It does not have to be in center of heater. A slight top ventilation is also necessary in the greenhouse to provide for circulation and exhaust. In areas where there is heavy snowfall, it is necessary to keep the ends of the air intake pipe open. This can be accomplished by tilting something over the outside opening while the snow is falling. Heating Capactiy Southern Burner heaters are designed to operate under the side benches, installed flush with the front edge of the growing bench or at the end of the isle.
Heaters are available for natural or propane gas.
In northern states, it is suggested that one unit be placed for every 150 to 175 square feet of floor space in a conventional greenhouse. In central states, place on unit heater to every 200 square feet of floor space. In the southern states, allow as much as 225 square feet to one unit. Single Stage Thermostat Southern Burner heaters are equipped with millivolt controls and wall mounted thermostat that require no electricity for operation. The first being a Single Stage Thermostat that has a temperature range of 35 to 75 degrees.