Growers looking to high efficiency vent-free heaters for their greenhouse operation may be disappointed in their performance when growing ethylene sensitive crops like tomatoes.
Recently, a Pennsylvania grower sold on the high efficiency rating of a vent-free unit purchased and installed one in his tomato greenhouse. For those unfamiliar with these units they utilize a motorized fresh air inlet that transports fresh outside air into the unit to aid in the combustion of the propane or natural gas fuel.
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