Hi,
I was watching that program on BBC2 "It's not easy been green" and I saw that they piped the warm air from the kitchen where the wood burner is, up stairs to the bedrooms and I was thinking that I wouldn't mind a bit of that. I have a large kitchen/dining/living room with a wood/coal burner in it. This room is 8m x 5m and is at the side of the house and is single storey.
What I'd like help with is sizing a fan/hosing to move the warm air from the kichen to two of the bedrooms upstairs. I should have no problem routing the hosing.

Any help/tips greatly appreciated

I was looking at a friends rural cottage in Brittany and suggesting
they do this by changing the bedroom (it's a single bedroom cottage)
into a galleried bedroom, immediately above the wooodburner.

If one of the bedrooms to be heated is directly above the kitchen, then
I'd suggest floor vents on the appropriate side of the room (as many as
possible, passive, no fans). For getting the warm air from room to room
on the same floor, vents - bigger the better (and least number of
bends) - then you only need slow moving/quiet fans.

There may be building control issues here, due to the possibility of
smoke/fumes spilling from the stove (and any other heating appliances)
rather than going up the chimney/flue - due to the pressure differences
introduced by the fans.



Fatboise wrote:
Hi,
I was watching that program on BBC2 "It's not easy been green" and I
saw that they piped the warm air from the kitchen where the wood burner
is, up stairs to the bedrooms and I was thinking that I wouldn't mind a
bit of that. I have a large kitchen/dining/living room with a wood/coal
burner in it. This room is 8m x 5m and is at the side of the house and
is single storey.
What I'd like help with is sizing a fan/hosing to move the warm air
from the kichen to two of the bedrooms upstairs. I should have no
problem routing the hosing.

Any help/tips greatly appreciated


--
Fatboise

"Fatboise" wrote

What I'd like help with is sizing a fan/hosing to move the warm air
from the kichen to two of the bedrooms upstairs. I should have no
problem routing the hosing.

Look at Vent-Axia web site.
They have their "system calculator" document which gives info on duct and
fan sizes etc.
One thing to be aware of is the huge reduction in performance you will get
using concertina-type hose rather than smooth duct.
It may be far easier to route, but, size for size, it adds far more
resistance to air flow.

Phil

Look at Vent-Axia web site.
They have their "system calculator" document which gives info on duct and
fan sizes etc.
One thing to be aware of is the huge reduction in performance you will get
using concertina-type hose rather than smooth duct.
It may be far easier to route, but, size for size, it adds far more
resistance to air flow.

Phil [/quote]


Phil,
Thanks for the advice about the ducting. I had a look at the Vent-Axia website and it's just what I'm looking for don't know why I didn't find this when googling???

On Tue, 20 Jun 2006 16:39:19 +0100, Fatboise
wrote:


Look at Vent-Axia web site.
They have their "system calculator" document which gives info on duct
and
fan sizes etc.
One thing to be aware of is the huge reduction in performance you will
get
using concertina-type hose rather than smooth duct.
It may be far easier to route, but, size for size, it adds far more
resistance to air flow.

Phil


Phil,
Thanks for the advice about the ducting. I had a look at the
Vent-Axia website and it's just what I'm looking for don't know why I
didn't find this when googling???
Also remember if you want quiet operation choose a larger fan and run
it slower.

Robert
Robert

Fatboise wrote:
Hi,
I was watching that program on BBC2 "It's not easy been green" and I
saw that they piped the warm air from the kitchen where the wood burner
is, up stairs to the bedrooms and I was thinking that I wouldn't mind a
bit of that.

I thought they'd used a heat recovery unit with a cross-flow plate heat
exchanger ( but I wasn't paying much attention). Their intended use is
to pre-heat supply air from outside with an extracted air stream. The
air from the kitchen would usually be moisture-laden and exporting it
to elsewhere in the house would not be a good idea. If it's cooker
extract, then trying to recover heat from it would also not be a good
idea too. I think they'd do better with a air heater coil supplied with
LTHW from the heating system. The one they used seem to have electric
heaters which would undermine the green intent. I'm sure they know what
they're doing. ;-)

Both air streams entering the PHX should be filtered and a significant
part of the system resistance will be internal to the air handler, from
the filters & the PHX. The recovered heat would be a nuisance in
summer, unless you have a ducted by-pass around the heat recovery
device(s).

Aidan wrote:

I thought they'd used a heat recovery unit with a cross-flow plate heat
exchanger ( but I wasn't paying much attention). Their intended use is
to pre-heat supply air from outside with an extracted air stream.

And the heat transfer depends on the temperature difference.

If used to heat re-cycled (warm) room air with an extract air stream,
the efficiency will drop sharply, to the extent where the payback
achieved by the device (heat recovered v power consumed by the fans)
becomes dubious. Efficiency will be highest with cold incoming air.

Aidan, Thanks for your inputs. I looked at the vent-axia site and saw that they supply the heat recovery units which I had looked into somewhat when I thought of this project. The thing with my house is I have a solid fuel "pot belly" stove in the Kitchen/living room which is used during the winter. What I was planning was using the fan to move the heat to the bedroom late in the evening just before we go to bed so the remaining heat fromt he stove isn't lost in the Kitchen/living room when there is nobody there. At this stage of the evening there should be no cooking moisture or smells left in the room and if there is some late cooking I can put up with that the few times that it happens. The fan would be on for 1 hour at the most so I thought it wouldn't be worthwhile investing in the heat exchanger unit.

Fatboise wrote:
Aidan Wrote:
Aidan wrote:


And the heat transfer depends on the temperature difference.

If used to heat re-cycled (warm) room air with an extract air stream,
the efficiency will drop sharply, to the extent where the payback
achieved by the device (heat recovered v power consumed by the fans)
becomes dubious. Efficiency will be highest with cold incoming air.

Aidan, Thanks for your inputs. I looked at the vent-axia site and saw
that they supply the heat recovery units which I had looked into
somewhat when I thought of this project. The thing with my house is I
have a solid fuel "pot belly" stove in the Kitchen/living room which is
used during the winter. What I was planning was using the fan to move
the heat to the bedroom late in the evening just before we go to bed so
the remaining heat fromt he stove isn't lost in the Kitchen/living room
when there is nobody there. At this stage of the evening there should
be no cooking moisture or smells left in the room and if there is some
late cooking I can put up with that the few times that it happens. The
fan would be on for 1 hour at the most so I thought it wouldn't be
worthwhile investing in the heat exchanger unit.


--
Fatboise

Have same plan. Intend to blow the air from living room into the
ensuite shower cubicle in the bedroom. Whats best for duct - grey
rainwater goods or what?

cheers
Jacob

Have same plan. Intend to blow the air from living room into the
ensuite shower cubicle in the bedroom. Whats best for duct - grey
rainwater goods or what?

cheers
Jacob


http://www.bes.ltd.uk/products/180.asp do some lightweight duct 100 and 125
dia IIRC
I used the 100 recently for a toilet fan duct through loft space.

Phil