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Heater Output Range
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| The output range is measured in thousands (K)
of BTUs. This is the measure of heat output from a heater. To determine how much
heat is needed for a greenhouse, you can use our Greenhouse
Heater BTU Calculator. |
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Heater Mounting Types
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Wall
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Wall mounted heaters are attached directly to
a wall and vent through the wall to the outside of the structure. They do not
take up much floor space, but the area in front of them should be free of obstructions. |
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Floor
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These heaters require no mounting. They have feet
and can be placed directly on the floor. They take up the most floor space but
can be placed under a bench to minimize that. |
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Hanging
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Hanging heaters are generally mounted directly
to or hung from the ceiling. They use the least amount of floor space as long
as the heater can be hung high enough to not be in the way. |
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Heater Combustion Types
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Open
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This heater uses inside air for combustion. It
is fine for areas that do not have contaminants in the air that can damage the
heater. The burner is not sealed inside the heater so flammable liquids should
not be placed close to the heater. |
Sealed/
Separated
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This gas heater uses outside air for combustion
which is better for areas that have a lot of contaminants in the air like wood
shops. The burner is sealed inside the heater so all of the air used for combustion
is brought in from outside the structure. This type of heater has an intake and
exhaust pipe (either separate or one inside the other) which is run to the outside
of the structure. |
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Heater Vent Types
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Unvented
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Unvented gas heaters are not vented to the outside.
Gases produced from combustion are released directly into the heated area. This
type of gas heater is only recommended for temporary use in a greenhouse because
many plants are very sensitive to the by products. |
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Gravity
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These gas heaters require vertical venting because
the exhaust must rise through the vent pipe and is expelled outside. They are
dependent on natural drafts to move the exhaust through the vent pipe. Outside
air must be brought into the structure to replace the exhausted air. |
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Power
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Power vented heaters are equipped with a blower
that pushes the exhaust air through the vent pipe and outside of the structure.
Most power vented heaters can be vented vertically or horizontally and use smaller
vent pipes than similar size gravity vented heaters increasing their efficiency.
Outside air must be brought into the structure to replace the exhausted air. |
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Direct
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Direct venting is unique to sealed combustion
heaters. It uses 2 pipes (ususally one pipe placed inside the other) to provide
the heater with both an inlet and exhaust. When heated exhaust air leaves the
vent pipe, it automatically pulls in the same amount of outside air in exchange
for combustion. The outside air is also heated as it passes over the exhaust pipe
and into the combustion chamber. No additional outside air must be brought into
the structure to replace the exhausted air. This system can be gravity or power
vented. |