What makes stoves so efficient?

[AHPP]

2 hours ago, openspaceman said:

the difference between power and energy.

What is it?

 

[neiln]

power is a rate of doing work, ie energy per unit of time.  Watts.  Watt = Joule per second.  

energy is Joule, or power multiplied by a time period, kWHr.

[Woodworks]

17 hours ago, slim reaper said:

Have you got any info on that system, I am in the near future going to render some stone walls but was going to use lime with cork pellets incorporated. 

Used to be talked about quite a bit on the Green Building Forum. http://www.greenbuildingforum.co.uk/newforum/search.php?PostBackAction=Search&Keywords=hempcrete&Type=Topics&btnSubmit=Search

[billpierce]

Some good reading here. And there is another good one with designs of frontier type DIY woodstoves and ovens from folded tim/ barrels etc.

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.fastonline.org/CD3WD_40/JF/425/20-461%2520-%2520Wood%2520Stoves%2520-%2520Ole%2520Wik%25202.pdf&ved=2ahUKEwjLm-DK69vfAhWKyIUKHWjMBbgQFjAbegQIARAB&usg=AOvVaw2ae0wVUiXVNaiQ2AnyAXRs&cshid=1546869962294

[Steven P]

Thanks for the info

 

So for efficiency I need (and I think in the order of importance):

- Limit the air going up the chimney, use a door then

- Insulated fire box, hotter fire = more efficient

- Make sure the flame can burn fully before its extinguished and goes up the chimney.  In a stove this is using a baffle plate, I might be wrong but isn;t this so they can increase the flame length and make the stove shorter? In a traditional fire the flame fully burns out but part way up the chimney first.

- Air gap around the stove lets heat get out by convection currents and not just by radiated heat

 

Is that about it?

 

So thinking to my small upstairs fire, I could get a local blacksmith to make a suitable door on a hinge (complete with vents and clips to hold a glass window in), bolt that on and the open fire might double its efficiency? A door would be god because it can be  kept closed and stop draughts up the chimney when not in use? After that I would want to get a builder in to open up the fire place to install a stove

 

[Big J]

4 minutes ago, Steven P said:

 

 

So thinking to my small upstairs fire, I could get a local blacksmith to make a suitable door on a hinge (complete with vents and clips to hold a glass window in), bolt that on and the open fire might double its efficiency? A door would be god because it can be  kept closed and stop draughts up the chimney when not in use? After that I would want to get a builder in to open up the fire place to install a stove

 

I would advise caution. The door would have to have a very tight fit to be functional. With all the stoves I've had, once up to temperature, the amount of air they require is minute. A badly sealed door on an open fire would most likely cause overheating with intense, directed air flow.

 

Best just to take the open fire out and replace with a stove.

[Stubby]

Just get the smallest Burley stove . It has a well insulated fire box with a single double glazed door giving high efficiency rating

[benedmonds]

If space is an issue get an inset stove. 

https://goo.gl/images/NsGBpj

We have a narrow lounge and found this took up the least space. 

[slim reaper]

You may find that fitting a free standing stove and compliant hearth eats quite bit of space out of a room space..inset stoves as suggested are neat , Stovax Riva belt out some heat for their size 

[Alycidon]

The installation of a register plate into the base of the chimney to prevent heat loss up the chimney is the single most important reason why a stove provides far more heat into the room compared to an open fire.    I looked at two earlier this week due to poor heat outputs., they had no register plates and flue pipes around 2mm away from oak lintels that were badly charred, builder install in 2005, am amazed the lintels have not caught fire.  Thus all the heat generated goes straight up the chimneys.

 

A