The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns


Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.




Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL


Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades

Turbosawmill

Sawmill Exchange

Michigan Firewood, your BRUTE FORCE Authorized Dealer

FARMA


Baker Products

ECHO-Bearcat

iDRY Wood Lumber Vacuum Drying for everyon

Nyle Kiln Dry Systems






Author Topic: Solar kiln with dehumidifier  (Read 1524 times)

0 Members and 1 Guest are viewing this topic.

Offline Classic1

  • member
  • *
  • Posts: 28
  • Location: St. Petersburg, FL
  • Gender: Male
  • I'm new!
    • Share Post
Solar kiln with dehumidifier
« on: September 12, 2018, 11:03:45 PM »
Iíve got two 40í shipping containers Iím going build into solar kilns, I was wondering if anyone had just added a commercial dehumidifier into one of them and just run on a timer to kick on and off at varying times during drying cycle to speed things up?  Iím in central FL.  Heat is not an issue.  Any thoughts on controlling this setup?   

Lucas dsm23
Norwood hd36

Offline pineywoods

  • Senior Member x2
  • *****
  • Posts: 5156
  • Age: 83
  • Location: Marion, Louisiana
  • Gender: Male
  • Engineering analysis-just sittin thinkin about it
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #1 on: September 12, 2018, 11:37:07 PM »
I have done just that using a framed-up enclosure. I air dry first, then stack in the kiln, turn on the fans and de-humidifier and go away for a few days. MY kiln has NO vents. The de-humidifier will add a good bit of heat. Another local sawyer has a similar setup. He successfully dries oak lumber for cabinet shops. Drawback. The dehumidifiers don't last very long in a kiln environment. just trash them when they quit. buy them at flea markets for $15 /$20
1995 Wood Mizer LT 40, Liquid cooled kawasaki,homebuilt hydraulics. Homebuilt solar dry kiln.  Woodmaster 718 planner, Kubota M4700 with homemade forks and winch, stihl  028, 029, Ms390
100k bd ft club.Charter member of The Grumpy old Men

Offline GeneWengert-WoodDoc

  • Senior Member x2
  • *****
  • Posts: 2769
  • Location: Bishop, GA
  • Gender: Male
  • Author of "Sawing Hardwood Lumber"
    • Share Post
    • Book on Sawing hardwood Lumber
Re: Solar kiln with dehumidifier
« Reply #2 on: September 13, 2018, 04:44:13 PM »
A dehumidifier improves the kiln's performance as vents are kept closed with air dried lumber, but it does cost electricity to run the DH.

A special note about worn out dehumidifiers.  Like refrigerators, freezers and window air-conditioning units, dehumidifiers contain an environmentally hazardous refrigerant material that damages the ozone layer, although not as badly as Freon from old units.  It is illegal to dispose of such items without first removing and capturing the refrigerant, which is a dangerous procedure that requires a certified technician. Local recycling or bounty programs ensure your appliance is disposed of legally, but they may have a small charge.  The captured gas is then treated to avoid environmental damage.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Offline OutlawB52

  • member
  • *
  • Posts: 25
  • Age: 65
  • Location: The real South Jersey
  • Gender: Male
  • I'm new!
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #3 on: September 13, 2018, 10:37:27 PM »
Are you going to set the 40 ft container under direct sun and just put a dehumidifier in it ?  I am sure there is more to it .  

Offline Classic1

  • member
  • *
  • Posts: 28
  • Location: St. Petersburg, FL
  • Gender: Male
  • I'm new!
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #4 on: September 14, 2018, 01:05:08 AM »
Iím a general contractor by trade, the lumber business has been a secondary business Iím developing.  The dehumidifier I was thinking of purchasing are the ones used in mold abatement and restoration in the construction industry. They are commercial duty units made to run in nasty environments.  I can get on that removes 130 pints of water a day, draws 8 amps, and has 325 cfm of air movement for just under 2k new.  Used market has them well under a thousand.   

Seems like I could calculate load and moisture removal based on tables and just time how often the dh unit runs.  Would have to be a lot faster than just air drying. 

Any issues on that?
Lucas dsm23
Norwood hd36

Offline GeneWengert-WoodDoc

  • Senior Member x2
  • *****
  • Posts: 2769
  • Location: Bishop, GA
  • Gender: Male
  • Author of "Sawing Hardwood Lumber"
    • Share Post
    • Book on Sawing hardwood Lumber
Re: Solar kiln with dehumidifier
« Reply #5 on: September 14, 2018, 07:42:35 AM »
As many species of wood are quite acidic, the commercial DH units for wood drying use coils that are coated to protect them from corrosion.

A wood like oak or maple will lose around 30 pints per 1000 bf for each 1% MC loss.

I assume your 8 amps is at 220 volts.  So, that means 1.8 kWh or around a $2 per day for DH power.  Then there is fan power and heat power too.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Offline WDH

  • Forester
  • Administrator
  • *****
  • Posts: 29514
  • Age: 66
  • Location: Perry, GA
  • Gender: Male
  • April 1998 - August 2008
    • Share Post
    • hamsleyhardwood.com
Re: Solar kiln with dehumidifier
« Reply #6 on: September 14, 2018, 08:10:46 AM »
Why not just go with a unit like the Nyle L53 and be able to control the drying without guessing?
Woodmizer LT40HDD35, John Deere 2155, Kubota M5640SU, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Offline Classic1

  • member
  • *
  • Posts: 28
  • Location: St. Petersburg, FL
  • Gender: Male
  • I'm new!
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #7 on: September 16, 2018, 01:19:14 PM »
Well,  the L53 runs almost $4k but says its rated for 1000bdft.   I've got two 40' shipping containers, the L200 would be more appropriate I'm sure but runs $7700 each.  

The dehumidifiers I'm talking about are commercial units, made to run non stop, in harsh environments.  They are easily serviced and maintenance on them is straight forward.  They have 1 year parts/labor warranty and 5-6yr compressor warranty dependent on brand.   

The equivalent dehumidifier to the L53 specs would be under $1k brand new.   For the larger unit that I described in the previous post, it pulls 15+ gallons of water a day (those are at lower RH and temps)  Roughly double the L53 and can be had for $2000 new.  Going up from there I can get a unit that pulls 40+ gallons of water a day for $2600 that is a high temp model, all stainless construction, epoxy coated coils, etc.  That unit is ductable on intake and exhaust also so I could run the unit outside of the container if I wanted.  Not sure if its necessary as the controls on this are not electronic and are al solid state.  

I'll probably pickup one of these and start logging results.   

Gene,  would you advise to run this during the day when temps are up?  Has an operating range to 125F.  Or would it be better to run the unit at night?  Or cycle it on and off via a timer or other control?   I don't think I'm at risk of drying my slabs to fast with the amount of board footage in the kilns, but... I'd rather go at this in a manner that makes sense. 
Lucas dsm23
Norwood hd36

Offline GeneWengert-WoodDoc

  • Senior Member x2
  • *****
  • Posts: 2769
  • Location: Bishop, GA
  • Gender: Male
  • Author of "Sawing Hardwood Lumber"
    • Share Post
    • Book on Sawing hardwood Lumber
Re: Solar kiln with dehumidifier
« Reply #8 on: September 16, 2018, 06:30:22 PM »
Consider this option:  One L200 can potentially run two containers (with insulated, adjustable ducting) with separate heaters better than two L53.  You will have to work harder when different species or different MCs are in the two units.  
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Offline GeneWengert-WoodDoc

  • Senior Member x2
  • *****
  • Posts: 2769
  • Location: Bishop, GA
  • Gender: Male
  • Author of "Sawing Hardwood Lumber"
    • Share Post
    • Book on Sawing hardwood Lumber
Re: Solar kiln with dehumidifier
« Reply #9 on: September 16, 2018, 06:37:43 PM »
One really essential consideration is that the solar kiln based on VT design  is very energy inefficient when the sun has set or even a few hours after sunrise and before sunset.  The poor performance is from the collector.  So, instead of the clear roof, have an insulated roof on the kiln and then build a separate solar collector.  Maybe this could be done easiest by making the kiln with an insulated flat roof and then put a sloped chamber on top of this.  The kiln and the collector would be isolated from each other at night (vents closed).  DH can run most effectively at night.  Make sense?
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Offline farmfromkansas

  • Full Member x2
  • ***
  • Posts: 172
  • Age: 68
  • I'm new!
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #10 on: September 17, 2018, 02:40:21 PM »
 What is the brand name of the dehumidifiers you are considering?

Offline Southside

  • Administrator
  • *****
  • Posts: 5617
  • Age: 47
  • Location: Wilsons (Dinwiddie County), VA
  • Gender: Male
  • Have a plan to saw every log you meet.
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #11 on: September 17, 2018, 05:41:54 PM »
What do you have for a solution to the controllers? The Nyle units will cycle the compressor on and off depending on wet bulb settings, important with some species. Also, what about sterilization / heat treatment / pitch set. Air temp of 125 is a bit low per the USDA standard.

I can appreciate the desire to save money, but often you are money ahead by using the right tools and focusing on what it is about your business that makes money. I doubt you make money checking on readings every hour, rather it is made sawing and selling slabs. 
Franklin buncher and skidder
JD Processor
Woodmizer LT Super 70 and LT35 sawmill, KD250 kiln, BMS 250 sharpener and setter
Riehl Edger
Woodmaster 725 and 4000 planner and moulder
Enough cows to ensure there is no spare time.

Offline Classic1

  • member
  • *
  • Posts: 28
  • Location: St. Petersburg, FL
  • Gender: Male
  • I'm new!
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #12 on: September 17, 2018, 10:43:15 PM »
Iíve done nothing special on the construction of the kiln. Basically just have two 40í HC shipping containers painted a dark navy blue sitting in full sun exposure. Doesnít take long for them to heat up in the morning as by 9am theyíve had quite a bit of sun on them. Theyíll be 110f or so by then.  Heat of the day itís up over 120 easy.  If we painted them black Iíd think weíd pickup 10f.   

I donít want to insulate them, I donít want to use electric heaters.  Pointless where I am in Florida. 8 months of the year here our average highs are over 80f.   I donít need to turn over a kiln load every 2 months.  Right now weíre air drying, if I could get a full load done in 4-5 months that would be awesome. That would be 6-8k bdft conservatively  2-3 Times a year.  Iím ok with that. 

Everyone says I need to insulate but I canít imagine that being a huge issue, if I have 4K bdft of lumber thatís a lot of mass inside that sealed container.  My schedule from my thinking at that point would be to shutdown the circulation fans at maybe 8pm.  Then cycle on the dehumidifier through the night.  As the lumber cools the retained moisture in the air should condense and the dehumidifier will do its job.  I wouldnít think it possible to dry something to quickly with this method.  And anything at this point is an improvement over air drying.   Thoughts? 

Really trying to make this as simple as possible. 
Lucas dsm23
Norwood hd36

Offline Classic1

  • member
  • *
  • Posts: 28
  • Location: St. Petersburg, FL
  • Gender: Male
  • I'm new!
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #13 on: September 17, 2018, 10:46:08 PM »
Lucas dsm23
Norwood hd36

Offline Mfrost459

  • member
  • *
  • Posts: 28
  • Age: 60
  • Location: Winston, Georgia
  • Gender: Male
  • Exploring a new adventure everyday!
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #14 on: September 17, 2018, 11:03:59 PM »
Insulating the container will help it hold the heat longer. I live in Georgia and it gets really warm during the day here too. My container will hold the heat well past sunset. Really doesnít start to get around 100 degrees till around 10 pm. 
Have a great day milling!

Offline Classic1

  • member
  • *
  • Posts: 28
  • Location: St. Petersburg, FL
  • Gender: Male
  • I'm new!
    • Share Post
Re: Solar kiln with dehumidifier
« Reply #15 on: September 18, 2018, 07:53:44 AM »
Insulation will keep the heat out too.  Unless I run a separate solar heat collector and blow in hot air from that. The insulation will hurt me more.  Also, Georgia gets snow. Your winters are much different than central fl on the coast.  We stay much warmer.   
Lucas dsm23
Norwood hd36


Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter

xx
Dehumidifier In Solar Kiln

Started by Woodslabs on Drying and Processing

1 Replies
836 Views
Last post October 19, 2015, 10:54:36 PM
by pineywoods
xx
Dehumidifier In A Solar Kiln

Started by Tree Feller on Drying and Processing

5 Replies
2595 Views
Last post February 28, 2013, 08:48:19 PM
by Goodndusty
xx
converting solar to Dehumidifier over winter

Started by Woodslabs on Drying and Processing

10 Replies
1365 Views
Last post April 05, 2016, 03:41:16 PM
by Fedge
xx
Can I Use This Dehumidifier for Kiln

Started by Believer on Drying and Processing

8 Replies
2824 Views
Last post June 05, 2013, 09:35:52 AM
by Planman1954
 


Powered by EzPortal