Chapter 5

Greenhouse Energy Conservation Strategies

Managing Greenhouse Crops to Conserve Energy

Dynamic Temperature Control

In northern climates, high-energy inputs can be required to maintain a desirable greenhouse temperature, making fuel for heating one of the larger greenhouse production expenses. Greenhouse growers can reduce energy consumption by managing the greenhouse environment with dynamic temperature control (DTC) strategies. In DTC, heating set points are lowered during periods when the greenhouse energy-loss factor is high (for example, on a cold and cloudy day) and increased when the energy-loss factor is low (on a warm or sunny day).

Transplant Larger Plugs/Liners to Reduce Heating Costs

In the production of ornamentals, most growers produce crops in two distinct phases: the young plant (plug and liner) stage and the finish plant (transplant to flowering) stage.

Grow Cold-tolerant Crops

In the coldest regions of the country, some growers are growing more cold-tolerant crops such as lettuce, kale, bok choi, and other cold-loving vegetables, especially in the winter months, as a way in reducing energy costs.

Arrangement of Plants

For the most effective and uniform cooling and heating, the rows of plants should be arranged in the direction parallel with the ridge or gutters of the greenhouse structure. For ventilation, this assumes that the ventilation system (fans and air inlets) would be located on the end walls (perpendicular to the direction of the gutters).

Space Management

Plants can be consolidated to keep heated greenhouses full. The use of movable benches can achieve 90 percent floor coverage with plants.

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