Understand how kiln performance must be modified to permit the use of custom schedules for specific product applications; Be able to modify existing conventional kiln schedules to dry products in dehumidifier kilns; Recognize degrades common to various species, including hardwoods, and modify handling practices to minimize these The KD150 Dehumidification Kiln Kit is a compact, entry-level dehumidification kiln for drying lumber between 300 and 1000 board feet. Dehumidification dry kiln construction plans However, because wood from They are easy to use and give you precision control over your drying. WOODWEB is a registered trademark of Woodweb.com. The T-bars are made from 1/2 galvanized pipe and are attached to the rafters with threaded pipe flanges. If you intend to kiln dry lumber from a green state, right off the sawmill, you will need to be well-versed in airflow rates and follow a detailed drying schedule. Vote. I usually see a large volume of water in the DH each night when I check the kiln. There are two main reasons for drying wood: Woodworking When wood is used as a construction material, whether as a structural support in a building . Formulating a Kiln Schedule The last thing to do before starting the kiln is to close the gable vent with an insulated cover. Our approach was to build and operate a small dehumidification dry kiln. Once the flooring deck is constructed, think about sealing the shed framing at every opportunity. Manufacturer guarantees/warranties for power tools, CNC and laser products will supersede the Rockler Guarantee if these items are damaged or defective. Minus the drying equipment, a shed kiln is just an insulated storage space, with a host of possible uses. For 4/4 hard maple, with an initial temperature of 90F and an initial relative humidity of 81%, the SDR was given as .0061 pints per hour per board foot. Additionally, a 12 air plenum is required between the walls and stacks of lumber. Drying lumber too quickly can lead to deep end checking, warping and case hardening. 301 0 obj <>stream 5. Adjust the baffles or fan direction to achieve good airflow. You won't ever have the fastest kiln in town, but it can still work. I recently picked up a back issue of American Woodworker, #94 June 2002, that has a good article on constructing a simple DH kiln. I have sensors in the kiln for moisture levels & probes in the center of the wood attached to a lignomat moisture meter. In the majority of cases, the drying schedules are from the world literature, with emphasis on U.S., Canadian, and British publications. Sorry, preview is currently unavailable. Technical Heat Treatment Guidelines and Operating Conditions Manual Attic fans are a perfect way to provide airflow over the stacks of lumber. Small, complete dehumidification dry kilns under 5,000 board-foot capacity are not available for sale. 158 p. Dry kiln schedules for commercial woods : temperate and tropical. . Kiln Drying In The Lake States - What Happens Inside A Lumber Dry Kiln organization in the United States. 0000000591 00000 n Should a Moulding Mill Bring Sawmill Operations In-House? The order was 540 board feet (BF) of 5/4 white oak. For a kiln temperature of 140 F, sterilization takes three to five hours. I decided on a dehumidification kiln after reading an article in Fine Woodworking (1991). In contrast, a dehumidification kiln uses a sealed chamber, with only enough energy input to maintain the desired temperature. Go to the second number designation (the wet-bulb depression designation) and find the corresponding depressions in the table below. Oregon-based HDE Dry Kilns has launched a new line of small kilns ranging from 2,000 to 12,000 board feet. HT systems use 40-60% less energy than gas-fired or steam dry kilns. It uses a simple humidistat to control the dehumidifier, and a remote bulb thermostat to control the heater, which is a couple of light bulbs. I don't remember how the air flow was arranged in the kiln in the magazine, but it sounds like that could be a problem for you. The stickers are uniform in size and usually 3/4" or 1" square. Select 3/4 conduit brackets for hanging baffles on 1/2 galvanized pipe. My baffles hang from T-bar assemblies mounted to the ceiling. Created and Presented by: Henco Viljoen and Elijah McCarty with Nyle Dry Kilns. %PDF-1.4 % ) or https:// means youve safely connected to the .gov website. I've been drying hardwood lumber in this Sauno dehumidification kiln for 4 years with excellent results. Without baffles, the top layers of lumber experience potato chipping with cupping, twisting or warping. A bead of silicone caulking between the subfloor and sill plate will prevent air infiltration. 0000004213 00000 n I am using a household . For single-stack kilns, stationary fans are adequate. Projects included design, construction, installation and commissioning of heat-pump based dehumidification equipment for seafood and fish gelatin products, hardwood lumber kilns and laboratory testing. Milling the stickers square is advantageous over a rectangular cross-section, because no matter how you place the stickers they will form a level stack. )f7haRoMRhib5Sd|-=RBkBBN r-hzf+1\IFgk;v]3_, KxL$9oL "Qw#"BFGfk}>cT2g yP K|7@N*v9!Wy9jB. op(y"X)Fz"q]fQC/ha>7=k_p}}^VXQmj e'2fyXQ{~23X^H1,d>Hq|^KQ*cN=yF%z. Regardless of size, allow for a 36 door that opens to a hallway of open space. I am also curious why an initial temperature of 90F would have been selected. . Share sensitive information only on official, secure websites. I know mixed loads are taboo, but this one worked well, other than the horse chestnut. JavaScript seems to be disabled in your browser. Each layer of lumber is separated from the next by a series of stickers or spacer sticks. /Type /XObject In smaller kilns, the heat generated by the fans and DH motor is sufficient to maintain temperatures in excess of 100 degrees. The store will not work correctly in the case when cookies are disabled. Another common sticker size is 1" x 2", and these work fine as well. You could use the dehumidifier to dry wood but it would not be part of a "kiln." Just be a different process. This would allow a stack of lumber four feet wide and 10 feet long. 0000001208 00000 n The fact is, most of my stacks of lumber air dry to 15% moisture content before entering the kiln. This report contains suggested dry kiln schedules for over 500 commercial woods, both temperate and tropical. A maximum 45 F depression often produces better lumber. For these reasons, I feel it is best to let the shed breathe, and forgo a plastic vapor barrier. This slows the end-grain drying and limits the severity of end checking. Dehumidification dry kilns operate at lower drying temperatures (typically below 150F) than do conventional kilns, which results in longer drying schedules. Appendix B . Using a Small Scale Dehumidification Kiln - Rockler Woodworking And The dry kiln operator is fully in control, with the ability to make changes as the dry kiln schedule is executing. In addition, weight on top of the stack can be helpful, but nothing replaces baffles for the best lumber yield. Many articles have been dedicated to solar lumber kilns: everything from a simple sheet of Visqueen over a stack of lumber in the sunshine to elaborate enclosures designed for solar gain. The starter blocks should be as long as the stack is wide. So, if you have 100 bf in the kiln, every 12 hours you would extract (12 hours *100bf * .0061 SDR) = 7.3 pints of water. Dehumidification Kiln. Kiln dried wood typically sells for a third more than green lumber and eliminates the need for customers to incur costs associated with drying lumber . Another reason I like the idea of a shed kiln is the flexibility of future use. 282 0 obj <> endobj Vacuum Kiln Drying. A higher humidity setting will run the unit sporadically to maintain that RH. They are based on different air flow rates, etc. _ Academia.edu no longer supports Internet Explorer. My four main baffles consist of sheets of 1" Styrofoam insulation. Place a sticker at each end, and every 16" along the stack for 4/4 stock. Wood Kilns - Wood-Mizer Australia Excel Program for Modeling Lumber Dry Kiln Operations - a model for lumber dry kiln operation. I use a Rockler steam generator. are generally kiln dried by time scheduleswhether the wood is intended for struc-tural lumber or for appearance uses, such as furniture or millwork. Determine the equalization settings and conditioning settings, as required. For 4/4 hard maple, with an initial temperature of 90F and an initial relative humidity of 81%, the SDR was given as .0061 pints per hour per board foot. Should I? Milling the stickers square is advantageous over a rectangular cross-section, because no matter how you place the stickers they will form a level stack. Typical . Temperatures inside the kiln range from 120 to 190 degrees F, depending on the stage of . Go to the second letter designation (the MC Class Designation) and find the corresponding MC ranges in the table below. /BitsPerComponent 1 At the end of the cycle I have the opposite problem. stream Do not know just how the end point of moisture would compare. In the third column, write down the appropriate dry-bulb temperatures. There may be more depression values than required; ignore the extra depression values in this table. Many available kiln designs require a large, heavy door. of this publication is to make available to dry kiln operators and others interested in kiln-drying wood, kiln schedules that are completely assembled and written out for ready reference and easy use. . I hope that the sawyer coated the ends of the lumber with Anchor-Seal or oil-based paint when it was green. An anemometer confirms that your effort constructing baffles was worthwhile. PDF An Overview of Drying Hardwood Lumber Application of Heat Pump Dehumidification : A Case Study : Drying Dehumidifier suggestion: http://amzn.to/2iYZqVZThis is the first in a series of videos showing how I built a kiln for drying lumber. %3.3 This shed will be essentially unheated for much of the year and very hot during the kiln-drying cycles. Dehumidification Kilns | Nyle Systems | Brewer, Maine /Length 7 0 R 73. Keenan Slab Works has a vacuum kiln located at 4917 Elizabethtown Road, Manheim, Lancaster County, Pennsylvania, 17545 and is expanding services for the general public to have their slabs and lumber vacuum dried. For sterilizing thicker lumber, additional time is required. Schedule for drying 4/4 and 5/4 upland red oak in a steam dry kiln. Select 3/4" conduit brackets for hanging baffles on 1/2" galvanized pipe. (Note: This letter designation is related to the green MC of the species. Abstract. Nyle. HWn8gXA N,[mKJr2"Ec9,t An outswing door can always be opened, regardless of shed contents. Drying small amounts of lumber using a dehumidification kiln is a suitable option for woodworkers even with limited knowledge of kilns. INDUSTRIAL DEHUMIDIFICATION DRYING OF SOFTWOODS - Oregon State University 3.) For end baffles, I use 2-thick rigid foam insulation screwed to the main baffles. I modified one of the Radio Shack combo units so it could measure the RH remotely as well as the temp. I prefer to empty the water tray manually and record the volume of water collected. The stickers are uniform in size and usually 3/4 or 1 square. The kiln humidity can be expressed as an EMC, relative humidity, or wet-bulb temperature. Operation and cost of a small dehumidification dry kiln Unfortunately, little information is available regarding lumber drying technology and practices used, which is essential for the formulation of improvement strategies. Adjust the baffles or fan direction to achieve good airflow. This procedure is discussed in a following section. This allows for a more gentle kiln schedule to fully dry the timber. This problem is magnified if the lumber is thin or flatsawn. This plan allows . The second most common type of drying is called dehumidification drying. Conventional kiln drying. Sticker spacing can be increased to 24 apart for 5/4 or thicker hardwood. This air space is absolutely critical for even airflow, so count on the extra floor space right from the design phase. The baffles do not need insulating properties, and plywood would work just as well. Frequently, the lumber has already air-dried for several years in a barn or outbuilding. However, if you kiln dry hardwood lumber that has already been air dried, the process is much more forgiving. The last step requires a short period of high humidity to relieve the drying stresses in the boards. Kiln drying is the process of drying wood in a controlled environment, where temperature, air circulation and humidity are monitored and stabilized. In Fig. squares, handle stock, gunstock blanks) are given for many species. Hardwood Lumber Kiln Schedules A household dehumidifier (DH) removes moisture from the kiln chamber. Unlike general shop space, bigger is not always better for kiln design. Cost and operation of a Small dehumidification dry kiln - ResearchGate Choosing a Kiln Schedule Ignoring for a moment the merits of a homebrew DH kiln versus a Nyle, I was curious to see that rather than referencing the standard kiln schedules (e.g. Considerations in Drying Hardwood Lumber | MU Extension Loading the kiln begins by rousing my sons and letting them know Ive planned a day of work. For equalizing, use an EMC 2% below the target MC at a dry-bulb of 170 F. For conditioning, use an EMC 4% above the target MC at a dry-bulb of 180 F. Professor Gene Wengert is Extension Specialist in Wood Processing at the Department of Forestry, University of Wisconsin-Madison. I then manually rotate the fan boxes halfway through the drying cycle. HDE Dry Kilns Launches Line of Small Kilns | Timberline Magazine Equalizing and conditioning are required for almost all hardwood lumber. Dehumidifier Kiln Schedule | Dehumidifier Supply 0000001186 00000 n Place some sample boards in the stack that will be easy to pull out for moisture testing later. This gives me a secondary method of tracking the drying process, using both water volume and moisture content (MC) readings. The schedules can also be formulated manually as follows. Module 6 - Advanced Schedule Development - Centre for Advanced Wood For the best experience on our site, be sure to turn on Javascript in your browser. The kiln humidity can be expressed as an EMC, relative humidity, or wet-bulb temperature.