Log drying kiln idea

[sjs5060]

Just looking for folks opinions on what may or may not be a daft idea.

 

lets say I have a insulated container about 10 feet long and a supply of waste wood.

if I where to install a large log burner at one end, mount a heat store above it, probably a 6'x2' piece of 2" thick steel then bag several thermoelectric fans on top to create some airflow will it dry logs?

 

been thinking about this past couple of days and in my head it may work but fact is there's lads on here with far more experience and knowledge on these things so I love your thoughts.

 

thanks, Ste 

[sandspider]

I'm by no means an expert, but I think you'll just be blowing warm, moist air around your logs. If you don't figure out a way to release moisture (without losing heat) I'm not sure that will help much?

[richardwale]

I want to do exactly the same kind of thing...interested to hear any success stories

[bankhouse builder]

I again have thought about this idea I would run the flue down the length of the container to get the heat out before it is lost and I was going to install a dehumidifier the large type you get on sites with the outlet piped to the outside . I think it would work well as long as you have enough air movement.

 

[Squaredy]

1 hour ago, bankhouse builder said:

I again have thought about this idea I would run the flue down the length of the container to get the heat out before it is lost and I was going to install a dehumidifier the large type you get on sites with the outlet piped to the outside . I think it would work well as long as you have enough air movement.

 

A dehumidifier will work but for any decent amount of logs it will need to be very large and therefore cost a fortune to run.  

 

A poly tunnel is hard to beat. Ends partly open.  That way you get lots of free heat.  I would strongly suggest trying to use solar energy. If you google solar kiln you will find loads of good info.

[sjs5060]

Thanks for the replies. Squaredy I'm not discounting a poly tunnel at some stage but it's not possible at this stage.

A good mate of mine built a kiln with an insulated container, hole in the side, poked a space heater in and that was it. He leaves the door slightly ajar and you can see water running out of it, it's also a shit load faster than his glen farrow kiln. But obviously cost a lot in leccy/paraffin.

What I'm asking is what's the difference in the space heater and log burner? If the container gets hot enough surely the water comes out of the logs? As I say I'm not an expert on the science of it all but don't want to waste time/money if it won't work.

 

ste

[Squaredy]

2 hours ago, sjs5060 said:

Thanks for the replies. Squaredy I'm not discounting a poly tunnel at some stage but it's not possible at this stage.

A good mate of mine built a kiln with an insulated container, hole in the side, poked a space heater in and that was it. He leaves the door slightly ajar and you can see water running out of it, it's also a shit load faster than his glen farrow kiln. But obviously cost a lot in leccy/paraffin.

What I'm asking is what's the difference in the space heater and log burner? If the container gets hot enough surely the water comes out of the logs? As I say I'm not an expert on the science of it all but don't want to waste time/money if it won't work.

 

ste

There are two main types of kiln: heat vent and dehumidifier.  Both are costly to run.  The former loses a lot of heat so only works if you have cheap heat.  The latter loses less heat but uses loads of electricity which is very expensive.  

 

It makes a huge difference what stock you intend to dry. If it is already well air dried a small kiln may work well.  If it is very freshly cut then unless it is all ash it may cost more to kiln than it is worth.  Ash is the exception because it is always fairly dry even when just felled.

Edited October 4, 2018 by Squaredy

[andy cobb]

Instead of the big lump of steel as a heat sink could you not use the heat bricks from old storage heaters?

[bankhouse builder]

I agree a poly tunnel is a good way I air dry mine which is easy as we are nearly a 1000ft up and the wind is always blowing it would be best I think to air dry the logs and finish them in the kiln . My problem is that we can get low cloud and everything just gets wet so thought a small kiln to just finish 10m3 at a time.

 

[woodrascal]

You really need to make sure there's plenty of ventilation to remove the damp, warm air. You'd be better off sacrificing a lower temp inside the container for a stronger air flow to help get the logs dry.

Andy's idea of replacing the sheet of steel near the burner with storage heater bricks or other thermal mass would work well.