2. Unit Heaters A.K.A. LOCALIZED Used for smaller greenhouses Convection heat- to heat the air Distribute heat by fans or convention tubes Most burn natural gas Modine Heater is a common brand Can operate independently
Convection Tube
Holes
3. Radiant Heaters AKA- Infrared Heater Infrared Heat Lamp creates heat Radiant Heat: IR warms surfaces (plants, benches, sidewalks, soil) The warm surfaces in turn warms the air The air is not directly heated Heaters are overhead 20 to 30 feet apart Fueled on gas or electricity
4. Terms BTU (British Thermal Unit) Heat required to raise 1 lb. of water 1oF Used to measure and compare ability of heating systems