this small, if possible, but also efficient. The ideal setup would be a small passageway enclosed with vent grates with a fan inside to pull the air through. So my question: does anyone know of a good fan for the job? I can’t seem to find much of anything. The best I’ve come up with is one of those small door fans wired in the wall and controlled from below with a lightswitch. But this strikes me as a little half-baked. I would think there is something out there built for this purpose, but can’t seem to find anything. Anyone know of anything?

Also, suggestions/recs on my proposed set up would be great—i.e. will/won’t work well, good alternatives, etc.

thanks
 
You can put some large computer style fans if you can get some wiring in the wall to the hole, also you can just run your furnace fan without the heat on to circulate the entire house.. Minuteman hearth products makes some nice grates to use on the holes, and i also believe they make fans.
Ryan
 
I have steam, not forced air, so no furnace fan. what to you mean computer style fans? I can get the wiring there. where would I find such a thing? if it is what it sounds like (reasonably strong, small and quiet), sounds perfect. I'll check out minuteman-- thanks.
 
You can buy large ones from a electronic supply store. They have them in the 400 cfm range. here is what im talking about. (broken link removed). They are very quite. I would buy one local if you can, that way you can see exactly what your getting, make shure you get one for 120v.

Ryan
 
stovepipe? said:
I have my stove in a medium sized room with fairly tall ceilings and a couple of doorways. One of the doorways goes right out to the stairs. When I can get some air flowing through that door, it moves nicely up the stairs and heats the second floor very well. The ceiling is high enough that a lot of warm air pools in the two feet above the doorway (stand on a chair and the temp at your head feels 15 degrees higher than at your feet). I have been using fans stuck in various spots and it has worked okay. However, I don’t really like all the fan clutter, and even with it, the heat motherlode in that two foot zone at the ceiling remains untapped. I know I could just use one of those doorway fans, but they are not the nicest looking things and I don’t have a convenient outlet anyway.

So here’s what I want to do: I will cut through the wall above the doorway just below ceiling level to make an air passageway and will cover with vent grates. I would like to keep this small, if possible, but also efficient. The ideal setup would be a small passageway enclosed with vent grates with a fan inside to pull the air through. So my question: does anyone know of a good fan for the job? I can’t seem to find much of anything. The best I’ve come up with is one of those small door fans wired in the wall and controlled from below with a lightswitch. But this strikes me as a little half-baked. I would think there is something out there built for this purpose, but can’t seem to find anything. Anyone know of anything?

Also, suggestions/recs on my proposed set up would be great—i.e. will/won’t work well, good alternatives, etc.

thanks
Click to expand...


It is called a door transom. Older buildings all had transom over the doos to aid in the movment of air.
Not only will you better heat flow your cooling efforts in the summer will benefit too.
 
i thought of the b-room fan, but they all seem too big and, more importantly, too thick-- it has to fit within a 5 inch thick wall. but if you know of some model that might work, it certainly is an option. I like the computer fan idea-- any thoughts on how much air I will need to move to make it worthwhile? It is mainly an issue of getting it from one side of the transom (my new vocab word of the day) to the other, and I think natural drafts will do the rest.
 
for refrence, alot of blowers for stoves are in the 180 cfm range. These fans have ball berings, so there quite, but wind noise can get up there in the high cfm range. I would buy the highest CFM rating you can find and put it on a wall dimmer switch. That way you can control the noise and and airflow.
RYan
 
If I were you I would wait to buy the fans until you get the hole made and grates up. You might be pleasantly surprised how that warm air wants to go to the cooler air on the other side of the wall. I don't think you will need any fans. Homefire alluded to the fact that what you are trying to do was done long ago before central air took away the need.
 
I got some muffin fans from a guy at work when he was taking apart one of the conveyor lines. After I get some more stuff done to the house I'm going to put one in each bedroom to bring air in from the hallway. They're very quiet and can move a significant amount of air. (a 100 cfm fan will move all of the air in a 12x12x8 room in 11.5 minutes). I'm planning on installing mine hardwired into the house on a rheostat so I can control the fan speed. He said he did the same with some at his brother's house and it helped heat the room up quickly.

http://www.mcmaster.com/ctlg/DisplC...th=812&ToolsetID=ToolMultiPageNav&ToolsetAct=

The next page (593) has covers for them.
 
Lets look at your situation: First you have to determine if it doable.
If that wall is a bearing wall, then the header above is solid structural bearing and should not be cut. If non-bearing then there will be a cavity there.. One could try the passive route. The heat side installs the grill fins facing up. The area you want to direct the heat two the other side of the wall the grill fins down. Unfortunately you are only looking at part of the solution. Warm air rises and it is extremely difficult to make it descend. All your efforts will be having warm air trapped at ceiling level on the other side of the header. The key is drawing it down. One way is to remove the lower level cooler heavier air, which gets replaced by the lighter warmer air. Your effort to achieve air distribution has to focus towards moving the cooler air.

If you setup the grill system as I had suggested, and place a box fan on the floor aiming down your stairs, You will create that convection of drawing the warmer air down.

I have said this many times homes with ceiling returns suck for heating purposes. Great for AC. For some reason not a lot of thought goes into system designs on the return side. Yea there are plenty of supplies so much so they are trying to bludgeon the heat to descend. Every summer I get called in to figure why the attic AC unit freezes up at someone’s home. The attic is over 120 degrees yet the AC unit is encased in ice? Why inadequate returns, number one culprit. . With second floor ceiling returns how does the upstairs heat? The lower level heat you feel is coming threw the floors and being heat from the lower zone. Move the upper level thermo all you want but if you are returning that same heated air it is never getting drawn down.. Solution is High low feeds and returns spaced to promote air circulation.
Heating requires removing cooler air so simple The CFMs and fans moving the warm air theory will not be that sucessfull
All it will do is mix some of the air in the upper levels Possibly expanding that area down.
 
Elk,

He's probably got 9' ceilings like I do, that leaves plenty of room to put a grate in. The space between the top of the doorway and the ceiling is locking in the heat. As far as worrying about the cold air return, if warm air is moving in at the top normal convection will force cold air out at the bottom. I don't see a problem. Even with no fans he will have a different temp at the top than the bottom but never the less it will be warmer overall. He's just trying to get warm air up the stairs at the top and cool air will come down at the bottom of the stairs. Warm air wants to rise and cold air wants to sink naturally no fans should be needed.
 
I do indeed have 9’ ceilings. descending isn't such an issue I think since once the warm air is on the other side of the doorway, it can flow along a three foot wide section of ceiling and up the open staircase-- make sense? so the point is for it to continue up, unimpeded to the second floor and once it's past the doorway, there is nothing to trap it one the first floor. I have tried moving the cold air as suggested-- fan pointing down the stairs, but currently I get the best results when I can pull hot air away from the stove and through that doorway, letting the hot air take care of the rest. Most efficient way to do this, I would think, would be to pull the air from one side of the transom to the other. sound reasonable?

by the way, thanks to all for the good suggestsions-- computer and muffin fans certainly weren't on my radar
 
stovepipe? said:
I do indeed have 9’ ceilings. descending isn't such an issue I think since once the warm air is on the other side of the doorway, it can flow along a three foot wide section of ceiling and up the open staircase-- make sense? so the point is for it to continue up, unimpeded to the second floor and once it's past the doorway, there is nothing to trap it one the first floor. I have tried moving the cold air as suggested-- fan pointing down the stairs, but currently I get the best results when I can pull hot air away from the stove and through that doorway, letting the hot air take care of the rest. Most efficient way to do this, I would think, would be to pull the air from one side of the transom to the other. sound reasonable?

by the way, thanks to all for the good suggestsions-- computer and muffin fans certainly weren't on my radar
Click to expand...

If you cut transom then a slow turing ceiling fan will do the rest.
Slow turn being the key to moving the air through the transom just like in the Texas State Capitol Building.
They have Hunter fans there from the 1800's .
 
If you need a fan solution here is a link to a wall register with fan built in. They also have the grates and registers that Mountainstoveguy was talking about. I like the look of the antique grates. Here ya go...


(broken link removed to http://www.northlineexpress.com/detail~PRODUCT_ID~5SA-4015.asp)
 
I was searching through the posts and I found your post. I am looking to do the same thing to move air into a room. I realize that the post is almost 1-year old, but i have a source where you can get the fans you were looking for. These fans are call axial fans and are extremely quite - barely noticeable. Axial fans small but they move 105 cfm. I am planning on putting two of these inside a frill also. Check it out.

(broken link removed)

Unless you plan on hardwiring the fans, you will also need power cords also.

(broken link removed)

i hope this helps. Can you please let me know if you ever got this to work out for you. I wouls really love to know and maybe see pictures.

I currently have 3 axial fans hund from the ceiling of our hall way to pull warm air down towards the bedroom corridor.
 
I've used these fans in an old house with a Resolute. They are nice and quiet and do work. Also called muffin fans. But after experimentation I found the worked a bit better by locating them low and pointing them so that they blow towards the stove. That created a much better convection loop. Put a digital thermometer near the end of the bedroom corridor and measure the temp with the current setup. Then try reversing the fans and lowering them temporarily. After an hour, measure the temp again.
 
have been for years, read back on original threads.
 
If air share is the plan ,remember you just lost a lot of privacy, by creating noise transmission passage ways
 
elkimmeg said:
If air share is the plan ,remember you just lost a lot of privacy, by creating noise transmission passage ways
Click to expand...
Not perfect but a lot less Noise and sound travle that the other ROOM TO ROOM type like NUTONE has.
the Airshare has a off set installation.
With the top to bottom or Bottom to top type install
you will have a buffer between the two because they are not across from each other.
No light will pass either. The fans

Here is links to the install manuals
http://www.tjernlund.com/Tjernlund_AS1_AireShare_8504136.pdf
and the plug in type
http://www.tjernlund.com/Tjernlund_AS1P_AireShare_8504137.pdf
 
Those do look like neat units, what sort of price would one be looking at for them? I realize different places will want different amounts, along with install costs, but it would be nice to know what the "ball park" price is.

The other thing that I was wondering about if doing an offset installation is that many homes are built with fireblocking in the stud spaces - wouldn't that pose a problem?

Gooserider
 
$230 for the Non switch unit
$290 for the switched with plug in

(broken link removed)
go to page 808
 
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