Moving 'spare' heat via room to room vents

[Niall]

Issue. We have installed a (possibly oversized) log burner in the 'drawing room' in our 1820 solid walled property and now I'm wondering if I can vent some spare heat into other rooms? Currently running it makes the living room nice and hot quickly but the value to the rest of the house is low. It's needed quite a bit from Sept/Oct as the house is drafty and we're in low hills S of Edinburgh. There is a fire place in every room but we don't need to have multiple log burners, when this is the only room we use after dinner.

Concept. See my scribbles below but I've got this idea of a vent above the door (where the air flows orange arrow) coming up into the join in the matching partition wall above. This offers three walls to vent out from into master, spare and upstairs landing, meaning a lot of 'spread' for minimal ducting. Crucially it would heat the two bed rooms that might be used after the livening room.

There's a range of 'Hit and Miss' style vents to choose from like the below kinda thing, and I thought I could have a bit of modern ducting in the wall and between the floor boards.



Wider Context. Going forward, we're about to underfloor heat the other 2/3 of the ground floor inc the hall, and will eventually insulate below the foor of this room and the 'study'. This will then be hooked up to a heat pump in time, shout out to Heat geeks for great advice on that. This will mean the wood burner is then used only for the coldest days to take the load off the heat pump and all the more reason to spread the heat around.

 

[Cubist]

This old place is exclusively heated using two log burners. A small 8kW stove sited in the lounge and a 14kW big brother in the next room, our dining hall, that, in addition to general point heating also drives our wet CH system. At this time of year with temperatures starting to fall but hovering around 15C for the most part the bigger stove remains unused and the small one is usually only lit in the evenings when it starts to get a little nippy. It quite admirably can heat the lounge to around 20C quite rapidly and, with the addition of a couple of logs during the course of the evening, can maintain that temperature for around 5-6 hours. I should point out here though that we have no doors on the ground floor between the lounge and dining hall and the route between them includes a stairwell that provides direct access to the first floor bedrooms. Whilst the bedrooms are equipped with doors these are seldom closed during the evenings and only doing the normal bedtime hours. As a consequence the convection currents created by the stove shares the heat it generates with almost all the other rooms in the house and in the late evenings the lounge can still become uncomfortably warm if I continue to stoke the fire.

Could I suggest that you consider just leaving the doors open to test whether the stove you have could make an appreciable difference to the warmth of the other rooms before going to the lengths of installing vents and ducting in what I think may be a vain effort to direct any excess heat.

 

[Zebra]

I have an open stairwell to the bedroom upstairs, directly above the living room which contains the fire. There are no doors in between. Both the bedroom and living room are small (3m x 4m) and the living room has a low ceiling. The bedroom is still cold after an evening with the fire lit, even when the living room directly below is toasty.
This whole "heat rises" thing, I think science may have got it wrong.....

 

[Cubist]

Ah, I forgot. This place has a thatched roof and a thoroughly insulated but cramped loft so perhaps the house is trifle more energy efficient than some?

I also forget that I'm one of those people whose personal body temperature typically runs hotter than most..... which also explains some other things too.

 

[paulc]

Also have a stove that is way overpowered for the size of the room. Only need 2-2.5kW, but the stove is rated at 7kW. Consequently, it is not that difficult to get above toasty. Keeping all the doors open allows for warm air to circulate to the rest of the house. The bedroom above the room where the stove is also benefits from heat being radiated from the chimney. Did toy with the idea of ducting and fans to direct some of the heat to other rooms, but that is far as it ever got.

 

[Mulder]

I am sceptical of this will really deliver much heat due to the small size of the vents and their position away from the stove.

I have considered this too, but for heating the bedroom directly above the stove. I suspect my design may have better chance of success as the vent would be almost directly above the stove and would rely on natural convection upwards.

I'm no expert so may be completely wrong here, but it's my understanding that heat doesn't naturally rise, it's the cold, denser air that sinks, which then pushes the warm air up. So I would imagine what you want is a way to cycle the cold air from the other rooms, into the hot room and replace it with warm air. Maybe some matching vents at floor level, ideally on the opposite side of the room, would setup some sort of convection flow.

 

[eezageeza]

I've tried a hit and miss type vent in the ceiling, but found it to have very little effect. The upstairs landing (where the vent emerges) is marginally warmer, and the room where we have the log buner doesn't tend to get as overpoweringly hot as it used to before, but overall I think it wasn't worth the effort of installing it!

An alternative to consider might be the door fans that seem popular in the States :

Robot or human?

but I haven't got around to trying one yet - they seem to be readily available in the US, but not over here.

PS I have no idea why the link says 'robot or human'! But it does work!