Production models of the GARN WHS 1500 and GARN WHS 2000 units were tested by Intertek, an independent test laboratory, in accordance with the Thermal Storage Appendix X1 of ASTM Document E 2618 – 09.

Emissions and Efficiency Results:


GARN® WHS 1500

GARN® WHS 2000




Emissions Output

0.131 lbs/mmbtu

0.088 lbs/mmbtu

Emissions Rate

2.87 grams/hr

1.65 grams/hr

Official Report

Click Here

Click Here


* The LHV values have been used in the Federal Rebate Program. To compare to non-wood heating equipment, the HHV efficiency should be used (66.9% – 70.2% HHV delivered efficiency).

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