FEATURESTORY
by Eric Hopper
Evaporative and Passive Cooling
in a Greenhouse
K
eeping a greenhouse cool throughout the
summer heat can be a difficult task. To
keep the plants within a greenhouse happy
and healthy, a horticulturist must maintain
a temperature in his or her greenhouse that is suitable
for plant growth. Extreme temperatures can cause
myriad of problems for greenhouse hobbyists, includ-
ing stunted growth, root pathogens, wilting and even
death.
Many greenhouse growers don’t realize there are
easy and inexpensive ways to help keep the tem-
perature within a greenhouse cooler. In some cases,
passive cooling techniques (cooling without energy
consumption) are enough to keep a greenhouse
within the desired temperature range. Sometimes the
combination of a passive cooling technique and an
evaporative cooling method is required to maintain
temperatures conducive to accelerated plant growth.
In the majority of situations, implementing passive
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cooling techniques will only help a grower reduce
the greenhouse’s heat signature, which automatically
reduces the energy costs of any additional cooling
equipment. Put another way, passive cooling tech-
niques help make cooling a greenhouse as efficient
and cost effective as possible.
Passive Cooling Techniques
As previously mentioned, passive cooling tech-
niques can be the key to most efficiently cooling a
greenhouse. Most passive cooling techniques are
pretty straightforward, but will generally require a
little forethought when setting up a greenhouse. It
is a good idea to figure out how the greenhouse will
be kept cool before beginning construction. Three
passive cooling techniques that can greatly affect the
overall temperature of a greenhouse are convection,
the use of a shade cloth, and strategically locating the
greenhouse.
www.GardenandGreenhouse.net
June 2018