Items shipped directly from the manufacturer cannot be returned in store. Would adding humidity at the start, bringing the initial relative humidity rate to 87% as suggested in the table, result in better product or faster drying? Basically, you don't want all of the air rushing out under the stack, so find a way to redirect it. Drying lumber too quickly can lead to deep end checking, warping and case hardening. 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. Unlike general shop space, bigger is not always better for kiln design. All of these products were purchased at a local home center, except the remote hygrometer/thermometer which was purchased at a local electronics store. However, because wood from I know your kiln is absolutely tight and perfectly sealed, but it has to vent some or it would overheat. Abstract. With a well-designed dehumidification kiln, hardwood lumber can be dried for mere pennies per board foot. Equalizing and conditioning are required for almost all hardwood lumber. Kiln schedules are completely assembled and written out for easy use. In time schedules, dry- and wet . Attic fans are a perfect way to provide airflow over the stacks of lumber. A maximum 45 F depression often produces better lumber. 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. A shed kiln has minimal venting (usually one or two gable vents) and sealed soffits. After seven to 10 days, I reverse the fan direction to make sure all stacks of lumber dry evenly. I then manually rotate the fan boxes halfway through the drying cycle. Dehumidification kilns from Nyle Systems in Brewer, Maine. Question /Width 1628 Attic fans are a perfect way to provide airflow over the stacks of lumber. This plan allows . Equalizing and Conditioning (See the following sections for a discussion of how to develop a schedule from these designations.) Lock Using a piece of paper with 6 columns, write down the Schedule Step numbers in the first column on the left. I chose double wall construction with 1/2 sheathing, and 1/2 T1-11 siding. Dehumidification drying system. Soon the DH won't show much water collected in the tray. For a kiln temperature of 140 F, sterilization takes three to five hours. Table 1 shows a typical drying schedule for sugar maple. The velocity through the load is assumed to be between 275 and 350 fpm, except for the white woods (including maple, ash, basswood, hackberry) where higher velocities (up to 600 fpm) are desired and acceptable. Low Temperature Kiln Drying Systems (120F) 300BF - 4000BF Capacity . I find that unplugging the DH is helpful during the sterilization phase so I can add a second heater, without overwhelming my electrical circuit. /Subtype /Image The kiln climate is controlled by venting the hot air and replacing it with ambient air. Place a sticker at each end, and every 16 along the stack for 4/4 stock. If severe enough, the lumber can develop honeycomb cracks throughout. The approach described in the article where you try to keep the water leaving at a steady rate is fine. For the best experience on our site, be sure to turn on Javascript in your browser. For more capacity, consider a two stack kiln (12 x 12), or a three-stack kiln (12 x 16). However, if you kiln dry hardwood lumber that has already been air dried, the process is much more forgiving. Low Temperature Kiln Drying Systems (120F), High Temperature Kiln Drying Systems (160F), Very High Temperature Kiln Drying Systems (220F), Website Content Copyright 2023 Nyle Systems |, Affordable and easy method to accomplish top quality lumber drying, Designed specifically for any sized operation, Modular based systems for unlimited capacity, No boiler or steam required with gas furnace, Can be installed along side existing kilns, Chambers are sized with our DH systems to meet your lumber drying requirements. Corrosion resistant epoxy coated aluminum cabinets and specially coated dehumidification coils for an extra long life. Different species should not be loaded simultaneously into the kiln due to often differing kiln schedules. In larger kilns, the heater may be needed in the latter part of the drying cycle. I usually see a large volume of water in the DH each night when I check the kiln. Whether to Wax Walnut Ends Before Steaming, Frequently Asked Questions about Widebelt Sanders. Diy dehumidifier kiln time table. Many regions have increased the shed and outbuilding maximum allowable size without need for a permit. 9. I had these custom cut and I air dried them outside under a tarp for 6 to 18 months (depending on which load they came in on) and then I kiln dried them in a Nyle dehumidification kiln for 3 months. Select a heater with an adjustable thermostat and a tip-over shutoff. This serves a dual purpose of supporting the rigid foam insulation as well as stiffening the floor framing. This will allow the DH to drain automatically without you needing to enter the kiln. Perhaps the best part: you wont need to calculate your lumber needs down to the board foot. There are two ways to remove water from the DH unit, and they both work well. For a kiln temperature of 140 F, sterilization takes three to five hours. This returns some moisture to the very dry exterior of the lumber, while not affecting the core moisture level. Sign In Upload. Also check that air isnt escaping around the side baffles or under the stack of lumber. Conventional kiln drying. Maderas. I usually see a large volume of water in the DH each night when I check the kiln. Low temperatures can be used for an extra safety margin on greener lumber. hb```[@9p(T-3jO:g)@S 4Y]g7l\V!c!$Bf J B@&xcEz8PH@ZHs1/X$qOq,x'x$0.rWg*d XAT10 );9 Wood-Mizer dehumidification and solar wood kilns range from 300 to 35,000 board feet capacity for drying lumber. 1. a furnace or oven for burning, baking, or drying, especially one for calcining lime or firing pottery. This, of course, is gross savings; we must calculate electrical costs to determine the net savings: in this case, about $62. Academia.edu no longer supports Internet Explorer. In smaller kilns, the heat generated by the fans and DH motor is sufficient to maintain temperatures in excess of 100 degrees. 282 0 obj <> endobj Once the lumber is sterilized, it is ready for the conditioning phase. For all kiln drying schedules, a heater should be used to sterilize the lumber and kill any insects that may be present. 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. Created and Presented by: Henco Viljoen and Elijah McCarty with Nyle Dry Kilns. (Note: This letter designation is related to the green MC of the species. Do not know just how the end point of moisture would compare. The air flow rate through your stacks should be about 350FPM. If your lumber stack is built on starter blocks, you will need to limit airflow there as well. Schedules Dry Kiln Schedules for Commercial Woods In a professional DH kiln, the final climate for oak is 120F and <40>t over-dry it at that rate. Dehumidification Opportunities for Dehumidification Drying Of Hardwood Lumber Dimension Kiln Drying Hardwood Dimension Parts Discoloration Preventing Discolorations in Hardwood and Softwood Logs . Figure 3-4 Drying Schedules Normal Schedule Alternate Schedule Moisture Content Dry Bulb Wet Bulb Dry Bulb Wet Bulb Group 2 Above 45% 90F 85F 100F 97F . 0000002827 00000 n Unfortunately, little information is available regarding lumber drying technology and practices used, which is essential for the formulation of improvement strategies. Soon the DH wont show much water collected in the tray. Drying small amounts of lumber using a dehumidification kiln is a suitable option for woodworkers even with limited knowledge of kilns. It is a good idea to sterilize the lumber at the end of the kiln run. However, the natural light and ventilation offered by a small window outweighs any disadvantages. 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. Our next kiln charge is scheduled to begin around February 6, 2023. You can achieve top-quality results with incredible efficiency. Always avoid conditions that add moisture back to the lumber, especially during start-up. 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. I was hoping someone could point me in the right direction or share experience. If the temperature is below this range, I start the heater and adjust the thermostat accordingly. For the sterilization phase, air temperature needs to be around 140 F, for three to five hours. Go to the second number designation (the wet-bulb depression designation) and find the corresponding depressions in the table below. My question focuses on the initial relative humidity featured in the Safe Drying Rate table. /ColorSpace /DeviceGray If the temperature is below this range, I start the heater and adjust the thermostat accordingly. Website Content Copyright 2023 Nyle Systems |. Once all the lumber is stacked and stickered, place baffles over the lumber. I found that brackets for mounting rigid metal electrical conduit work best. This helps keep the lumber straight during the drying cycle; in fact, improper placement of stickers can permanently deform lumber. It should be double-pane, well-insulated with low emissivity (low-E). The Bolivian wood products industry was surveyed to determine lumber drying capacity, technology and. The stickers are uniform in size and usually 3/4 or 1 square. The four charges of lumber ranged from 600 to 700 board feet (bf), and a woodworker with no dry-kiln experience operated the kiln. If you dry 9,500BF of slower drying Oak, youd use the 10MBF chamber with the HT8 Dehumidifier. To accommodate the floor insulation, blocking between joists is oriented horizontally instead of the normal vertical position. The MC ranges are chosen so that the loss of the first one-third of moisture, and the highest risk of checking and staining, will occur in the first step listed.). However, if you kiln dry hardwood lumber that has already been air dried, the process is much more forgiving. After seven to 10 days, I reverse the fan direction to make sure all stacks of lumber dry evenly. The stickers are uniform in size and usually 3/4" or 1" square. The store will not work correctly in the case when cookies are disabled. KD150 Series dehumidifier pdf manual download. To condition the lumber, I introduce steam into the kiln for about two hours. The kiln schedule information in the tables below has been assembled from many different sources, including drying texts and industrial contacts. I hope that the sawyer coated the ends of the lumber with Anchor-Seal or oil-based paint when it was green. I like these "starter blocks" to raise the lumber a few inches off the floor. Kiln dried wood typically sells for a third more than green lumber and eliminates the need for . trailer << /Size 918 /Info 891 0 R /Root 907 0 R /Prev 482770 /ID[<67858f68421814977b05bc7913f6cc23><4073af979fbabe8f1c016146fd1c21ef>] >> startxref 0 %%EOF 907 0 obj << /Pages 902 0 R /Type /Catalog /DefaultGray 903 0 R /DefaultRGB 904 0 R /Metadata 905 0 R >> endobj 916 0 obj << /S 499 /Filter /FlateDecode /Length 917 0 R >> stream Anyway, I included my log of a load I did in Nov '06 for everyone's amusement. Rocky Mountain . There are many types of kilns, but the most common are dehumidification kilns and conventional kilns. After four days, I decrease the RH setting on the DH to 30% and continue to run the fans. Go to the first number designation (the temperature designation) and find the corresponding temperatures in the table below. Among the various sizes of southern yellow pine (SYP) dimension lumber, 2 by 4 is produced in the greatest volume. Khmer Kiln: quite similar to the Anagama kiln however, traditional Khmer Kilns had a flat roof. This can create internal stress in the lumber that is released when sawing. Heres a classic project that both steps up and provides overflow seating. (Dry Kiln Operator's Manual. Go to the second letter designation (the MC Class Designation) and find the corresponding MC ranges in the table below. A 1.5-kW dehumidifier was installed in the solar dryer to determine the performance of a combined solar-dehumidification dryer. 0000000710 00000 n For DH kilns, use the same RH, but lower the temperature to the typical operating temperature for the compressor; raise temperature to steam values when convenient and possible. . Although dehumidification kilns are slower than conventional kilns for drying, the lower drying temperature has the reported advantage of less degrade and less shrinkage. Should I? Operates at a temperature range from 80F - 160F (26 - 71C). Minus the drying equipment, a shed kiln is just an insulated storage space, with a host of possible uses. In vacuum kiln trials, logs were heated to 56C at 70 percent log radius depth and the temperature maintained for . Align the stickers over the starter blocks on the first course. . This would allow a stack of lumber four feet wide and 10 feet long. A small "m" after the designation indicates that the wet-bulb temperatures should be adjusted to avoid temperatures below 90 F. See the above mentioned publication for details. If your lumber stack is built on starter blocks, you will need to limit airflow there as well. Case hardening is a defect caused by the outer portion of a board drying quickly, while the inner portion dries more slowly. There may be more depression values than required; ignore the extra depression values in this table. This is because it needs to be dried to a lower moisture content than wood will air dry to outdoors. A better choice might be a solar kiln, as you can dry wood from "wet" to 6-8 percent MC in 6-8 weeks. Dehumidification Kiln Drying. Insulation for walls and ceilings should be a minimum of R13. building the dehumidification dry kiln. With a 130 F kiln temperature, sterilization will take 10 to 12 hours (Dry Kiln Operators Manual, 1991). Saving money by drying your lumber may not be the answer for every woodworker, but the basics shown here demonstrate that it is within the reach and skills of the average person. Q,kjifT33P[! When that is the case, I know Ill have usable lumber in just a few weeks. Once all the lumber is stacked and stickered, place baffles over the lumber. 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. Dehumidification: This kiln-drying process requires the use of a heat pump system to remove water from the wood. _0e`bd\ p@ After four days, I decrease the RH setting on the DH to 30% and continue to run the fans. I am removing water about 50% below the SDR. To condition the lumber, I introduce steam into the kiln for about two hours. Select 3/4 conduit brackets for hanging baffles on 1/2 galvanized pipe. Recently, either Wood, or American Woodworker showed how to build a small version of a solar kiln. Consider not only the space for the lumber stacks, but extra floor space to easily load and monitor the charge of lumber. An outswing door can always be opened, regardless of shed contents. This limits the amount of energy needed to bring lumber to the desired 6% to 8% moisture content. I use a Rockler steam generator. I dont think the same could be said for an old reefer truck converted into a kiln (no matter how well it dries lumber). The cost associated with shed construction was similar to buying a prefabricated kit. Solar kiln drying was most effective in the summer and early fall, when kiln efficiencies were 90% to 67%, respectively, and drying times were 2 to 3/one-half/ times faster than air drying.