tips & tricks
This allows them to control the speed of
the fans and, therefore, the rate at which
the outside air is brought in. Put another
way, the grower can reduce the amount
of air the fans intake during cooler
weather and increase the amount of air
during warmer weather.
AIR-COOLED REFLECTORS
Ventilation systems with air-cooled
reflectors may need to be altered for
the winter months. Many growers can
reduce or eliminate the amount of time
the lights are actively air cooled. Some
growers take advantage of the cooler
air being drawn through the reflectors
and install additional reflectors during
the winter months. Increasing the
number of light fixtures is a great way
for a grower to capitalize on the winter
air coming through a ventilation
system. More light fixtures equate to
more heat, but they also equate to
higher yields. When the opportunity
arises to add light energy without
exceeding the desired operating
temperature, a grower can, and should,
seize that opportunity.
HEATERS
Growers with ventilation systems that
do not include air conditioning units
with heat pumps may need to add a
heat source to the indoor garden in
winter. This is especially true during
the dark cycle when the heat emitted
from artificial lighting is no longer
84
grow cycle
warming the garden environment.
Propane or electric heaters are
often used by indoor growers. Keep
in mind that propane or any fuel-
burning heater will emit carbon
monoxide and other byproducts that
can become a concern in a small,
enclosed area. Generally speaking,
fuel-burning heaters are best used in
large indoor gardens or greenhouses.
Many hobbyist growers instead
rely on electric heaters to maintain
warmer temperatures during the dark
cycle in the winter months.
MINI SPLIT AIR CONDITIONERS
AND HEAT PUMPS
More sophisticated growrooms may
be equipped with mini split air
conditioners with heat pumps. These
systems are rated according to the
outdoor temperature range in which
they can effectively operate. A grower
in a colder climate should shop for a
mini split air conditioner with a heat
pump that is rated for their particular
location. These systems can cool the
garden while the lights are on and
heat the garden when it is necessary,
such as when the lights are off.
The placement of a mini split system
or, more specifically, the placement
of the condenser unit (the part of
the system that is outdoors) is an
important part of winter preparedness.
Proper spacing and positioning will
influence how well the condenser