The use of thermal screens for energy saving and greenhouse climate management in protected edible crop production – performance optimisation.

Trials undertaken over a three year period in a commercial tomato nursery showed that a modern design of thermal screen consistently delivered energy savings with no reduction in yield compared to an unscreened area.

• The average energy saving was 100kWh/m2 pa (13%).
• At current gas prices the energy saving is worth at least £2.00/m2 pa
• Acceptable humidity control can be achieved with thermal screens.
• No increase in botrytis levels was recorded.
• A greater focus on irrigation control is required when using a thermal screen.

Thermal screens create a different greenhouse environment to that normally experienced in an unscreened structure. These differences need to be fully understood and appropriate measures implemented if crop performance and energy savings are to be maximised.

Escalating energy costs, the Climate Change Levy (CCL), and increasing pressure to reduce the environmental impact of energy use mean that energy saving has become an important issue for all producers of protected crops. Screens (thermal, blackout and shade) are widely used in the