Kiln Dried Lumber and Firewood Using Global Container Kiln


Global Energy Container Kiln Topics

Common Lumber and Firewood Dry Kiln Questions

The Most Commonly Asked Questions About The Global Container Kiln

1. What is a dry kiln and how does a conventional kiln work?

Conventional dry kilns have been in existence for over 50 years now. The basic concept is to dry wood products using airflow, humidity control and moisture extraction. Fans evenly distribute the heat which extracts moisture and the vents allow the humid air to be removed from the kiln. A simple controller constantly monitors and adjusts the heat and venting to maintain proper humidity in the kiln for accurate drying. Over a given period the temperature is raised and humidity reduced until a desired moisture content is reached.

2. Why is a dry kiln important to my operation?

A kiln can give you a door to value-added profits. Custom drying and filling customer orders in a timely manner enhance customer satisfaction and reduce inventory cost (especially costs associate with delays in drying from larger mills). Selling KD (kiln dried) lumber gives you access to $200-$1,000 per thousand board feet value added. Selling KD lumber gives you better market access versus selling green or air-dried lumber. Customers perceive the KD stamp as one of quality and a stable product.

3. Why not use custom dry kilns from other larger mills?

Trucking your green lumber to a larger mill costs time and money. First, a larger mill may not schedule your lumber to be dried until space if available. Second, a larger mill may have such large dryers that they will mix your specie of hardwood with others, thereby compromising the quality of drying (a kiln chamber can follow only one schedule). Third, many green mill operators are concerned that large custom kiln drying operations may not handle their bundles with as much care. Probably the most critical factor now is the severe overtaxing of current kiln space. In most parts of the country there is simply no room for custom drying and many larger mills are no longer offering its kilns for the use of green mills.

4. What must be done daily to run the kiln?

Since the operation is automatically controlled by the industrial Controller there are only three basic checks every day.

(1) Make sure the equipment is operational.

(2) Check the moisture content of the wood with the included Moisture Meter.

(3) When a desired moisture content is reached, change the set point on the controller [this is done 4-6 times during a given schedule].

5. How is the kiln different from other kilns?

Global received a great deal of help and advice when it designed this kiln. It is in all means, a conventional dry kiln. The basic concept was to provide an affordable kiln which was easy to operate and simple enough to be put together by the buyer. There is nothing new about this kiln except that the kiln chamber is a aluminum shipping container or insulated refrigerated van. Vince Schneider who has built hundreds of kilns assisted with the design and made the blueprints. Since all of the parts are off-the-shelf there are no custom components to service or replace, saving on initial and replacement costs.

The basic design also keeps down maintenance costs. Since the kiln is put together by the buyer, he has a good knowledge where everything is and how it works within the kiln.

With more than 40 kilns sold and in operation, we have a long history of experience with these kilns.

6. What about DH kilns and why is there such a high kiln turnover sales rate?

DH or dehumidification kilns are initially less expensive to purchase, but have higher operational costs. The advantages of a lower acquisition cost is soon diminished from the high monthly electrical bills. Many DH buyers switch to conventional dry kilns as soon as they start paying the high utility bills and maintenance bills. As you look through the classified/want-ads under kilns you will notice a very high

proportion are DH Kilns. In addition, most DH kilns cannot set pitch or heat treat since they are very low temperature kilns. Many DH kilns have supplemental heat sources, which essentially make them a conventional kiln.

7. As far as operational costs, what can a kiln operator expect to pay for electricity and heat (hardwoods and softwoods)?

Typically for conventional hardwood kilns you can expect to pay about $15 per 1,000 BF on the electrical side (for the fans) and about $15 per 1,000 BF for the heat (depends on the price of natural gas or propane). You can save 15-30% of the fan electrical costs by turning off some fans near the end of the hardwood drying schedule since the wood does not require as much airflow. For SYP and other softwoods you can expect about $3-6 per day for the fans and about $3-8+ per day for heating costs depending on the current price of natural gas.

8. Why is the Global Kiln Kit a better value?

The Global Kiln is a better value because it is a time proven kiln which you, the buyer, can put together using simple hand tools. In addition it uses a fully portable shipping container as the kiln chamber which can be moved or sold without any modifications. The shipping container is self-supporting and does not require a foundation. It is also wind/watertight. The savings in labor, foundation and standardized off-the-shelf equipment result in large savings for both acquisition and maintenance costs.

9. Are there other kilns of this type or size?

There are other portable dry kilns of this size. The container kiln is the most copied kiln in the industry, especially with DIY. Nyle has a similar kiln. Koetter Dry Kiln has kilns from 400-4,000 BF with a foundation and uses a method of drying called constant venting. Constant venting is a method which is always venting and costs more per BF to operate because of the heat loss. Since the temperature never gets above 140 degrees F, the schedule is also a bit slower. While drying hardwoods this is not a big concern but with softwoods, such as Pine, the difference becomes greater. The smaller Koetter kilns use air-over motors which are more likely to receive heat/moisture damage than TEFC (Totally Enclosed Fan Cooled) motors which are used in the Global Kiln. In addition, the motor insulation in the Global kilns are rated above 200 deg. F.

10. Can I use my wood waste to provide heat for the kiln?

Yes. Using a Waterstove (like the Central Boiler) or solid fuel burner, you can use your scrap wood to heat water which is then routed to the kiln where the heat is extracted by the use of a hot water to air heat exchanger (radiator). Not only will this save you on fuel costs but may actually save you money from the cost of disposing of your wood wastes. The Waterstove is a hand-fired unit which requires loading 3 to 4 times per day. The Log Boiler offers an even better solution by accepting large format wood waste including logs, stumps, pallets, etc. The issue of a wood waste fired system versus a natural gas or propane heating system is one of convenience. The natural gas / propane system is fully automatic.

11. Do you offer an alternative to the Wet Bulb sensor?

Yes. We offer a solid state humidity probe which does not require a wet bulb well (container of water) to operate. The probe operates in conjunction with a Watlow or other digital controller which is sent in place of the standard controller. This is an expensive alternative, and best for larger kiln operations.

12. Do you offer alternative heating systems?

Yes, we offer two other heating systems for the kiln:

(a) Cogeneration: Using a Log Boiler and a Infinity Turbine (waste heat to power), you can produce electricity and pure hot air which is introduced directly into the kiln. Excess electricity can be used by your mill equipment. For more information, please visit our Infinity Turbine site.

(b) Heat Pipe Kiln: A large diameter pipe (10-30 inches) is used as the heat exchanger. It is installed just below the ceiling where the airflow can circulate around it. At one end of the steel heat pipe is a natural gas gun, or other heating direct fired device such as a solid fuel burner.

Process of Kiln Drying Firewood – Questions/Answers:


Wood is loaded (randomly) into wire baskets and then put into the kiln chamber. If you own a firewood processor, you can convey the wood right into the baskets and then forklift them into the container kiln, or load them onto a rail system for further rolling into the kiln chamber.

Kiln Drying

Chamber is heated and fans circulate hot air around firewood in baskets. Vents exhaust moist air out. The more heat and faster airflow, the better the firewood dries (and faster it dries).


The most value added for firewood processing is in the kiln drying and packaging. Packaged wood sells for 2-3 times more per unit volume, but only costs slightly more to package and deliver.

Best Strategy

The firewood dealers that make the most profit have their wood split by other processors. They have the wood split and delivered to their kiln and packaging operation, where the wood is dried, packaged and then distributed. The other benefits are less workman’s comp and insurance.


Global can assist you in marketing your firewood. We highly recommend a classified ad, yellow pages ad, Google ad, postcards, and word of mouth. A satisfied customer is your best form of advertising – keep them happy and they’ll rave about your product, generating additional sales. Provide a good quality, dry product, and have a good sales/delivery service and you’ll have a loyal customer base for years to come.

Question and Answer:

How do I know when the firewood is done ? We have two three proprietary methods to insure your firewood is dry. They are simple methods that will give you a standardized dry product.

Do I install the parts ? Yes, the kit is a do-it-yourself project. You may also wish to contract a plumber or electrician to install more technical items, and to be sure your project is to local code.

How is the kit shipped and when will it arrive ? After the final payment is made, the kit is drop-shipped from the parts distributors/manufacturers via UPS groundtrack. The entire process, from receipt of payment, takes about a week or two. Ordering boilers can take up to 3-4 months during peak season. It is best to plan ahead.

What is included in the kit and what does the buyer need to supply ? The kit includes all major components within the kiln chamber, such as fans, motors, venturies, vents, heating coils, controllers, water circulation pump, etc.

How is the firewood loaded into the kiln chamber ? If you have a hi-cube shipping container, or a insulated van, you can forklift in the baskets of firewood. Otherwise, you can install a simple track system and put the baskets on kiln carts. It’s important to have a material handling system for your firewood business, and this is just part of that overall system.

Do you recommend a shipping container or insulated van ? You can use any number of structures for the kiln chamber, even building one out of plywood or using a pre-fab metal building. The most expedient way to put together a firewood kiln is using a over-the-road insulated trailer (sometimes referred to as a reefer trailer). Used they are about $3-4,000 however they are already insulated and usually will have a higher clearance on the inside. Always choose a 9 ft 6 in height if possible. The 8 ft. high containers and vans don’t give much room for the interior fan rack. Even though the vans have wheels, you can simply knock them off so that the van lies flat on the ground.

What do you recommend for insulation ? If you purchase a container that is not insulated, you’ll need to insulate it with rigid foam, foil sided insulation (Thermax or similar brand names), that is a total of 2 inches thick. That amounts to about a R-14 which is sufficient. You do not need to insulate underneath the container or van. Always put in a vapor barrier if you plan to install the insulation yourself, and then have a top layer of 1/2 to 3/4 inch plywood to protect the insulation. Insulated vans sometimes have stainless steel interiors which are perfect for kilns. If you do install the insulation, vapor barrier and plywood, paint the plywood white so you can see inside of your kiln.

What are kiln baskets, and how are they made ? Kiln baskets usually measure 3x3x3 feet, but can be made to any dimensions, as long as they conform to your materials handling system to move the firewood around. To save money, weld these together yourself with angle iron (steel) and wire mesh (strong fencing material). We had one customer who actually thought about converting hog trailers to huge firewood holding pens and driving the entire trailer into a firewood kiln. As long as you can easily handle the basket, and it allows the heat and airflow to penetrate to the firewood, anything goes.

What temperatures does the kiln operation ? The kiln will operate up to 180 deg F. This is somewhat dependent on your heat source. Some waterstoves cannot get above 160 deg. F. Remember that the firewood needs alot of heat and airflow to dry.

Why do I need your kit and services – why can’t I just put this together myself ? We have experience in kiln design and operation. Just having a van, with a fan, and a heat source won’t dry your firewood professionally. We specialize in drying wood fast, efficiently, and to an optimal dryness to produce a superior product that your customer can trust (to burn clean, without insects, and uniformly dry).

I’ve seen other kiln sales groups out there with containers – are they copying your idea ? Yes, they are. But they probably don’t work quite as well and they certainly don’t have the experience (in both firewood processing and marketing) that we do.

Speaking of which – why do I care if you know how to sell firewood, all I want is a kiln ? It’s one thing to produce a premium product, but it’s another to market and sell that product. We have experience in both. Sometimes we can even provide you with buyer leads if you produce packaged firewood. We get calls from distributors all over the East Coast inquiring about quality kiln dried firewood.

What if I need assistance before, during and after fabrication ? Global provides unlimited consultation at any stage of your kiln project, after we are in receipt of an order.

Is there an official stamp for kiln dried firewood ? There is no official stamp for kiln dried firewood. I recommend you insert a pamphlet with your firewood delivery that signifies that it is KD. You could also brand the wood with a KD stamp on the end of the firewood.

How do you store the firewood after it is kiln dried, and how do you package it ? After kiln drying, keep under cover so that it does not come into contact with rain. Your best option is to package firewood by shrinkwrapping in two sizes (a) between .7-1 cubic foot, and (2) 4 cubic feet vertical. There are several reasons for this packaging –

first, you can sell to convenience stores and customers who don’t want a face cord or full cord, second, you can charge more for the smaller packaging, and third, the larger 4 cubic feet can by moved via dolly for larger house or condo use.

Do firewood buyers know about kiln dried firewood ? Kiln dried firewood is not well known yet, but customers love it. It’s guaranteed dry – unlike seasoned wood that is often still wet or green. People are willing to pay more for a consistently dry product. It’s heat treated, so there are no insects. It also does not produce as much creosote as season wood does.

What is the market for kiln dried firewood ? The market is definitely for the middle to upper class. You can do advertising directly to those customers via Google or Craigslist.com

Who do I market my premium kiln dried firewood to ? Market to a variety of groups, including, but not limited to condo/home owners, campgrounds, wood fired oven restaurants, and even retailers such as convenience stores. Focus on heat treated and insect-free firewood.

Global Energy Container Kiln Topics

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