How does vacuum drying work?

Vacuum drying is based on the scientific fact that the boiling point of water is lowered when the atmospheric pressure is lowered. In effect, a VacDry kilns boils the water out of your lumber and releases it as water vapor. All in a highly controlled process.

In our kilns we not only evaporate water from the external surface but from the core as well. By performing this at low temperatures we minimize internal stresses, reducing the occurrence of surface checking and internal honeycomb. Defects and degrade are further minimized due to the fact that moisture removal under vacuum occurs mainly in the longitudinal direction of the wood in the form of steam.

In addition, because the process takes place in a shorter period of time at reduced oxygen concentrations, discoloration of your wood is negligible.

How much does this technology cost?

Always a tricky question to answer.

Our kilns cost anywhere from around $100,000 to almost $360,000. More when you add in material handling systems.

But, like all capital equipment, the price is only part of the overall answer. If I can purchase something for $100 that allows me to make $200 profit, it’s well worth it.

The same is true with our kilns. You need to look at your return on investment. What species are you planning to dry? Can you get premium pricing for your final product? How much extra do you realize by minimizing degrade? What about faster turnaround and reduced on site inventory? And with increasing energy costs, what’s the differential in operating costs when compared to conventional kiln drying?

The bottom line: Initial cost is only part of the equation. You need to examine a variety of factors to find the true cost/profit potential.

How do I know a VacDry kiln will work for me?

At VacDry, we realize “the proof is in the pudding.” Which is why we offer all our potential customers the opportunity to send us a load of their lumber for us to dry at our research and development facility in Jersey Shore, PA. To find out more get in touch with any of our sales team. You can access them by clicking on the contact button.

Will a VacDry kiln take the place of my conventional kiln?

Not necessarily. In fact, at VacDry we believe conventional drying techniques have their place, especially where for situations where you have a high volume of very easy to dry wood.

Instead, we think the VacDry technology is perfect for the operator who places a premium on quality. In addition, a VacDry kiln has the capability to dry thicknesses not feasible with conventional drying methods, like 4” Cherry squares or 3 1/2” Red Oak. Also,if you have customers who look for fast delivery times and you don’t want to tie your yard up with excess inventory, then a VacDry kiln is for you.

So don’t go knocking down your present kiln. Instead consider adding on a VacDry to your existing operation.

You say a VacDry kiln uses less energy. How does that work?

In a couple of different ways. True, the energy needed to vaporize the water in the wood is the same regardless of how you dry it. But, because the kiln chamber is sealed, practically all the energy inside the kiln is used to heat the wood and not lost through conduction and convection. It’s essentially more efficient. Add to that our shorter schedules and it’s easy to see why VacDry kilns save energy.

With all this advanced technology, aren’t VacDry kilns hard to operate?

No. In fact, we have gone out of our way, through software development and use of PLC’s, to make our kilns extremely easy to operate. Granted, whoever runs the kiln needs some training, but it’s not rocket science. With easy-to-follow instructions and visual screens, VacDry kilns are remarkably simple to set up and run. Plus, our research and development center can monitor your settings and schedules over an internet connection or standard phone lines.

How come there is no pre-drying of the wood?

Generally speaking for two reasons. First, green wood simply works better. With green wood, there’s less chance of damage occurring in the yard or while air drying. Secondly, it’s more economical. The faster you can get your wood from the forest to your customer the more profitable it is for you.

There are some instances where we suggest predrying in a predryer, like heavily occluded species that demand a longer, gentler drying time.

What thickness of wood can I dry in your kilns?

Anything from veneer to 10” squares or larger. Because VacDry kilns facilitate moisture removal under the surface of the wood, we’re able to dry loads like 4” cherry squares in a matter of weeks.

I’m planning on drying imported exotics, do you have schedule for that?

Maybe. We’ve established schedules for many exotic species. When confronted with something we’ve never had the opportunity to dry, we work with you to develop the proper schedule that’s most economical for your use.

What type of throughput can I expect?

That, naturally, depends on what you’re planning to dry. As an example, our smallest kiln, the Model 1.25, can dry over 100,000 BF of 4/4 Red Oak per year. In comparison, a 1200 BF DH or conventional kiln can only output 12,000 BF per year. So if you compare apples to apples, a VacDry kiln can produce 8X as much in the same amount of time.