Recycling “Waste” Heat
An indoor grower who lives in a climate where it is necessary to heat
the “lights off” period of their flowering room stands to gain the most
benefits from a heat recycling setup. To successfully implement this, a
grower must have two flowering rooms operating on opposite 12-hour
light cycles. The heat is transferred from the room with its lights on
to the room with its lights off. To ensure the heat transfer is in sync
with the light cycle, the exhaust fan(s) should be programmed to
correspond with the light timer. In other words, when the lighting
equipment is on in flowering room #1, the heat that is being created
by the lighting equipment is ventilated into room #2, where the
lights are off. When the light cycle switches, the ventilation system
switches as well so that the room in its “lights on” cycle is always
providing heat to the room in its lights off cycle.
Without a heat recycling setup, an indoor horticulturist living
in a colder region would have to rely on a heating device to
maintain an ideal temperature within the flowering room during
the lights off cycle. However, when using the heat recycling
method, a heating device would only need to be used as a
back-up system. Most sophisticated indoor growing facilities
are equipped with automated heating and cooling systems.
During the winter months, these systems can alternate back
and forth from air conditioning (during the lights on period)
to heating (during the lights off period). Although growers
in colder regions get a respite from excess heat during the
winter months, they end up paying just as much to heat the
growing space during the lights off period as they would
to cool it during the other seasons of the year. Instead of
alternating from cooling to heating equipment in one
flowering room, a grower can opt for a dual flowering room
setup. This allows them to divert the excess heat from
flowering room #1 to maintain optimal temperatures in
flowering room #2. Over the course of the entire season,
a dual flower room setup with heat recycling can reduce
the cost of heating and/or cooling equipment and, in
turn, increase the grower’s overall return on investment.
“
THE IDEAL TYPE OF GARDEN
FOR HEAT RECYCLING is an
indoor garden with a closed air-
cooled reflector ventilation system.”
However, some indoor gardens are more suitable for heat
recycling than others. The ideal type of garden for heat
recycling is an indoor garden with a closed air-cooled
reflector ventilation system. A closed air-cooled system
takes fresh (cool) air from outside the garden space and
draws it through the lighting fixture(s), which, in turn, cools
the lighting fixture(s) and reduces the ambient temperature
of the growroom. As the air passes through the reflectors,
it becomes heated. Normally this heated air would be
exhausted outside. In a heat recycling system, the heat is
reused in the other flowering room during its lights off period.
Each closed ventilation system will need its own fan that
is ducted directly to the adjoining flowering room. When
employing a heat recycling system between flowering rooms,
light leaks are a major concern. A flowering room’s dark cycle
should always be kept as dark as possible and should never
be interrupted by light. To avoid light leaks, a black interior
ducting should be used, and the ducting should be bent into
a U-shape between the rooms. This will stop any light from
reflecting through the ducting.
Maximum Yield
31