stove size and using an inline fan

[slim reaper]

I would look to go bigger especially as you dont intend firing for long periods so would need quicker warm up ,  then throttle it back by combination of air vent and   fuel load if its on for longer . I have a 5kw  stove that can put out 8 in a 70m3, 6.2m long room, your room  is double that size .  Mine takes around 4 hours to get the temperature up to 18 degrees the opposite end to the fire so will be fitting one with more oomph.

 

 

Edited December 28, 2021 by slim reaper

[Stere]

https://ls-kamna.s12.cdn-upgates.com/n/n5f0fd91bcd53b-letak-turbo.pdf

 

Sounds abit like this hot air duct system

 

 

A small 15w electric desk fan  above a stove works quite well better than a thermo electric one as pushes more air volume.

Edited December 28, 2021 by Stere

[openspaceman]

35 minutes ago, Stere said:

https://ls-kamna.s12.cdn-upgates.com/n/n5f0fd91bcd53b-letak-turbo.pdf

 

Sounds abit like this hot air duct system

 

 

A small 15w electric desk fan  above a stove works quite well better than a thermo electric one as pushes more air volume.

It would because those TEG ones are less than 1W.

 

The inline centrifugal fan I use is 6" 150W but I use it on the lowest of 4 settings. I  had it previously as it powered my 100kW vortex burner and saved buying new.

 

Similar to this

 

Vent Axia 150mm 6" In-Line Centrifugal Duct Fan (SDX150) | CEF

WWW.CEF.CO.UK

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Motor Insulation Class B protected to IP44

 

[openspaceman]

10 hours ago, drinksloe said:

 

Would a stove 2.5kw more than reccommended make a room 50m2 ( or 150m3) which is a big room with 4 big windows too hot? Even if only on for 3 to 4 hours or so a day?

To me it doesn't seem a massive amount more in such a big room

 

I cannot see that being a problem, even if it were you could reduce the fire size by putting a couple of firebricks on the inside of the combustion chamber.

 

In my case because all the hot air coming out of the convection ducts gets routed into the other room, if the fan is on, the stove doesn't put so much heat into this room I use as an office.

10 hours ago, drinksloe said:

 

 

My 2nd question is similar to wot u have done above Openspace, i was planning on having an inlet vent in the ceiling above log burner connected to a decent sized inline fan to suck the hot air above the log burner and blow it to the far side of the house throu insulated ducting in the loft.

 

My arrangement passes air at 40C into the other room via a duct constructed of plasterboard and sealed.  My only worry would be if the air were any hotter than that. I have a thermometer at the outlet and have never seen a higher temperature. Mine also vents into the other room at floor level.

[neiln]

It's usually more effective to blow the cold dense air toward the stove and displace the got air than the other way around.

[drinksloe]

Cheers folks

I think i'll go with the bigger stove then.

 

Aye open thats exactly the type of fans i was looking at coupled with that insulated felxi ducting.

 

I take it this system would work better if the outlet vents are at floor level rather than ceiling level so the hot air doesn't just hang about at the top.

 

Not expecting great lots of heat from it but if i can get a wee bit extra up far end of the house and take the excess away from the log burner area its just a win win really

 

There is a drying cupboad being put in which i was hoping to blow warm air into, only 1.5 x 2.5m but it could make a massive differnce for that, as in the spring/summer/autumn time if heating off/low, i think  the UFH might be too slow to respond to dry ur wet cutting gear and getting it dry for next morning.

We'll soon find out anyway 1 way or other, can always stick an electric in if i really need to for odd occasions for such a small space

Edited December 29, 2021 by drinksloe

[drinksloe]

1 hour ago, neiln said:

It's usually more effective to blow the cold dense air toward the stove and displace the got air than the other way around.

 

Every day is a school day, neve rheard that 1 before.

 

So if i had an electric fan at ground level blowing air toward the stove it would maximise the heat??

Trying to get a bit of flow going

[neiln]

Yes. It's easier/more effective to blow cold dense air around, so put a fan in the cold spot and bliss the cold air at the stove, the warm air is displaced over it and you'll set up s circulation

[openspaceman]

1 hour ago, neiln said:

It's usually more effective to blow the cold dense air toward the stove and displace the got air than the other way around.

That's right  in terms of fan power requirement because the power required to move air is directly proportional to the volume of air moved against the resistance. The volume of cold air has more mass than the same volume of heated air but to benefit from this the cold air would need to be ducted all the way around the stove and into the duct serving the next room which, in my case at least, is impractical and the electrical power required is a small fraction of the energy delivered by the fan as warm air.

43 minutes ago, drinksloe said:

 

Aye open thats exactly the type of fans i was looking at coupled with that insulated felxi ducting.

Fine as long as the warm air is not allowed to get too hot.

43 minutes ago, drinksloe said:

 

I take it this system would work better if the outlet vents are at floor level rather than ceiling level so the hot air doesn't just hang about at the top.

Yes and there is an effect, the Coanda effect, that shows if you discharge it horizontally from a flat nozzle it will hug the floor for some distance before it starts rising, not something I have tried yet.

43 minutes ago, drinksloe said:

 

Not expecting great lots of heat from it but if i can get a wee bit extra up far end of the house and take the excess away from the log burner area its just a win win really

Yes and with mine I think it delivers the same heat as a 6 by 3 double radiator which we used previously to heat the room.

43 minutes ago, drinksloe said:

 

There is a drying cupboad being put in which i was hoping to blow warm air into, only 1.5 x 2.5m but it could make a massive differnce for that, as in the spring/summer/autumn time if heating off/low, i think  the UFH might be too slow to respond to dry ur wet cutting gear and getting it dry for next morning.

Do you have a dehumidifier in the drying cupboard?

[Steven P]

So being similarly tight... based on what I use, 80m3 is going to last a while so well worth making the most of it. It would be a different answer if you said 20m3, or 3 or 4 years worth,. Fire in the morning and then fire in the evening - morning fire to help out the other heating systems - my view that a smaller temperature variation is the best in the house, whether it is is between 19 and 22 deg C or 10 to 15 deg C, however you like it... but letting the temperature drop while you are out is the most efficient and cheapest though you suffer an hour or so of cool when you get in again.

 

Stove.... go bigger if you have space and the regulation air supply (air supply plumbed direct to the stove is a good option). Stove top fan to get some air circulation, maybe 2 if you want to be flash.

 

The next step I would go for is insulation and some insulation... the powers that be will insist on a minimum but while you are doing it be worth while getting the best you can afford, or the thickest layer of the cheapest that your space allows for. If the floorboards are up... ideal time to do under them too (else you will end up crawling under the floor to upgrade later if you want to and cutting holes in your floor to do so). You probably know that. And windows, again, for the costs of any new windows you put in, the step up to extra insulated might be worth it.

 

Then a couple of cans of expanding foam or silicone sealer to seal all the gaps too (at a £5 each?)

 

Then look at the what to put in for the rest of the heating. In the next few years gas boilers are going to be going out, in 10 years whatever fancy systems are installed just now will be replaced with electric boilers. Would it be worthwhile putting in an emersion heater for hot water (or maybe an instant hot water for the kitchen and bathroom sinks, plus a tank for a bath) and do away with a boiler all together? Electric under floor heating.

 

Just to throw in an curved ball here too, one I might look into in the next few years is an air source heat pump.... but pumping out warm air and not hot water. Simpler and cheaper. Air source pump outside the house somewhere, and a duct into the house for the hot air to a simple wall unit? It might be that by ditching the LPG boiler (what £4k?) you might be able to install 2kW of solar panels? daytime heating if the sun comes out and a summer earner

 

Just a couple of thoughts anyway... big stove, insulation and consider electric heating + solar panels