Heating & Cooling
Heaters: Heaters can come in gas or electric models and they are important because they maintain a uniform temperature throughout the greenhouse even in the harsh winter seasons in order to maintain year round plant production. They should in a centralized location, away from any flow of water, usually positioned above plants to avoid foliage damage.
Thermostat: Thermostats save money on fuel costs, improve crop production and all you to monitor a healthier, more comfortable environment for plants. Thermostats provide precise control of heating, cooling and ventilation systems. They are usually located at plant height near the center of the greenhouse where they are not influenced by drafts or sidewall cooling. It is best if both heating and cooling thermostats are located together and protected from direct contact with water and sunlight.
Exhaust Fans: These fans remove and refresh stale air with clean outside air o to allow plants to carry out normal functions of growth (photosynthesis and respiration). These fans reduce heat stress on workers as well as plants. They should be evenly spaced along the sidewalls depending on the size of the greenhouse.
Circulation Fans: These fans keep the greenhouse cool and keep the air circulating through the greenhouse to keep the environment cool during the heat of the summer. They should be located near the center of the air mass they are adding energy to. If used in a greenhouse with benches they should be placed above the foliage to prevent damage or growth deformities.
Evaporative Cooling System: This system reduces air temperature by evaporation of water into the air. As water evaporates, energy is lost from the air. Removing energy from the air lowers the temperature of the air being introduced into the greenhouse. These are usually made of cardboard and should be replaced every few years. They should be located along the length of one wall of the greenhouse, preferably away from the door, about 3-4 feet above ground.
Shade Cloth: A shade cloth is placed over a greenhouse roof to reduce sun penetration on plants and workers. They can be made of a variety of materials but it is important they don't rot, mildew or become brittle. they are generally located on the roof of greenhouses but sometimes extend to cover the side walls as well.
Horizontal Fans: These fans have a similar function to the circulation fans,to keep the air inside the greenhouse moving. They are used to eliminate air stratification and avoid the formation of hot and cold spots. They can be attached to near the top of sidewalls or just above benches to reduce air stress on plants.
Natural Ventilation: This a low
cost alternative for greenhouses in a moderate climate region. During warm weather, the temperature inside the greenhouse can be maintained with a degree or two of the outside temperature with little to no energy needed. The location of the ventilation can be open roofs or roll-up side walls.
cost alternative for greenhouses in a moderate climate region. During warm weather, the temperature inside the greenhouse can be maintained with a degree or two of the outside temperature with little to no energy needed. The location of the ventilation can be open roofs or roll-up side walls.