IMPLICATIONS

Rather than following conventional wisdom of storing surplus solar energy in hot water or other storage systems, we simply use it when it is available and in some cases store surplus in the kiln charge itself by virtue of some unique and patented control system features. Had we not come to our high levels of understanding, the vastly superior heat generation from our solar drying technology would be wasted.

Armed with knowledge that the cyclic process produces superior quality outcomes, our control system concentrates drying into daylight hours when energy is available.

It costs less to vent and re-heat warmer daytime air. By operating the kiln cooler at night when the air is coldest, insulation losses and associated costs are minimized. By avoiding heat storage devices, we avoid the physical cost AND the substantial energy losses associated with the extra four levels of heat exchange loss that one other solar hybrid kiln technology experiences; for example, exchanging light energy to heated air then to hot water and from hot water back to air inside the kiln. By eliminating these significant waste factors, our technology stands head and shoulders above others, despite one particular manufacturer’s false claim to the status of “easily the most efficient kiln in the world”.

To further emphasize the practicality of our cyclic principles, it is worth knowing it is possible to dry hardwood to the same extent in 8 hours of cyclic drying at 40degc as a fixed schedule 2.7 degrees cooler applied for a full 24 hour period!

As suggested earlier, we have found that moisture distribution, in particular differential case-core moisture is of considerably greater importance to quality outcome (collapse etc) than overall drying rate over short time frames. Nature has been telling us this in air seasoning operations since long before my company began to refine the process. We have also found that cyclic drying may, subject to specific conditions being met, be conducted with faster process times than conventional application of stepped conditions that remain relatively constant within each step.

To illustrate this, our control system, schedules and general policy deliberately allows mc loss to exceed the average process target dry rate by as much as 200% on the best solar days within a weather pattern. During the worst days, we provide an opportunity for the product to relax so that it is ready for, and capable of withstanding the next peak day of drying. Meantime, other misguided souls are busy paying the banker for their heat storage devices, accepting that 30% heat exchange losses are necessary and under-performing as a result. In any case, their control systems are incapable of facilitating this as are our patented innovations.

Additionally, by using the natural moisture extractives from the timber to more effectively re-saturate the outer case from within AT THE SAME TIME as externally by using the naturally increasing kiln humidity to the same effect, high cost, sophisticated, energy consuming humidification systems may be avoided; at the same time, improved wood stress conditions lift constraints that in current normal practice limit capacity to deliver extra heat during a daily drying (“D”) phase to maximize temperature diffusion and overall drying rate.

The above outcomes cannot simply be achieved or optimized without our exceptional control system and our numerous departures from normal practice; something that I have personally done for most of my working life.

There are a litany of past clients who simply could not be convinced to practice cyclic drying, whose early technology made it difficult to adopt, and who in effect operated their solar kilns like conventional kilns....BAD POLICY with inevitably mediocre outcomes! Our advanced control systems are ready for the task, incorporating multiple practical and patented features that allow for reliable, positive outcomes every time, on any species and in any environment or seasonal condition. Most importantly, with limited skills.

Another significant effect of our increased knowledge and understanding is that we no longer routinely apply the same conventional drying schedule limits as we once did. Long ago, we found that by doing so, we sacrificed valuable drying time and solar energy by wasting peak energy and accepting that we could emulate conventional times only on the best days or by adding costly supplementary energy. Our knowledge and results are brought about by vastly improved energy management. Having said this, our highly developed prescription and “limits” differ only marginally from convention and could hardly be described as extreme in any case.

This technology has been designed to be used as a retrofit to commonly used inferior kiln technologies or as part of a “solarola” kiln package capable of producing comparative advantages that our competitors cannot hope to emulate.

In some cases, in particular for higher value products we may be prepared to perform our contract drying for little or nothing if you are prepared to contractually concede to pay us an amount equal to the value advantages that we can deliver.

If the common sense outcomes from our more natural drying prescription and technology don’t make simple good sense to you, call me and I will help you further understand.

OTHER OBSERVATIONS

The universal perception and belief that drying rate and kiln conditions must be maintained at tightly regulated levels at all times in order to produce high quality outcomes is true for conventional drying. It is, however a myth unless inferior conventional drying practice is being applied. Our own commercial operations have routinely achieved similar drying rates to conventional drying practice with better quality results when 100% of our target drying rate occurred during the day. In numerous instances, successful quality outcomes have been achieved for sensitive species and products when individual daily (cyclic) drying rates were as much as 2.5 times higher than conventional drying rates. Most importantly, this level of deviation achieved full process drying rates and quality outcomes similar or better than conventional drying outcomes.

Armed with two methods of case moisture control (internal and external) and some unique patented control system elements, our method and technology avoids the need for expensive artificial energy-consuming steam and other external humidification systems vitally required and used by conventional prescription operators.

Providing a clue as to one reason why this knowledge is useful, using our advanced prescription it is possible at this stage to produce improved quality while safely achieving as much drying in 8 hours at 40degc as a conventional kiln at 37.6 degrees in 24 hours. It is considerably less expensive and more practical to maintain 40 degrees for 8 sunlit hours of each day to achieve a 24-hour target drying rate then “rest until the next day than it is to maintain 37.6 deg all day and night! When you have Solarola technology capable of generating more heat than inferior solar kilns, this really factors into our superior technology status.

Cyclic Drying And Energy Management

Having established that drying by day and cooling by night produces improved quality outcomes, it makes additionally simple good sense to dry faster during the day than at night for many other reasons.

• Reduced energy consumption for vented air reheating during warmer daylight hours in lieu of during cold nights.
   

• Reduced insulation losses at night from a kiln operating at lower temperatures when air is coldest.
   

• Eliminates the ridiculous concept of using expensive water or heat storage devices to maintain drying at high levels through the night period, for no good reason.
   

• Eliminates the high heat-exchange energy losses inherent to ALL heat storage concepts provided by others to facilitate their misguided attempts to dry evenly at night and for every minute of a 24 hour period.

Because our dual method of cyclic case re-saturation is so successful, lumber stock begins its daily drying cycle in a state that allows us to expose most timber species to higher-than-normal levels of heat energy to maximize temperature diffusion beyond levels that “normal” prescriptions are capable of.

This means that we are able to productively USE the considerably greater levels of energy that our technology is capable of generating during daylight hours whereas alternative solar and hybrid technologies that typically produce less energy than ours are obliged, by operating prescription to waste.

Our past three years and substantial funds have been devoted to secret developmental work that has increased our highly developed understanding of cyclic drying principles. This work in turn has led us to develop and patent a novel and outstanding, high-tech control system that is capable of optimizing the cyclic prescription and to revolutionize the low-medium temperature lumber drying process. Elements of our advanced control system will allow us to safely push drying rate boundaries further than before.

Combined with our vastly improved drying system and its greatly enhanced solar collection and insulation properties, this prescription has combined to make our technology an undeniable and compelling option for your future. Simply put, no controlled mass-drying technology can emulate our cost and quality capability. In many cases, a very small quality-yield value advantage can be worth multiple times the total process cost!
 

Those who have purchased our earlier model kilns and who have, against our advice elected to adopt conventional drying prescriptions may now have a better understanding as to why their early model solar kilns have not performed to the same level as others including our own.

Drying Rates (Time)

Until recently, we have maintained a policy of constraint in terms of drying rate. After periods of high drying rate we have altered schedules to “put the brakes on” to achieve similar net process drying times as conventional full-schedule drying rates. We now know that we have been ultra conservative and that our sophisticated control system will soon allow us to routinely, reliably and safely exceed normal rates achieved by the lumber industry in general.

We expect that the substantial speed advantage experienced by the 1992 research will be considerably improved at the same time as increasing dry product value and reducing cost of the kd process markedly.
The system we have developed has implications for, and may be made available for retrofits to conventional box type drying technologies.

Summary

By innovatively adapting the drying prescription to suit the natural weather and diurnal energy cycles we have made the best available solar-hybrid drying system the best in the world. By developing cyclic drying and the need for heat storage devices, the use of which makes those who use them and who waste a high percentage of the energy in the exchange process look very silly indeed. Our combined package of superior technology and unique prescription make ours a stand-out system for lumber drying almost anywhere and for any specie in the world.

Greg Weir