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Comparison of dehumidification and heat and vent drying of hem-fir softwood

Abstract

The objective of this project was to demonstrate the performance of dehumidifier kilns, compared to gas-fired, hot-air kilns in drying a commercial grade of softwood lumber. To accomplish this, drying tests were conducted with matched loads of lumber in a new test facility which was constructed to operate as a conventional heat and vent kiln or as a dehumidifier kiln. Comparisons were made of drying times, shrinkage and quality of dried product and total drying energy consumptions. Data from these tests were used in conjunction with capital, energy and other costs obtained from suppliers and operators of existing kilns to make economic comparisons between commercial-sized dehumidifier and heat and vent kilns. These comparisons were made on the basis of equivalent uniform annual costs. Dehumidification drying took about 20% longer and used about 50% of energy compared to heat and vent drying. Analysis of the test runs indicated that further improvements in the energy utilization efficiencies of dehumidifier kilns are feasible since one run indicated an energy consumption of only 36% of that in heat and vent drying. No differences in shrinkage or degrade were apparent. Economic comparisons for three sizes of kilns showed total drying costs by dehumidification to be  More>>
Publication Date:
Mar 01, 1988
Product Type:
Technical Report
Report Number:
CEA-418U461; CE-03247
Reference Number:
CANM-90-007095; EDB-90-178343
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; KILNS; PERFORMANCE; WOOD; DEHUMIDIFICATION; DRYING; ECONOMIC ANALYSIS; ENERGY CONSUMPTION; ENERGY EFFICIENCY; FIELD TESTS; SENSITIVITY ANALYSIS; ECONOMICS; EFFICIENCY; TESTING; 320303* - Energy Conservation, Consumption, & Utilization- Industrial & Agricultural Processes- Equipment & Processes
OSTI ID:
6488490
Research Organizations:
Forintek Canada Corp., Vancouver, BC (Canada). Western Forest Products Lab.
Country of Origin:
Canada
Language:
English
Availability:
Canadian Electrical Association, One Westmount Square, Suite 500, Montreal, PQ, CAN H3Z 2P9.
Submitting Site:
CANM
Size:
Pages: (vp.)
Announcement Date:
May 13, 2001

Citation Formats

Mackay, J F.G., and Nielson, R W. Comparison of dehumidification and heat and vent drying of hem-fir softwood. Canada: N. p., 1988. Web.
Mackay, J F.G., & Nielson, R W. Comparison of dehumidification and heat and vent drying of hem-fir softwood. Canada.
Mackay, J F.G., and Nielson, R W. 1988. "Comparison of dehumidification and heat and vent drying of hem-fir softwood." Canada.
@misc{etde_6488490,
title = {Comparison of dehumidification and heat and vent drying of hem-fir softwood}
author = {Mackay, J F.G., and Nielson, R W}
abstractNote = {The objective of this project was to demonstrate the performance of dehumidifier kilns, compared to gas-fired, hot-air kilns in drying a commercial grade of softwood lumber. To accomplish this, drying tests were conducted with matched loads of lumber in a new test facility which was constructed to operate as a conventional heat and vent kiln or as a dehumidifier kiln. Comparisons were made of drying times, shrinkage and quality of dried product and total drying energy consumptions. Data from these tests were used in conjunction with capital, energy and other costs obtained from suppliers and operators of existing kilns to make economic comparisons between commercial-sized dehumidifier and heat and vent kilns. These comparisons were made on the basis of equivalent uniform annual costs. Dehumidification drying took about 20% longer and used about 50% of energy compared to heat and vent drying. Analysis of the test runs indicated that further improvements in the energy utilization efficiencies of dehumidifier kilns are feasible since one run indicated an energy consumption of only 36% of that in heat and vent drying. No differences in shrinkage or degrade were apparent. Economic comparisons for three sizes of kilns showed total drying costs by dehumidification to be less for a small-size kiln but more for medium- and large-size operations. Sensitivity analyses were performed to observe the effect of alternate energy prices, dehumidifier energy consumptions, dehumidifier drying times, building costs and degrade. 9 refs., 7 figs., 36 tabs.}
place = {Canada}
year = {1988}
month = {Mar}
}