Temperature and radiation distribution in an infrared-heated greenhouse with a polyethylene cover

The environment produced by an infrared-heating system was compared to environments produced by two different forced-air heating systems. Three identical, polyethylene-covered and free-standing greenhouses were used, one for each heating system. With the air temperature set point 3°C lower in the infrared-heated greenhouse, leaf temperatures in all three houses were comparable. Horizontal and vertical air temp erature gradients were smaller in the infrared-heated house than in the two-forced air heated houses. The use of air recirculation improved air temperature uniformity in the infrared-heated greenhouse. Even under cold outside conditions (—12°C), the infrared system was capable of maintaining an adequate environment for plant growth and yield of a tomato-crop was similar between the three houses.