Greenhouse Unit Heaters Redefined
The revolutionary tubular heat exchanger inside the Lennox LF-24 series of greenhouse heaters ensures you years of performance and high efficiency. Combustion is precise because of special "in-shot" burners and fan assisted exhaust. Equipped with a TrueLeaf Combustion Air Separator, it's bullet-proof.

Take this challenge!

Heating Efficiency Calculator

What is your greenhouse efficiency?

Take this simple challenge to find out where you are. Just answer the following questions to see how efficient your greenhouse is.

Please note that this is a rough gauge of how efficient a greenhouse is looking at only a few parameters.

What is your total greenhouse production area?


Area to be tested?


Type of fuel that you use:
Oil Natural Gas Propane

Average cost of gallon or therm?


Tell us the type of system you have:
Boiler System
Unit Heater