Moving air in house?

[Coldfront]

I have a old farm house without very good duct work to the basement, in fact only has one vent for return air and several rooms without any duct of any kind. I was considering some 12 volt computer fans. I have 2 new big 12 volt deep cycle battery's I could recharge at work. I was thinking about 4 of these would move some air from room to room at almost zero cost on my electric bill. Anyone try anything like this?

PRODUCT SPECIFICATIONS
Model R4-S2S-124K-GP
Dimension 120*120*25mm
Voltage 12VDC
Current (Ampere) 0.15 + / - 10%
Input (Watt) 1.8W + / - 10%
Speed (R.P.M.) 1200 R.P.M. + / - 10%
Air Flow (CFM) 44.73CFM
Air pressure (mmH2O) 1.65 mmH2O
Fan Noise Level (dB-A) 19.1 dB-A
Weight 120 g
Available Color black
Bearing Type Sleeve
Fan Life Expectancy 30,000 hours
Connector 3 pin

 

[turnkey4099]

I have a old farm house without very good duct work to the basement, in fact only has one vent for return air and several rooms without any duct of any kind. I was considering some 12 volt computer fans. I have 2 new big 12 volt deep cycle battery's I could recharge at work. I was thinking about 4 of these would move some air from room to room at almost zero cost on my electric bill. Anyone try anything like this?

PRODUCT SPECIFICATIONS
Model R4-S2S-124K-GP
Dimension 120*120*25mm
Voltage 12VDC
Current (Ampere) 0.15 + / - 10%
Input (Watt) 1.8W + / - 10%
Speed (R.P.M.) 1200 R.P.M. + / - 10%
Air Flow (CFM) 44.73CFM
Air pressure (mmH2O) 1.65 mmH2O
Fan Noise Level (dB-A) 19.1 dB-A
Weight 120 g
Available Color black
Bearing Type Sleeve
Fan Life Expectancy 30,000 hours
Connector 3 pin

If by "some" you mean a little bit, otherwise no. It is amazingly hard to move air of any volume in other than ductwork. I have my woodstove in the living room just to the side of the corridor leading to two bedrooms. A 20" box fan hangs in the corridor opening trying to blow air into those two bedrooms - It works but not very well. I should probably move th fan down to near the end of the hallway so it would be pulling air down that corridor.

Harry K

 

[Coldfront]

Last winter I was using 2 big 110 vac fans, sitting on the floor blowing the cold air into the rooms with the wood stoves worked good but my electric bill was $25-$35 a month higher. I have 2 wood stoves, one at each end of the house. I am looking for a way to cut the electric bill. If the four 12 vdc fans work good and can last for say 2 days or more running around 12 hours a day on a charge, I might go with 8 fans and another battery. I can leave battery's charge all night at work, 15 hours if necessary. I think a good deep cycle battery will run these fans a long time on a charge.

 

[greenskeeper]

How many stories? My first house was a rancher with the stove at one end. I was able to put a supply duct directly above the stove and run ductwork to each bedroom. I used small 110v "booster fans" in each run going to the bedrooms. I never saw a difference in my electric bill and I also put the fans on a timer so they would shut off at night when the stove cooled off. Maybe you can do the same thing only run everything in the basement with vents cut in the floor of each bedroom?

 

[taskswap]

I did the math on that one already - it doesn't work well. The problem is the pressure. CPU fans are designed to move air in a very small space. They're totally fine sucking air in from an inch away and dispersing it another inch away, usually through a heatsink... but unless you're going to actually run tubes as ducts from them down a hallway, they don't produce enough pressure to "push" that air far enough (to give it enough inertia) to keep it going on its own. Pressure management is why HVAC duct-work narrows down from the source to the destination - it's trying to keep the same pressure in the tube as the air passes each outlet.

Google around for natural airflow mechanisms. They sound primitive but they actually work shockingly well. It's amazing what you can do with little tricks like cutting holes in the spaces above doorways. That doesn't just let the heat pass from one room to another - it can let you set up natural circulation "loops" that are self-sustaining. Those will outperform any fan, they're just tricky to plan out if your house has an uncooperative shape.

Barring that, consider your verticals more than your horizontals. If you can figure out how air is flowing now and adjust how it moves up and down you can often get a lot more mileage out of it than try to get it moving sideways. Just be careful about randomly opening up vents - that's how fires spread, and it's why we don't cut holes in floors anymore.

 

[Whitespider]

Heat and A/C ducting works because it's a (sort'a) closed loop.
The blower not only "pushes" air, it also pulls air. The blower creates high pressure on the "output" side, and low pressure on the "input" side... the air in the high pressure zone naturally flows to the low pressure zone. The CFM of a fan tells you very little about its performance for the application you intend to use it for. The reason being, the CFM is measured with pressure on both sides of the fan at zero. If you set a fan in, say, a bedroom doorway, once that fan creates even miniscule pressure in the bedroom CFM may drop to near zero (depending on the fan). Computer fans are not designed for use with very much pressure differential, they pull/push air into a case that never pressurizes because of the open venting (they operate at near zero static pressure)... they just move some air over something mounted close, such as the CPU just a few millimeters away.

You need fans with rated CFM @ x-amount static pressure (i.e., furnace blowers)... even your standard 110v box fan fails miserably at any static pressure differential.
With box fans, and worse with computer fans, you'll need two per room... one moving as much air out as the other is moving air in, or the CFM falls flat.
It-is-what-it-is.

Oooopps... it appears taskswap beat me to the punch...
*

 

[brenndatomu]

If by "some" you mean a little bit, otherwise no. It is amazingly hard to move air of any volume in other than ductwork. I have my woodstove in the living room just to the side of the corridor leading to two bedrooms. A 20" box fan hangs in the corridor opening trying to blow air into those two bedrooms - It works but not very well. I should probably move th fan down to near the end of the hallway so it would be pulling air down that corridor.

Harry K

I have found pushing warm air into a room almost impossible, on the other hand, setting a fan in front of the doorway so it is blowing cold air out of the room works much better. Cold air out is displaced by warm air in. Cold air is denser, therefore easier to move, plus it is easier to set the fan on the floor than hanging them all around the house. Blowing cold air at the stove moves warm air better too, even from quite a distance away

 

[woodchuck357]

Last winter I was using 2 big 110 vac fans, sitting on the floor blowing the cold air into the rooms with the wood stoves worked good but my electric bill was $25-$35 a month higher. I have 2 wood stoves, one at each end of the house. I am looking for a way to cut the electric bill.

You must have a very high rate or very inefficient fan motors. For $25 I could run a pair of the 4 foot chicken house fans for a month here.

 

[sb47]

My house is a one story and I have found that like brenndatomu the colder air is easier to move then the warm air. I lit a cigarette and slowly move it up and down in a doorway. By doing this it is easy to see how the air layer moves in and out of a room with no fans running. At the top of the door where the warm layer is it will flow one way and at the bottom it flows the other way.
I took an old fan out of an outside ac unit that came off the evaporator coil. You know. the one that pulls the air through the outside unit.
It moves a lot of air and doesn't cost a lot to run. I built a box for it, so its like a box fan, but it moves a lot more air and is very quiet. You almost cant hear it running but it moves a bunch of air.
I put caster wheels on it and just put in a door way pulling the cold air out of the room and it lets the warm flow over the top.
Its kind of like using the natural convection airflow that naturally moves the air around and just boost it up with the fan.
Seems to work pretty well. I like my bedroom colder then the rest of the house any way so this works for me.

 

[Ironworker]

Air moves naturally quit easy, easier than some on here would lead you to believe, one small fan far away from your stove pushing cold air to your stove should be all you need. Just walking around and opening and closing doors moves air.

 

[Fred Wright]

Well.... carrying a deep cycle battery to work and back all winter would get old fast I'd presume. And yep, the little CPU cooling fans really don't move much air volume anyway.

I've found that to move warm air to outlying rooms, a box fan or blower on the floor, facing in the direction of the stove works pretty well. Blowers are typically noisier than fans but they can be aimed more precisely. The ticket is to move cold air out of a room. Warm air comes in to replace it.

Floor drying blowers are available that would be perfect for this application. Check 'em out at Amazon: http://www.amazon.com/s/ref=nb_sb_s...rying+blower+fan&sprefix=floor+drying,aps,157

 

[Ironworker]

Well.... carrying a deep cycle battery to work and back all winter would get old fast I'd presume. And yep, the little CPU cooling fans really don't move much air volume anyway.

I've found that to move warm air to outlying rooms, a box fan or blower on the floor, facing in the direction of the stove works pretty well. Blowers are typically noisier than fans but they can be aimed more precisely. The ticket is to move cold air out of a room. Warm air comes in to replace it.

Floor drying blowers are available that would be perfect for this application. Check 'em out at Amazon: http://www.amazon.com/s/ref=nb_sb_ss_i_3_12?url=search-alias=aps&field-keywords=floor drying blower fan&sprefix=floor drying,aps,157

I've used those floor drying fans and they use alot of power.

 

[sb47]

For some reason my camera doesn't always work but I did get a video of the fan that I made.
Its quiet and moves a lot of air. Its been sitting in my shop all summer so I need to clean it.
It fits just rite in a doorway and this is what I use for a fan.
I use it to pull cold air out from the bottom and let the hot air over the top in a doorway.
It was cheap to make and works well for me.

View My Video
View My Video

 

[husky455rancher]

i have a killawatt. its a devise that measures how much electricity something uses. im suspecting you think a fan uses far more power than it actually does. my 10k btu ac uses about 750 watts. if i just run the fan its about 50 watts. i dont see a plain old fan using anywhere near that much power.

 

[sb47]

The fan that I'm using has several ways to hook it up. It has three speeds depending on how you wire it up.
I have it wired up on the lowest speed.

 

[sb47]

It would be interesting to see how much this fan draws. I wish I had one of those measuring devices. Not gonna buy one. I wonder how long this fan would run for the cost of that watt meter? lol
It cant draw much on low speed.
Might just paint her up before I bring it in the house this winter.
I' have to find some old paint. Not gonna buy that ether. lol

 

[sb47]

I agree a PC fan is not designed to move much air.
Its hard to find fans that move a lot of air that are quiet.
The ones that have the weird pointy fan blades seem to be the quietest I have found.
Just go to the fan department at wall-mart and try them out.
They had a whole bunch of them set up at my local store.
Its surprising to see how much different they all are.

 

[mga]

i use a furnace inducer blower to draw cold air from the furthest part of the house. cheap to buy, quiet and cheap to run.

but, I'd look into running some duct work around that house if possible.

 

[aaron]

I have a split lvl home with my Buck 75 in the lower lvl. I use a small 9" fan at the top of the stairs blowing towards the stove. You can feel the warm air coming up the stairs as you walk down.

 

[v8titan]

http://www.target.com/p/honeywell-t...pid=11153539&gclid=CNHG_ZvzpMECFZSPfgodwxAAOg

This fan works real good, put it on the floor and blow the cold air toward the heated room.