. An Overview. A lower RH setting will call for the DH to run more often. kiln/. Appendix B . 1998. Apply foil tape to the edges of the main baffles to help protect the Styrofoam. Go to the second letter designation (the MC Class Designation) and find the corresponding MC ranges in the table below. /Name /ImagePart_0 Windows and doors are also sealed, as well as any holes cut for electrical service. Moisture content step schedules can be converted to schedules based on time once a kiln operator develops a data record from at least 6 different kiln runs with lumber of the same thickness and species. This lets the operator sort stacks by lumber species, so they will be easy to retrieve when the drying cycle is complete. I chose double wall construction with 1/2 sheathing, and 1/2 T1-11 siding. 0000001186 00000 n I'm thinking I could vent it manually, but with the RH so high externally I am not sure if that is the right thing to do. Every Nyle Dehumidification Dry Kiln System Example: If the WBT falls below the set parameter measures and regulates internal kiln conditions the system will turn on the spray system. Most species of hardwood lumber can be safely dried this way, once the moisture content is 20% to 25% or less. Changing the position of the doorway in various kiln setups helps provide the best access to the stacks of lumber. Place a 1x6 board on the floor behind the stack, tilted to a 45 angle. The cost associated with shed construction was similar to buying a prefabricated kit. Gen. Tech. The dry kiln operator is fully in control, with the ability to make changes as the dry kiln schedule is executing. I recently picked up a back issue of American Woodworker, #94 June 2002, that has a good article on constructing a simple DH kiln. Among dimension lumber, the 2- by 4-inch size is typically the most susceptible to warp for a variety of reasons. endstream endobj startxref The first thing to consider when designing a shed kiln is size. Perhaps the best part: you wont need to calculate your lumber needs down to the board foot. I hope that the sawyer coated the ends of the lumber with Anchor-Seal or oil-based paint when it was green. If you use a lot of lumber, and youre a decent hand at carpentry, a shed kiln will quickly pay for itself. Equalizing and Conditioning A heavy-duty 1,500-watt space heater works fine. In addition, weight on top of the stack can be helpful, but nothing replaces baffles for the best lumber yield. A higher humidity setting will run the unit sporadically to maintain that RH. This report contains suggested dry kiln schedules for over 500 commercial woods, both temperate and tropical. When that is the case, I know Ill have usable lumber in just a few weeks. The membrane was taped and lapped to the weather so if the tape ever fails, any rain that gets behind the siding would still be shed down and away by the HomeWrap. 0000000591 00000 n However, the natural light and ventilation offered by a small window outweighs any disadvantages. Please refer to Appendix A which shows the Lumber Dry Kiln Bill of Materials. The schedules are all moisture content based, using the moisture content of the wettest half of the kiln samples. Kiln Systems. Select a heater with an adjustable thermostat and a tip-over shutoff. /Filter /JBIG2Decode Installing a window in a kiln may seem counterintuitive at first, because windows lose more heat than an insulated wall. These well-known dehumidification kiln packages have been among our bestselling products for the past 30 years. 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. >> Table 1 shows a typical drying schedule for sugar maple. 0000006297 00000 n Case hardening is a defect caused by the outer portion of a board drying quickly, while the inner portion dries more slowly. Custom Doors, Drawers & Glass Accessories, Using a Small Scale Dehumidification Kiln, Learn Woodworking Tips & Tricks with Rockler, High-quality brands and products you can trust, Expert advice and free post-purchase support, Exclusive, innovative products that help you Create with Confidence, Detailed instructions, technical specs and guides to make the most of your purchases. 0000001417 00000 n A shed kiln is an attractive alternative for a couple of reasons. Once all the lumber is stacked and stickered, place baffles over the lumber. Dehumidification: This kiln-drying process requires the use of a heat pump system to remove water from the wood. End baffles are also a good idea to prevent airflow from bypassing the stack entirely. I often buy from sawyers or homeowners at 40% to 50% of retail price. In Fig. Do not know just how the end point of moisture would compare. A dehumidification kiln makes sense particularly when the lumber is air-dried first. This returns some moisture to the very dry exterior of the lumber, while not affecting the core moisture level. Kiln schedules are completely assembled and written out for easy use. Kiln dried wood typically sells for a third more than green lumber and eliminates the need for . Another reason I like the idea of a shed kiln is the flexibility of future use. Vacuum Kiln Drying. For the sterilization phase, air temperature needs to be around 140 F, for three to five hours. Ciencia y Tecnologia, Duygu Kocaefe, Ayhan Aytin, The Bolivian secondary forest products industry has experienced substantial growth during the last 10 years. Size and placement of the access door are critical as well. . Without baffles, the top layers of lumber experience potato chipping with cupping, twisting or warping. Dehumidification Kiln Drying. A small electric heater supplies auxiliary heat to maintain adequate kiln temperature. At the end of the cycle I have the opposite problem. The water tray can be removed and emptied manually, or a hole can be drilled through the wall of the shed to pass a drain tube. Among the various sizes of southern yellow pine (SYP) dimension lumber, 2 by 4 is produced in the greatest volume. Different species should not be loaded simultaneously into the kiln due to often differing kiln schedules. If your lumber stack is built on starter blocks, you will need to limit airflow there as well. Can also be used on any mobile device! 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. To condition the lumber, I introduce steam into the kiln for about two hours. A variety of wood drying kiln technologies exist today: conventional, dehumidification, solar, vacuum and radio frequency. 0000001208 00000 n Then align each subsequent layer of stickers over the last. Sign In Upload. 0000002536 00000 n Difficult-to-dry species might not exceed 60 C (140 F). Case hardening is a defect caused by the outer portion of a board drying quickly, while the inner portion dries more slowly. (I have found that remotely monitoring the temperature and humidity with a WiFi sensor can be very helpful. The conversion method described in the Dry Kiln Operator's Manual is not really accurate, but it is safe. For all kiln drying schedules, a heater should be used to sterilize the lumber and kill any insects that may be present. (See the following sections for a discussion of how to develop a schedule from these designations.) The baffles direct airflow over and through the stack and prevent the top layers from drying too quickly. For a kiln temperature of 140 F, sterilization takes three to five hours. The column on the right I added part way through is the kiln's internal RH. 0000002827 00000 n Place the one inch sections in an oven 215F to 218F (102C to 103C) and dry - usually 18 to 36 hours depending on the oven. Our capacities are 4,000 board feet in a kiln . In the third column, write down the appropriate dry-bulb temperatures. Select 3/4" conduit brackets for hanging baffles on 1/2" galvanized pipe. Soon the DH wont show much water collected in the tray. Dehumidification kilns from Nyle Systems in Brewer, Maine. I cannot stress the importance of baffles enough. They are normally mounted in the gable of household attics, and they are designed to be used in high temperature environments. My kiln uses four ceiling-mounted fans, each rated for 1,600 CFM. Heat comes primarily from an integral dehumidification unit that also removes . A lower RH setting will call for the DH to run more often. Not bragging or anything! KD150 Series dehumidifier pdf manual download. An anemometer confirms that your effort constructing baffles was worthwhile. There are two ways to remove water from the DH unit, and they both work well. The starter blocks should be as long as the stack is wide. As a result, the kiln schedules were too severe. Most species of hardwood lumber can be safely dried this way, once the moisture content is 20% to 25% or less. More than 75 percent of the existing hardwood dry kilns in the United States are steam heated, are humidity controlled and have reversible fans inside the kiln. The stickers are uniform in size and usually 3/4 or 1 square. If you cannot find exact match, look at SG of same family species. Although I can maintain the 90 degree temperature, I could not start at the recommended humidity level unless I added humidity. There is a way to do the conversions and there is a chart published by Nyle to do it, if you want to do some academic exercise. For the sterilization phase, air temperature needs to be around 140 F, for three to five hours. Instead of using expensive electrically reversible fans designed for commercial kilns, I came up with a simple hardware solution. 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. Basically, you dont want all of the air rushing out under the stack, so find a way to redirect it. Low temperatures can be used for an extra safety margin on greener lumber. Additionally, I have been underwhelmed by the performance of solar-operated fans. The baffles do not need insulating properties, and plywood would work just as well. Also check that air isnt escaping around the side baffles or under the stack of lumber. 73. They are based on different air flow rates, etc. There may be more depression values than required; ignore the extra depression values in this table. Go to the second number designation (the wet-bulb depression designation) and find the corresponding depressions in the table below. Main thing is to not rush drying in first stages, as this will cause problems. Once all the lumber is stacked and stickered, place baffles over the lumber.