Our 'freezing floor/hot ceiling' problem solved

[Québec]

Tried an experiment today.

We have a 40' trad, 4kw stove at the front + an Ecofan (I know, don't go there).

Bought a couple of 8cm 12v computer fans. Installed one in the ceiling (using a light fitting hole above a window) just in front of the stove.

Temperatures 1m from stove, before switching on: floor 8C head height (we're both short-arses) 24C ceiling 29C

Temperatures after switching on and leaving for an hour:

floor 18C head 23C ceiling 28C

 

Success....I think.

Edited January 24, 2015 by Québec

[GoodGurl]

great idea, we had thought of this but by putting the fan over the doorway, is your fan sucking cold air up or blowing hot air down.

[Québec]

Blowing hot air down.

[DeanS]

well done. I'd say that's a result:)

[MtB]

And how about further back in the boat?

 

I'm puzzled why your fan makes any difference at all actually, as there is probably very little air supply to feed it from behind the ceiling panelling.

 

 

MtB

[Québec]

Temporary fitting.

 

Mike...actually plenty of air behind the 'lighting plank' due to my imperfect workmanship! :-)

 

 

https://www.facebook.com/photo.php?fbid=10153079432142959&l=f082253996

Edited January 24, 2015 by Québec

[Bettie Boo]

BRILLIANT!!!

 

We have the exact same issue. The floor (actually, about a foot & a half up from the floor) is noticeably colder than the rest of the boat. To the point we can be sitting in the saloon and where it's getting to the point of being uncomfortably warm, but I need to have slippers and socks on as my feet are always cold.

 

Sending Dave to find a Maplins first thing on Monday. Since we don't use the top lights in the saloon at all & just happen to have a light fitting almost directly above the stove it sounds like a perfect solution

 

Thank You for sharing this

[Québec]

And how about further back in the boat?

 

MtB

Not that bothered, really. More important is where we sit most of the time.

Edited January 24, 2015 by Québec

[davidb]

well done, see how warm your feet are at 10 oclock tonight, that will prove it. Let us know, you might start a trend.

[David Mack]

How high is the stove off the floor? Since hot air rises its never going to get very warm below stove level yet people fit them, sometimes on raised plinths, at the high end of the boat! Cold feet are inevitable in some boats.

Edited January 24, 2015 by David Mack

[Québec]

How high is the stove off the floor? Since hot air rises its never going to get very warm below stove level yet people fit them, sometimes on raised plinths, at the high end of the boat! Cold feet are inevitable in some boats.

Hearth is 10cm high.

Grate is 27cm above floor level.

Current temp on floor @ 19:45hrs 20C (tested with 2x thermometers).

[b0atman]

I use USB fans from amazon.

[onionbargee]

 

 

Don't go to maplins or PC world for PC fans, they are horrifically over priced, you can get them on eBay for 99p including delivery. Or any computer repair shop will give you them for free if you are prepared to salvage them out of an old PC tower.

[wishful]

Hi everyone.

 

This is my first post on here so please go easy!

 

I can appreciate the problems of cold feet and hot heads having spent a fortnight or so on a 60 foot narrowboat last winter heated only by a woodburner. With a friends help, we rigged up a 12v pc fan inside a length of plastic drainage pipe of internal diameter 100mm. At the very ends of the pipe, which stretched from ceiling to floor, we cut away an arch about 100mm high. Much like the OP's suggestion, this mixed the cold and warm air reducing the stratification hugely.

 

The benefit of using the pipe over a non-ducted system like that described above is that a fan in a pipe circulates the coldest of the air drawn only from floor level, mixing it with the very warmest at the ceiling.

 

One enhancement could be to strap a metal (not plastic!) pipe to the back of the flue which would, perhaps, eliminate the need for any fan; the warming air would reduce in density as it rose up the pipe (heated by the flue) thus drawing in more cold air at the bottom. Concerns about soot build-up in the flue would be minimal, and could be eliminated by including a small spacer between the flue and the pipe.

 

Any thoughts about either of these solutions?

[dor]

Last winter I hung a 100mm computer-type fan about a foot or so below the roof towards the back of the saloon. Running it certainly made a difference; it was a relatively powerful fan, drawing about 0.5 amps. I also had one a bit further back, lower powered at about 0.1A, blowing down the boat. They certainly seemed more effective than the ecofan, but nosier and not so good at telling you if the stove was going out.

 

I still have plans to make them more permanent and more effective, although my plans haven't got quite so far as working out how to do it that would be aesthetically pleasing. I wish now that I had installed some ducting behind the panels when I fitted out the boat.

[Top cat]

I've hung a couple of computer fans wired in series (to quieten them down) behind and just above our corner mounted stove. I arrived at that location after many experiments and think this is better than having them up high. By having them low you push the warm air out into the saloon before it rises. My fans are hung from tie wraps that go to hooks on the wall to provide some acoustic isolation. Elastic bands work better but dont last long. I didhave them in a duct for a while but didn't find it gave much benefit.

 

Top Cat

[Phil Ambrose]

I've hung a couple of computer fans wired in series (to quieten them down) behind and just above our corner mounted stove. I arrived at that location after many experiments and think this is better than having them up high. By having them low you push the warm air out into the saloon before it rises. My fans are hung from tie wraps that go to hooks on the wall to provide some acoustic isolation. Elastic bands work better but dont last long. I didhave them in a duct for a while but didn't find it gave much benefit.

 

Top Cat

What you are describing is exactly what an Eco fan does, it disrupts the thermal pattern of the hot air around the stove and pushes hot air away allowing cooler air to replace it which in turn becomes warmed etc etc.

Phil

[Top cat]

Yes and at a tiny fraction of the cost and without taking up valuable stove top space.

 

T C

[MtB]

Yes and at a tiny fraction of the cost and without taking up valuable stove top space.

 

T C

 

 

And with the major drawback (for me at least) that your computer fans don't gently broadcast the shifting condition of the stove combustion as the hours pass...

 

I generally notice the stove needs adjusting or more fuel from the speed of all the Sterling and Eco fans cluttering up my stove top .

[larkshall]

And with the major drawback (for me at least) that your computer fans don't gently broadcast the shifting condition of the stove combustion as the hours pass...

 

I generally notice the stove needs adjusting or more fuel from the speed of all the Sterling and Eco fans cluttering up my stove top .

If of course you invert the hull, you will have the same effect. Mind I suspect the fans will stall

[Phil Ambrose]

Yes and at a tiny fraction of the cost and without taking up valuable stove top space.

True about the cost, however once you have an Eco fan all you have to do is put it on the stove top and away it goes, no fans to fix to bulkheads or ceilings, no wiring, and silent. As for the stove top space, we use a gas hob which works very well and we don't have to lug kettles of boiling water through our saloon with the inherent risk of tripping on one of the dogs, but each to his own.

Phil

 

T C