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).
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
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.
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.