Greenhouse Management
Glossary
U
ULTRAVIOLET RADIATION (UV) – Ultraviolet light is a type of electromagnetic radiation, as are radio waves, infrared radiation, X-rays and gamma-rays. UV light, which comes from the sun, is invisible to the human eye. It makes black-light posters glow, and is responsible for summer tans—and sunburns.
UNIT HEATER – Unit heaters consist of a finned coil and small propeller fan contained in a pre-designed unit. These units are available in either horizontal or vertical configurations and are generally hung from the greenhouse structure at roof level. Air is discharged either directly into the greenhouse or into a perforated plastic distribution tube (“poly tube”).
