1. 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

2. Convection Tube

3. Holes

5. 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

6. 4. Terms BTU (British Thermal Unit)
Heat required to raise 1 lb. of water 1oF
Used to measure and compare ability of heating systems