An automatic temperature control system, preferably computerized, should be included. Heating of the house should be done by unit gas heaters. Never tie the greenhouse heat to the school boiler room. Cooling is a must, and the best method of cooling involves a fan and pad system. A greenhouse can get much too hot for plants, even in April, May, June, September and October when school is in session.
Ventilation alone can cool a house during many times of the year.
Ventilation can be accomplished with vents and an air-jet system. Consider installing energy curtains that reduce heat loss at night during cold periods and keep plants cooler in the day during warm periods. Modern commercial greenhouses use energy curtains extensively. It is often useful to divide the greenhouse with a wall and to separate environmental controls so that one room can be kept at less than 60 degrees at night and the other above 60 degrees at night. This allows the students to work with plants requiring different conditions.