Dehumidification of Greenhouses in Cold Region

ABE 990
When: 1:30 PM, Friday, February 26, 2010
Where: 1A80 Engineering
Speaker: Gao Zhu (M.Sc. student)
Dehumidification of Greenhouses
in Cold Region
One major challenge greenhouse producers face is the excessively
high relative humidity (RH) during cold seasons which result in fungi
diseases and reduction in yield and quality. Conventional
dehumidification by increasing ventilation rate is either costly because
of the resultant heat loss or ineffective in spring or fall when outside
RH is high. In this study, two dehumidification technologies, i.e. air to
air heat exchangers and mechanical dehumidifiers, were evaluated in
a Saskatchewan tomato greenhouse, and laboratory tests using
chilled water condensation system, another potential dehumidification
method, were conducted to investigate its dehumidification effect
under different environment conditions.
The three dehumidification methods were evaluated against the
conventional one based on moisture removal efficiency (MRE) and
the energy cost. This presentation mainly focuses on the MRE
comparison of the three methods. It was concluded that dehumidifiers
were the most energy efficient in heating season; heat exchanger and
dehumidifiers were both functional for heating season but not
desirable for cooling season due to the added heat to the
greenhouse; the chilled water condensation method consumed much
more energy when removed certain amount of water compared to the
others, thus the least competitive.