Greenhouse Design Considerations
Designing a greenhouse facility is a complex issue involving
many decisions, both horticultural and mechanical. Before we can provide advice
about the appropriate level of control instrumentation for your project, and
some general advice about your structural and equipment design alternatives, we
need to understood more about the nature of this venture. Here are a few
questions that will help us to develop a better picture of your proposal. We
realize you may not have all the answers for these, but if you have developed
any ideas or preferences they will be helpful. Please let us know the points
that you have not yet considered or do not have answers for as yet, since we may
be able to provide assistance with some of these issues.
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What is the intended crop and
cropping method? Will it be year-round or seasonal? Will you be using
hydroponic methods? Will you be using recirculation, or will it be a drain
to waste system?
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Where will these facilities be
located? What are the expected maximum and minimum outdoor temperatures?
What is the prevailing humidity? Is it a high wind area? Is it a high
lightning area? What are the anticipated climate setpoints and setpoint
tolerances for temperature and humidity?
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What types of structures are you
planning? What is the anticipated gutter height? Will you be using
horizontal thermal or shading systems, and/or vertical wall systems? Will
you be using supplementary lighting for all or some of the growing area?
What type of horizontal airflow mechanisms are you planning? Will the
facility be built in stages? If so, what is the projected minimum initial
size and maximum built-out size?
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What method of ventilation are
you planning? Do you prefer passive ventilation with fog/mist cooling or
active ventilation using pads & fans? If you are planning a pad and fan
system, what is the maximum length between the intakes and outlets?
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What heating system are you
planning? Do you plan to use conventional high mass hot water boiler and
tube-pipe system? Will there be a heat transport line or a central header?
Will you be using two-way, three-way, or four way valves? Will you be using
the heating pipes as transport rails?
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What method of irrigation are
you planning? What is the source of your irrigation water? What is the
quality of the irrigation water? What is the anticipated instantaneous
capacity (peak flow rate) and daily capacity of the irrigation system? How
many controlled irrigation zones will there be? What is the maximum On Time
and watering frequency for each zone? How many zones can be watered at once
(system capacity)? What type of irrigation distribution system are you
planning, a mainline system or a home-run system?
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What method of nutrient
management are you planning? Do you require nutrient control? Do you prefer
dilute tank or in-line fertilizer injection methods? Are you planning a
classic A/B concentrate fertilizer system with pH control, or something
different? How many individual nutrient recipes will you require
simultaneously? Do you prefer to use one large nutrient dosing system or
several smaller ones for redundancy?
-
Is the power supply single or three-phase? Do you have
natural gas available or will you be using an alternate heating fuel and/or
cogeneration?
Once we understand your performance specifications, we can
begin to work on specific structural, equipment, and control strategy issues.
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