Deleted

Doc_N

badger09 said:

Doc_N said:

Sounds counterintuitive, but actually very sensible, particularly when you've got a woodburner pushing out large volumes of heat in one place.

Never considered it, but in the event of power cuts this winter when we'd have to use the woodburner alone I'll certainly give it some serious thought.

Thanks!

But ‘in the event of power cuts’ how will you power the fan?
Or have I misunderstood? 

A very good point. I’m working on the basis though that there will be rota cuts, as planned, and that the power will be there for long enough to move the heat. We have some very powerful fans. There are also some pretty good battery units with large rechargeable batteries.

Effician

Doc_N said:

badger09 said:

Doc_N said:

Sounds counterintuitive, but actually very sensible, particularly when you've got a woodburner pushing out large volumes of heat in one place.

Never considered it, but in the event of power cuts this winter when we'd have to use the woodburner alone I'll certainly give it some serious thought.

Thanks!

But ‘in the event of power cuts’ how will you power the fan?
Or have I misunderstood? 

A very good point. I’m working on the basis though that there will be rota cuts, as planned, and that the power will be there for long enough to move the heat. We have some very powerful fans. There are also some pretty good battery units with large rechargeable batteries.

Old car & leisure batteries + inverter for us, enough to keep the router/ tv & fans going for a while.

chris_n

@Deleted_User has a solar powered back up battery system. 

worlestone

We have Economy 7 and several old (40+ years) storage heaters and a 5kw Charnwood woodburner in a 4 bed house, no gas in the village.  We did something foolish when we moved in, which was to block up the air vents from the back of the open fire which circulated air, using a cold air fan assisted feed in from outside, using a heat exchanger at the back of the fire to mor=ve warm air into the dining room/kitchen and hallway. Replaced all of this with a woodburner, seemed a good idea at the time, but moving warm air is a good idea.  The fireplace was a Swedish design/made and ahead of it's time, such a goo idea, but we didn't realise what we had

We have two doors from the lounge, into dining room/kitchen and hallway, so I'm going to experiment with circulating warm air.  We do to an extent at the moment, by having both doors open, but no active air circulation.  What fun

Effician

Deleted_User said:

Effician said:

Deleted_User said:
a) push cold air into the warm room rather than warm air into the cold room.
b) don't let an airflow get established - start your fans up as soon as you light the fire.
c) Have the fan  blowing the cold air into the warm  room at floor level
d) have any fans blowing hot air into cold areas high up

The thought that airflow will become established is an odd idea to me as my approach is to mix the air as much as possible with as little air airflow as possible ( low fan speeds & large dia blades).

Either push/suck cold air to the ceiling or hot air to the floor, the more even the air temp the better the heat take up of the fabric of the house & lower drop off in room temps overnight.

Essentially, it's about the wisdom of radiators under windows. This argues that it is still a good idea as you want your heat source in the coldest spot - under the window the heat will rise creating a curtain of warm air that keeps cold out. I've also seen this disputed.

It doesn't keep the cold out , it warms it as it comes in therefore reducing cold draughts. 

Cold & warm air will stratify unless you mix it , by putting cold above hot

On the point of draughts it may be worth noting that  DEFRA spec stoves will always vent air up the flue even when unused due to the secondary air intake not being allowed to fully close, in a room fed stove this means air being drawn from the room & up the flue even when the stove is shut down, for a direct air stove at this time of year can drop the stove temp close to outside air temp when not in use, almost like having a fridge door open.

Edited to take out wrong statement of vice versa

Doc_N

Effician said:

Doc_N said:

badger09 said:

Doc_N said:

Sounds counterintuitive, but actually very sensible, particularly when you've got a woodburner pushing out large volumes of heat in one place.

Never considered it, but in the event of power cuts this winter when we'd have to use the woodburner alone I'll certainly give it some serious thought.

Thanks!

But ‘in the event of power cuts’ how will you power the fan?
Or have I misunderstood? 

A very good point. I’m working on the basis though that there will be rota cuts, as planned, and that the power will be there for long enough to move the heat. We have some very powerful fans. There are also some pretty good battery units with large rechargeable batteries.

Old car & leisure batteries + inverter for us, enough to keep the router/ tv & fans going for a while.

Good point - I keep a couple of leisure batteries charged all the time, plus an inverter, but I hadn't thought of using them for fans!

Effician

Deleted_User said:

Effician said:

Deleted_User said:

Effician said:

Deleted_User said:
a) push cold air into the warm room rather than warm air into the cold room.
b) don't let an airflow get established - start your fans up as soon as you light the fire.
c) Have the fan  blowing the cold air into the warm  room at floor level
d) have any fans blowing hot air into cold areas high up

The thought that airflow will become established is an odd idea to me as my approach is to mix the air as much as possible with as little air airflow as possible ( low fan speeds & large dia blades).

Either push/suck cold air to the ceiling or hot air to the floor, the more even the air temp the better the heat take up of the fabric of the house & lower drop off in room temps overnight.

Essentially, it's about the wisdom of radiators under windows. This argues that it is still a good idea as you want your heat source in the coldest spot - under the window the heat will rise creating a curtain of warm air that keeps cold out. I've also seen this disputed.

It doesn't keep the cold out , it warms it as it comes in therefore reducing cold draughts. 

Cold & warm air will stratify unless you mix it , either by putting cold above hot or vice versa.

On the point of draughts it may be worth noting that  DEFRA spec stoves will always vent air up the flue even when unused due to the secondary air intake not being allowed to fully close, in a room fed stove this means air being drawn from the room & up the flue even when the stove is shut down, for a direct air stove at this time of year can drop the stove temp close to outside air temp when not in use, almost like having a fridge door open.

And in  the articles I'm referring to earlier but can't find right now, it shows the ideal of a cycle where the warm air rises from the radiator, travels across the ceiling then as it reaches the other side of the room it drops (because it's cooled) and the cool air travels across the floor and back to the radiator.

Convection currents, yes the air is heated by the stove/radiator etc & rises to the ceiling then falls as it cools somewhere on the other side of the room, it could be called passive airflow i suppose, I don't want that to happen at all which is why i use fans, i push the warm/cold air where i want it to go.

Effician

Deleted_User said:

Effician said:

Deleted_User said:

Effician said:

Deleted_User said:

Effician said:

Deleted_User said:
a) push cold air into the warm room rather than warm air into the cold room.
b) don't let an airflow get established - start your fans up as soon as you light the fire.
c) Have the fan  blowing the cold air into the warm  room at floor level
d) have any fans blowing hot air into cold areas high up

The thought that airflow will become established is an odd idea to me as my approach is to mix the air as much as possible with as little air airflow as possible ( low fan speeds & large dia blades).

Either push/suck cold air to the ceiling or hot air to the floor, the more even the air temp the better the heat take up of the fabric of the house & lower drop off in room temps overnight.

Essentially, it's about the wisdom of radiators under windows. This argues that it is still a good idea as you want your heat source in the coldest spot - under the window the heat will rise creating a curtain of warm air that keeps cold out. I've also seen this disputed.

It doesn't keep the cold out , it warms it as it comes in therefore reducing cold draughts. 

Cold & warm air will stratify unless you mix it , either by putting cold above hot or vice versa.

On the point of draughts it may be worth noting that  DEFRA spec stoves will always vent air up the flue even when unused due to the secondary air intake not being allowed to fully close, in a room fed stove this means air being drawn from the room & up the flue even when the stove is shut down, for a direct air stove at this time of year can drop the stove temp close to outside air temp when not in use, almost like having a fridge door open.

And in  the articles I'm referring to earlier but can't find right now, it shows the ideal of a cycle where the warm air rises from the radiator, travels across the ceiling then as it reaches the other side of the room it drops (because it's cooled) and the cool air travels across the floor and back to the radiator.

Convection currents, yes the air is heated by the stove/radiator etc & rises to the ceiling then falls as it cools somewhere on the other side of the room, it could be called passive airflow i suppose, I don't want that to happen at all which is why i use fans, i push the warm/cold air where i want it to go.

So taking an example of a single room - those air flows can create cold draughts at your feet. I'm guessing that's your reasoning for mixing the air? So you have a constant temperature of air in the room and the stove just keeps raising that temp? Makes sense.

BUT someone stated earlier that they had trouble getting the fans to move the air. And that was my experience too. Until you get your entire house (or the parts you want to heat) to a constant temperature you will have cold air rushing into the warm rooms (at ground level) and hot air rushing out (at ceiling level). The air will set up it's own currents based upon the structure of your house and positioning of stove. And that might not be the optimal air flow for pushing warm air around the whole house.

By setting up fans to influence the way that airflow develops, I think (in my experience thus far) you can speed up the process of initially getting the warm air into the cold rooms at the other side of the house. And once that airflow is established you can turn off the fans and it takes care of itself (or so it seems thus far).  

We don't get cold air rushing anywhere, we have sealed up all draughts inc trickle vents & made drop down cover for hob fan vent, the direct air stove means we have no need for a vent hole in the wall & have 18yr old DG throughout, we're not hermetically sealed as it's a 150yr old mid terraced property ( not very heat generous neighbours)so no fear of being suffocated, just no discernible draughts.

We rarely have less than 4 fans running during the daytime & often 6 or 8 when the stoves running harder on very cold days , it's not a case of switching off a fan when the room becomes warm enough we just keep them going .

Effician

Deleted_User said:

Effician said:

Deleted_User said:

Effician said:

Deleted_User said:

Effician said:

Deleted_User said:

Effician said:

Deleted_User said:
a) push cold air into the warm room rather than warm air into the cold room.
b) don't let an airflow get established - start your fans up as soon as you light the fire.
c) Have the fan  blowing the cold air into the warm  room at floor level
d) have any fans blowing hot air into cold areas high up

The thought that airflow will become established is an odd idea to me as my approach is to mix the air as much as possible with as little air airflow as possible ( low fan speeds & large dia blades).

Either push/suck cold air to the ceiling or hot air to the floor, the more even the air temp the better the heat take up of the fabric of the house & lower drop off in room temps overnight.

Essentially, it's about the wisdom of radiators under windows. This argues that it is still a good idea as you want your heat source in the coldest spot - under the window the heat will rise creating a curtain of warm air that keeps cold out. I've also seen this disputed.

It doesn't keep the cold out , it warms it as it comes in therefore reducing cold draughts. 

Cold & warm air will stratify unless you mix it , either by putting cold above hot or vice versa.

On the point of draughts it may be worth noting that  DEFRA spec stoves will always vent air up the flue even when unused due to the secondary air intake not being allowed to fully close, in a room fed stove this means air being drawn from the room & up the flue even when the stove is shut down, for a direct air stove at this time of year can drop the stove temp close to outside air temp when not in use, almost like having a fridge door open.

And in  the articles I'm referring to earlier but can't find right now, it shows the ideal of a cycle where the warm air rises from the radiator, travels across the ceiling then as it reaches the other side of the room it drops (because it's cooled) and the cool air travels across the floor and back to the radiator.

Convection currents, yes the air is heated by the stove/radiator etc & rises to the ceiling then falls as it cools somewhere on the other side of the room, it could be called passive airflow i suppose, I don't want that to happen at all which is why i use fans, i push the warm/cold air where i want it to go.

So taking an example of a single room - those air flows can create cold draughts at your feet. I'm guessing that's your reasoning for mixing the air? So you have a constant temperature of air in the room and the stove just keeps raising that temp? Makes sense.

BUT someone stated earlier that they had trouble getting the fans to move the air. And that was my experience too. Until you get your entire house (or the parts you want to heat) to a constant temperature you will have cold air rushing into the warm rooms (at ground level) and hot air rushing out (at ceiling level). The air will set up it's own currents based upon the structure of your house and positioning of stove. And that might not be the optimal air flow for pushing warm air around the whole house.

By setting up fans to influence the way that airflow develops, I think (in my experience thus far) you can speed up the process of initially getting the warm air into the cold rooms at the other side of the house. And once that airflow is established you can turn off the fans and it takes care of itself (or so it seems thus far).  

We don't get cold air rushing anywhere, we have sealed up all draughts inc trickle vents & made drop down cover for hob fan vent, the direct air stove means we have no need for a vent hole in the wall & have 18yr old DG throughout, we're not hermetically sealed as it's a 150yr old mid terraced property ( not very heat generous neighbours)so no fear of being suffocated, just no discernible draughts.

We rarely have less than 4 fans running during the daytime & often 6 or 8 when the stoves running harder on very cold days , it's not a case of switching off a fan when the room becomes warm enough we just keep them going .

I don't mean cold from outside.

Unless you keep your house heated to a constant temp 24/7, when you light your woodburner the heat will build up in the room that the woodburner is in first. As that happens, warm air will start to move into other rooms and that will cause cold air from those rooms to come rushing in.

Neither did i.

We don't experience the effect you describe at all because the air is always being mixed & circulated.

[Deleted User]

Having failed to boil a kettle on my log burner I've now turned my attention to improving the air circulation with fans.

I already have a stove top fan which does a good job of evening out the temperature in the living room.

The master bedroom and living room are opposite corners of the bungalow and separated by a hallway. All doors are open. Current temperatures are living room 21.3 hallway 21.0 bedroom 17.2.

I've just stood a desk fan on the floor in the bedroom door blowing the cold air from the bedroom into the hallway. Lets see what effect it has