The Model A-1 Unit Heater is an enclosed flame heater that requires venting to the outside of the greenhouse. It also requires a fresh or combustible air intake from the outside of the greenhouse.

The A-1 is square in design - 16.25 inches wide, 17.5 inches deep and 25 inches tall, constructed of non-rusting mill polished aluminum outer shell, supporting a 24 gauge aluminized steel firebox with vertical flues for maximum air circulation with a stainless steel burner enclosed rated at 25,000 B.T.U. input. This heater must be vented with a 3 inch vent pipe for proper draft. Vent pipe not included (can be obtained locally).

Installation 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.

A 2" to 3" PVC air intake pipe should be installed as the figure shows. The outside elbow should be turn down to keep out water and screened to keep out rodents. Intake pipe can be offset to one side. It does not have to be in center of heater. The pipe extending outside must be no more than 12" vertically from inside floor grade, and should stop about three inches from the heater, and about four inches up from the floor.

Heating Capactiy and Ventilation 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. 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, we allow as much as 225 square feet to one unit. Do not over look the necessity of providing a way for fresh air to enter the greenhouse. This is a 'must' and should not be eliminated. Illustrations show the proper way to install the air intake pipe for the model A-1. A slight top ventilation is also necessary in the greenhouse to provide for circulation and exhaust. In case of heavy snows, take care not to let the vent pipe get buried as the heaters as the heaters need oxygen to burn properly.
Single Stage Thermostat Southern Burner heaters are equipped with millivolt controls and wall mounted thermostat that require no electricity for operation. Two styles are available: The first being a Single Stage Thermostat that has a temperature range of 45 to 75 degrees. When you select a temperature setting the heater will cycle on and off at this setting. Regardless of the time of day or night.

Set Back Thermostat The Second Style is a Day and Night Set-Back Thermostat. This gives you the capability of two separate temperatures, one for day and one for night. The thermostat has an adjustable clock that you can choose from 15 minute intervals to set the temperature change from day to night settings. The clock is powered by an "AA" Alkaline battery still giving you the convenience of no electricity. Temperature range is from 50 to 90 degrees. Mounting of the thermostat can be up to 25 feet from the heater and should be shielded form direct sunlight or water.

Safety All controls have a 100% safety cut-off feature. If the pilot flame should go out for any reason, the millivolt control would shut off all gas to the heater. Pilot flame would have to be re-established before heater would operate.