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Actual comparison on energy consumption on kilns in Europe (Denmark).

Company: Dansk Trae Emballage Ribe, Denmark.
Drying: 23mm pine boards used for pallet, crating and other packing solutions.
Background: The company operates five kilns. These kilns have been placed in two groups:

• Kilns with traditional roof type venting
• Kilns with heat recovery system.

Both groups have a KW meter on the heat supply provided as accurate heat usage measurements as possible. In addition, most lumber mills dry a great variety of species and thickness, which make comparison difficult. In this case, the company is drying only one specie and one thickness making for an accurate comparison.
Period of this comparison: January 4th to January 31st, 2001

TABLE 1: Raw numbers collected from Dansk Trae Emballage.
	cubic meter	KW usage	Kw/m3
Traditional kilns:	1380 m3	239120 Kw	173.28 Kw
Heat recovery kilns:	>567 m3	65580 Kw	115.66 Kw
Savings in percent:			33.3%

TABLE 2: Estimated savings per 1000 m3 lumber dried per month.
	cubic meter	Energy usage	US$/Kw	US$/month
Traditional kilns:	1000 m3	173275 kw	US$: 0.0536	US$: 9287.54
Heat recovery kilns:	1000 m3	115661 kw	US$: 0.0536	US$: 6199.43
Possible savings				US$: 3088.11

Note 1: Based on one liter of gas costing US$: 0.34 and a boiler
with 90% efficient. (No capital cost included).
The savings from our example are based on comparing older traditional type kilns with the newest technology in heat recovery. The savings in this example may not be obtainable in every situation, but we believe that savings between 15% to 40% is possible depending on your specific situation. We have been able to establish a rule of thumb:

• By upgrading existing kilns and installing a heat recovery systems, you will be able to increase you capacity by about 50% without increasing your heat consumption and boiler capacity.