Pulling heat through an enclosed floor plan...

[Wet1]

I will be removing our pellet stove from the basement and installing one on the first floor to hopefully gain some efficiency. We have an older house with a fairly enclosed floor plan on the first floor, which is about 1000 sq ft. The central stairs going to the basement and to the upper floors both have doors on them which can be closed off, I'm going to close them both because I'd like to try to essentially isolate the heat to the 1st floor only. Since the floor plan is not open and the stove can't be placed in a central location, I need to figure out a way to distribute the heat. Attached is the basic layout of the 1st floor (not to scale). The central staircase will be closed off and the bathroom in the center is closed off on three of the four sides. I've never liked having the central staircase/bathroom, but I think this just might work to my advantage since it could allow me to pull the air around the perimeter. What I was thinking about doing is installing a 16" shrouded window fan (which I have kicking around) in a door at the noted location. I would obviously have to cut a large hole in the bottom of this door to install the fan, but I don't mind doing this since the door itself was removed a while ago anyway. The fan would be blowing in the direction indicated. The large room next to the stove has a 7' archway right next to the stove itself so I'm sure that room will stay plenty warm, even though the fan should be pushing the air back towards the stove. The far rooms OTOH are going to be somewhat isolated from the stove...

My question is do you think this single 16" fan at the proposed location will be enough to pull the warm air around the layout and keep the farthest areas warm? Thoughts or suggestions?

 

[Shortstuff]

I'm no expert, but it looks like a plan I would consider too. To encourage good air flow, I might want to add another small fan to the lower-left of your diagram, like those small door fans that tuck up in the corner of the doorway.

Other than that, from all that I've learned, I think you'll be in good shape.

Steve

 

[Wet1]

I've never used those small corner fans before, but I've always questioned how much good they would be. Without being shrouded, it seems to me the air would basically circle around the doorway and not move all that much air from one room to the other... not to mention they are pretty small fans. I'm hoping the 16" shrouded fan will be enough to move the air around the house on it's lowest setting, if not I know it moves a good amount of air at its higher settings. I could add another fan in that same door if need be, but I don't want to get to the point where I'm dishing out another $100 every month for the electric bill either.

I use this same 16" fan in a window located at the top right of the diagram during warm weather. I have it set to exhaust warm air in the evenings out of the house and it does a nice job of pulling cool exterior air from the windows located at the bottom left of the diagram, so I'm hopefull it will circulate air around the closed off house as well.

 

[Shortstuff]

Myself, I'm actually going to try a couple of computer cpu fans that are not too small either. They are extremely quiet, move a good amount of air and are very economical to run. All in all it doesn't take a lot to get a mild (barely noticeable) airflow going. If you move the air too fast it's going to cool down which is contrary to what you want. Almost like the natural flow of heat rising, that is the ultimate goal for you, to move the heat in a circular pattern, but not even "feel" the airflow at the same time.

Steve

 

[Wet1]

Good point Steve. You're right, you don't want the air moving around the house too quickly. I like that larger fan because it's really quiet on it's low setting and still moves a decent amount of air... maybe to much. I should probably start with a smaller shrouded window fan (like a 10") in that door before I cut the hole for the larger fan...

 

[MCPO]

Personally I think a fan nearer the floor to act as a cold air return would work better than trying to push heated air a long distance.
Let the cold air gently push the warm air back to the stove.
John

 

[MCPO]

Personally I think a fan nearer the floor to act as a cold air return would work better than trying to push heated air a long distance.
Let the cold air gently push the warm air back to the stove.
It`s still gonna be tough having to get heat thru 3-4 door openings.
John

 

[begreen]

Try a portable box fan or a large table fan first. They move a lot of air on low and work well placed on the floor. Experiment with locations. Try the location indicated on the drawing. Also maybe try it blowing towards the stove from the "this wall to be removed" location. That will reverse the airflow. See if that makes the large room with the bump out more comfortable.

Removing the wall should help, maybe make that the summertime project? It looks like it could be load bearing. If it is, a large open archway with a stout carrying beam should be as effective. That's what we ended up doing.

 

[stoveguy2esw]

i would not try to move it in a circular fashion as you depicted, the hot air escapes over the top of the cold air entering. move cooler air near the floor into the room or warm air up high out of the room through both openings. you will get better results that way than trying to move the whole air mass in a whirlpool fashion.

 

[Wet1]

I know this is an old thread, but I wanted to give some feedback as to how this worked now that we've had several days of cool weather to fully test it.

First, I should say that I located the 16" (?) shrouded fan in the doorway to the left of the one in the proposed drawing. I also located the stove a few feet 'above' where I drew it in the attached drawing, so it's just on the other side of the archway in the larger room. The wall that I mentioned will be removed in the future, still has not been removed (and probably won't be removed anytime soon).

In a nutshell, this works very well.

I tried running the stove with no fans circulating the air, as you might expect, the warm air didn't make it to the left side of the drawing... hardly at all.

I next tried blowing two fans in the door and archway, located on the floor, blowing back towards the stove. This helped warm the two small rooms next to the stove, but the left side of the drawing remained pretty cool.

I then tested this circular airflow proposal. I was quite impressed as it does a noticeably better job of circulating the warm air around the first floor of the house when the other levels are sealed off. Now that we've had days of cool weather, I can confirm this method works very well if your floor plan is such that the air can be forced around a loop. I'm seeing a 4*F temp drop from the room where the stove is located to the returning cold air entering back at the same room. Given the distance and the compartmentalized layout, I'm amazed there's only a 4* delta with outside temps in the mid 30's.

The down side is the 16" fan is moving so much air around the house that you can feel a slight draft in the smaller rooms, even with the fan on its lowest setting. Lighting a lighter in any of the doorways proves the air is being pulled around pretty good, enough to bend the flame about 5 to 10 degrees anywhere within the doorway. I tried shrouding a 10" fan in the same location, but while the draft was almost gone, it didn't pull the heat around nearly as well either.

Overall I'm going to say this technique has proven to work even better than I expected it to. I do expect to see more than a 4* F delta as outside temps drop even further, but the heat is definitely making it to the other side of the floor plan using this method.

 

[CygnusX1]

I have 2 of these fans that work pretty well.

(broken link removed to http://www.northlineexpress.com/itemdesc.asp?ic=5SA-4001)

You don't need a huge fan to create a current in the house, a 50-75 CFM fan is plenty. The trick is to blow cold air towards the stove and place the fans as close to the floor as you can. I've found that this will create a perfect current for heating my kitchen, raising the temp almost 10 degrees.

 

[sydney1963]

I have a similar floor plan and have never used a fan. Just remember cold air sinks and warm air rises. In my home I can feel the air currents moving, I'm surprised you don't.

 

[Shortstuff]

Thanks for the update Wet1, it's always good to find out how an idea works out. Of course no two houses are identical and the results can be very different in other locations, but at least it's feedback from first-hand experience.

Happy heating!

Steve

 

[Wet1]

I have a similar floor plan and have never used a fan. Just remember cold air sinks and warm air rises. In my home I can feel the air currents moving, I'm surprised you don't.

I tried w/o the fan, but my floor-plan is just way to restrictive and compartmentalized (small rooms, doorways, and jogs) to allow the heat to really make it to the other side of the house. W/o the fan I was seeing major temp drops of 10 to 15 degrees, and the outside temps aren't even all that cold yet. I can feel the air moving w/o the fan, but it's only on the one side of the house, the other just gets cold.

Locating two smaller fans at either end of the stove room (on the floor pointing back at the stove) did improve things, but it still didn't work nearly as well as forcing the air around the house. I think the real trick is having the shroud around the fan and across the doorway, without the shroud it didn't work at all. With the shroud, the pressure differential really pulls the warm air around the house.

Anyway, I'm sure this isn't for everyone, but I thought I'd update this thread for someone else who might benefit from this little experiment.