Kiln Drying times for Firewood

[dan_the_man]

Hi All,

I have spent the past week or so reading with interest about kiln drying wood I am based in New Zealand and looking at setting up a 40' Refer with a DH unit. I would primarily use it for drying pine firewood but based on what i have read there is a possibility i could rent it out to some local mills in the off season. my questions are:

1, Does anyone have any experience with drying firewood in a kiln
2, What sort of drying times should I expect using a Nyle L200 in a 40' refer (fully loaded as per Nyle specs)
3, Could i install additional heating to speed up the drying proscess
4, should I move up to the L300 or L500 for shorter turnaround

Very Interested to hear your feedback.

Dan

[JustinW_NZ]

Yo bro, what ya know?  ;D

Where you based? (I'm in Nelson)

I've thought a little bit similar for firewood, but if your having to spend money on power to dry it I don't think pine firewood would be worth it (not in this area anyway)
Eucalypt yes but again that could just be this area.

I will be building a solar kiln and use a small DH setup soon I hope and was thinking if its not drying flooring I could fire in firewood perhaps?

Cheers
Justin

[dan_the_man]

How's it going Justin, I am based in Palmerston North. I know it seems bizarre to kiln dry firewood but we have extensive demand and it becomes a balance between housing it (real estate) or drying it eaither way we can pass the cost on to the end user.

It appears the we are becoming a country of consumers and there is a growing expectation that you can just pick up the phone in the middle of winter and get a load of perfectly dry firewood delivered within 24 hours. We all know that as this is not practical unless you have a large storage facility or a kiln. To me a kiln is a logical option it will enable me to supply to demand without a large capital investment.

[JustinW_NZ]

yes, I know the issue my brother in law was managing a firewood yard.

They luckily had a fair amount of storage but yes, your right about people waiting till the end of winter wanting dry wood!

The big thing about drying is the airflow, so with firewood, i'm not sure how you would "bin" the wood to get enough air through it, as stacking it nicely would just eat far to much time.
To me this is the crux of kilning firewood, get it moveable and small enough to get air through it (so it dries within a good timeframe) without burning lots of labour doing so.
Pine otherwise should dry down pretty quick even in the simplest setup I feel.
Again, I haven't tried this as i'm going to build a solar kiln for drying hardwood flooring, and was thinking about the secondary uses like drying firewood... (albeit not on a commercial scale)

Cheers
Justin

[Ianab]

Problem is the economics of it.

Will people pay enough premium for the dry wood to cover the cost of kiln drying it? Maybe on the bags of firewood sold in the servo. But that's for the folks that just want a fire for decoration.

Is there a local timber processor that runs a finger jointer operation. In that case they are feeding kiln dried pine into a big machine that cuts out ~20% of the wood (knots and defects) That wood goes into a bin and gets sold to a local firewood processor. Nice chunks of 6x1 etc, all kiln dry and chopped into firewood lengths. Ideal stuff.

Other mill just sells green slab wood by the truckload. Cheaper, but you need to stack it and dry it for a summer first. That needs forward planning.

No good answer, but kiln drying firewood just doesn't seem practical?

Ian

[Den Socling]

Is this an all Kiwi thread?  :D We have a kiln controller customer that kiln dries firewood that is distributed at grocery store, big box stores, etc. They are making money. Around here you need recorded proof that the wood was heated high enough to be sterile.

[CRThomas]

Hi All,

I have spent the past week or so reading with interest about kiln drying wood I am based in New Zealand and looking at setting up a 40' Refer with a DH unit. I would primarily use it for drying pine firewood but based on what i have read there is a possibility i could rent it out to some local mills in the off season. my questions are:

1, Does anyone have any experience with drying firewood in a kiln
2, What sort of drying times should I expect using a Nyle L200 in a 40' refer (fully loaded as per Nyle specs)
3, Could i install additional heating to speed up the drying proscess
4, should I move up to the L300 or L500 for shorter turnaround

Very Interested to hear your feedback.

Dan

Here we go The reason drying wood in the out side or air drying is you want your firewood down to about 15 percent your wood will not dry as long as the air percent is higher than your wood percent. I only kiln dry my wood but I only use Ash. In my kiln it will hold a cord but I only dry a rank or two at a time my dry time in my kiln is 24 hours I will have it down to 8 to 10 on the ends resplit a stick the middle will be 14 to 16 percent. I use NG and air flow in wet weather I turn on my dehy. thats my way that way I haul the logs in dump chunk them and let them lay. I had a shipping container set up and I got offer 8 times more than I had in it so it had to go. I built a kiln in the corner of my shop so I heat my shop also. I only sell bundled firewood. People buy my bundles as a starter wood around here most sold firewood is called dry at 40 to 60 percent last January in cold front we had I sold a 300 to 400 bundles a week at $5.00 a bundle. that cold spell made me a bunch of new customer. I am having to get with it all ready. people are wanting 5 to 10 bundles now in a 90 degree weather. I had to buy 2 semi loads of Ash logs. If you sell one rank of wet wood you might as well go out of business so many people are starting to burn wood for heat or as a helper in the fire place for looks or to break the chill till it warms up. I have find a kiln dry is the only way to go. I posted some place for a fellow the break down in cost to kiln dry wood  later

[dan_the_man]

Hi guys,
Thanks for the feed back, I have done a heap of research in the past week or so. Purchased some plans from Nyle for a DH kiln and been in touch with Hank at Nyle also and he also sent me some excellent information and pics. I can highly recommend Nyle if you need to build a kiln for milled timber. However, It appears that DH drying Firewood will be to slow and expensive so it looks like the comment from Hank will be the the way to go "For firewood you want brutally hot air and gobs of wind."

So the plan is purchases a 40' refer container (I can get one for around $4000 - $4500 delivered) make a few mods to accommodate a waist oil burner courtesy of youtube and some fans. Build some cages and add some tracks to the container and we should be in business.

I have missed the boat this season but it will be my next project ready for next season. I will keep you posted but if anyone has any ideas on expelling the moisture without loosing to much heat it would be appreciated.

[JustinW_NZ]

One thing I was thinking off for "free heat" was if you can put your container by a bank you could put some solar water panels in below it and thermosyphon the water around through a heat exchanger in the container, no pump needed then and pretty basic really.
Although controllers and pumps are very cheap for these things now days anyway (just put one in house)

It doesn't help you heat all the time UNLESS you use your waste oil burner as the secondary heat source so its very possible.

Anyway, more ideas for ya perhaps...

Cheers
Justin