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“Hanging” gardens of Babylon: ~600 B.C.
One of the seven wonders of the ancient world
2012 UA-CEAC GREENHOUSE CROP PRODUCTION &
ENGINEERING DESIGN SHORT COURSE
April 10, 2012
Location: 50 km S of Baghdad, Iraq
on the east bank of the Euphrates
River
Greenhouse Structures and Design
Built by: King Nebuchadnezzar II
(604-562 BC)
Dr. Murat Kacira
Associate Professor
Agricultural and Biosystems Engineering
Controlled Environment Agriculture Center
University of Arizona, Tucson, Arizona, USA
Early form of
“protected agriculture”
mkacira@cals.arizona.edu
Water lifted from the
Euphrates River by a
“chain pump”
(P. Rorabaugh)
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Egypt: several hundred years BC
1st Century A.D. Rome
Ancient Egyptian hieroglyphs:
people grew plants in water culture
14-37 A.D.
Ancient Egyptian agriculture
Cucumbers grown out of
season in structures
covered with
“transparent” rock (mica)
for the Roman Emperor
Tiberius.
Papyrus and lotus growing in the Nile River
First known use of CEA.
Other such structures
noted during that time.
(P. Rorabaugh)
(P. Rorabaugh)
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Why Greenhouses?
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What is Controlled Environment Agriculture (CEA) ?
Improved independence from outside climate
Grow year round
CEA, also known as Protected Agriculture, is
defined as an integrated science and engineeringbased approach to establish the most favorable
environmental conditions for plant productivity
while optimizing resources including water, energy,
space, capital and labor, and thereby to provide
the desired plant product or biological processes
under controlled conditions.
Usage of unproductive land
Efficient use of resources (i.e. water, fertilizer, labor,
energy)
More control over aggressors (pests & diseases)
Societal effects: steady, year round jobs
Considerable increase in production & quality
Superior Income!
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Challenges of the greenhouse grower
Grower against mother nature and the rest of the
world
Holland
10,370 ha
2,286 ha
57% Ontario
Poland
France
Canada
7,560 ha
9,620 ha
Spain
52,170 ha
Unites States
8,425 ha
Mexico
11,759 ha
Total Greenhouse Areas in
Major Greenhouse
Production Countries
in the World
Italy
26,500 ha
Greece
4,670 ha
Turkey
33,515 ha
Japan
49,049 ha
China
2,760,000 ha
S. Korea
57,444 ha
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Source:
Kacira, M. 2011. Greenhouse Production in US: Status, Challenges, and Opportunities. Presented at CIGR 2011
conference on Sustainable Bioproduction WEF 2011, September 19-23, 2011 • Tower Hall Funabori, Tokyo, Japan
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Source:
Kacira, M. 2011. Greenhouse Production in US: Status, Challenges, and Opportunities. Presented at CIGR 2011
conference on Sustainable Bioproduction WEF 2011, September 19-23, 2011 • Tower Hall Funabori, Tokyo, Japan
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Main factors for design and technology selection
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Market size and infrastructure in the region
Climate of the site
Plant requirements
Water quality and availability
Cost of land, availability and zoning restrictions
Availability of materials, equipment and services
Availability of dependable labor, level of
education/training of labor
Legislations: Food safety, chemical residue,
emission of chemicals to soil, water and air
Supporting infrastructure
Capital availability for investment, economics
Low tech
Medium tech
High tech
(Plant Factory, Terraspheresystems) (High tech, roof top GH, Gotham Greens)
Main factor effecting the technology selection
• Provide desired conditions for the canopy and
root zone using knowledge of the grower with
anticipated production quantity and quality.
• A reasonable balance needs to be established
based on market demand, grower skills,
expected economic return, and level of
greenhouse technology selected for crop
production.
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Greenhouse Designs
Greenhouse Designs
Roof vents
Winds
Wind
Even span
Taking advantage of the prevailing winds
for passive cooling.
Two slopes of equal pitch and width
Sawtooth
Roofs of unequal width and pitch
– Adaptable to slopes
Roof vents
For best ventilation with multi-span
Sawtooth designs, top-down vent
openings are recommended.
Uneven span
www.netafim.com
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Greenhouse Styles
Greenhouse Styles
Wide single span greenhouse
Quonset greenhouse
Arch greenhouse
“A” frame greenhouse
Retractable roof greenhouse 15
Open roof (Cabrio) greenhouse
Ridge and Furrow
(Gutter connected)
Venlo (Dutch) greenhouse
Multi bay (span) greenhouse
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Air inflated greenhouses
Single or Gutter Connected?
For energy conservation: For large
areas, gutter connected units have
less wall surface area relative to floor
area so are more energy efficient.
Advantages:
- No structural support elements
- Improved light transmission
- Low infrastructure cost
Disadvantages
- Power needs for positive pressure
- Wind/snow load concerns
GrandPa Dome Greenhouse, AGTC, Japan
Advantages with gutter connected:
• Allows future expansion
• Common access to bays
• Shared climate under one roof
• Sharing environmental control
system and other mechanical systems
• Less wall surface area relative to floor
area, thus less surface for heat loss,
and more energy savings
AirStream Innovations (http://airstreaminnovations.com/)
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Floating Lettuce Greenhouse
Outer diameter: 29 m
Cultivation Pool Area: 302 m2
Production capacity 195 heads/day
Low Tech GH with ETFE glazing
89.2 mph (40.2 m/s) designed wind load
6 blowers, 410 W/each
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Unusual greenhouse designs
Greenhouse Crop Production and Quality
Carefully select these greenhouse components!
Design is simply based on:
- Expectations,
- Needs
- Experience of the grower
US Botanical Garden Greenhouse
(Washington DC)
Biosphere 2 (Tucson, AZ)
Structure
Cover
Environmental control systems
Eden Project (UK )
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Picture: G. Giacomelli
Glass
Greenhouse Covering Materials
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• Light transmission, diffusion, light quality
• Mechanical resistance
• Heat loss, thermal resistance (R-Value)
Higher light transmission
Non-combustible
Resistant to UV radiation
Max. light: Use largest sheets of glass if possible
Vulnerable to hail
Tempered glass allows wider panes, safety.
Cost:  $9-10/ft2
• Condensation behavior
• Sensitivity to aging (temperature, UV, chemicals)
• Size
• Cost $$$
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(Picture(Photo
courtesy
credit :of
Dr.C.
C.Kubota)
Kubota)
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With Double Poly
Polyethylene-flexible plastic film
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Improve light transmission
Condensation between the layers reduces light
transmission into the greenhouse and may also lead to
algae build up.
Initial cost of installation is cheaper
Fuel cost to heat is cheaper
Life span is short, usually 3-4 years
Covering materials are 4 mil or 6 mil thick
Anti-fog materials to prevent condensation
IR blockers = less heat loss
Cost:  $ 0.16/ft2
Condensation must be prevented between the layers
- Use outside air to inflate the layer
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Polycarbonate
Acrylic
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Easy to install
Good light transmission
Good insulation properties
Flame retardant
Less flexible that Polycarbonate
and more prone to hail damage
• Longer life span than
polyethylene (20+)
• Cost: $3.5/ft2
• Easy to install
• Longer life span than
polyethylene (10+ years)
• Polycarbonate is much stronger
than glass, it is lighter in weight.
• Has good insulation properties
and is flame retardant.
• Widely used to glaze end walls
and gables in Quonset
greenhouses. And, on roofs of A
frame structures
• Cost:  $ 1.5/ft2
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Advances in Greenhouse Coverings
Comparison on characteristics
of glazing materials
Covering Material
PAR
Transmittance
(%)
Infrared
Transmittance
(%)
UV
Transmittance
(%)
Durability
(years)
30+
Glass
90
<3
70
Polyethylene (Double)
<80
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3-4
Polycarbonate
83
<3
18
8-10
Arcrylic (Twin wall)
86
<5
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20+
transmission
HEAT 
Increase greenhouse temp.
Photosynthesis & growth
TGH 
TPlant
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Advances in Greenhouse Coverings
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Greenhouse Orientation
Anti-reflection (AR) covering materials using nanomaterials on
sheet glass available (GroGlass, CentroSolar, Hanson ..)
• Increase transmission by 5-8%, 5% reduction in heat
radiation.
• Potential applications in Photovoltaics, Solar Thermal and
Greenhouses Cover.
ETFE (Ethylene tetrafluoroethylene)
• Increased transmission by 3%
• Self cleaning
• Light weight
Goal: Maximize light (and uniformity of light)
– Percent light entering a greenhouse depends on
“angle of incidence”
Angle of incidence
at low latitudes in winter
Normal of greenhouse
roof surface
Angle of
incidence
Smaller AOI, more light
entering the greenhouse
Angle of incidence
at high latitudes in winter
Normal of greenhouse
roof surface
Angle of
incidence
Light ray incident on
greenhouse roof
Hanson Industrial
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Greenhouse Orientation
Greenhouse Structural (Design) Loads
• Loads = Forces acting on the greenhouse structure
– Detailed info: National Greenhouse Manufacturer
Association (NGMA) standards
(http://www.ngma.com/standardpdf/DesignLoads.pdf)
Below 40° latitude:
• Ridges running N-S direction
• Provides better light distribution (moving shadows), more
important than light transmission optimization
• Dead Loads
Above 40° latitude:
• Ridges of single-span houses running East-West to maximize
light intensity in the greenhouse
• Run ridges of multi-span houses North-South for light
distribution
— Weight of all permanent construction including but not
limited to walls, roofs, glazing materials, service
equipments.
• Live Loads
– Loads due to temporary (< 30 days) structural elements
(hanging objects, temporary equipments) (Do not include
wind, snow or dead loads)
– Maximum allowable = 15 lb ft-2 or 73 kg m-2
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Greenhouse Structural (Design) Loads
Low Level of Technology
• Wind Loads
• No or minimal adjustments of the GH environment
• GH environment dependent on outside
• Passive ventilation (roof, side wall vents)
• No heaters
• Substrate (Soil)
• Low cost (< $25-$30/m2)
(< $2.50-3.00/ft2)
— In general, greenhouses should be designed to withstand
an 70-80 mile hour-1 or 31.3-36 m s-1 wind from the
direction which will produce the greatest loads.
—70-80 mph = 16-20 lbs ft-2
• Snow Loads
For flat roof greenhouses:
Pf = C C I P
tg
Pf :
Ctg :
Cc :
I:
Pg:
C s:
c
g
Flat roof design snow load [psf]
Thermal factor; 0.83 for heated GH, 1.0
for unheated or intermittently heated GH
Exposure factor; 0.6 for open-terrain; 0.9
for sheltered areas; 0.7 for all others
Importance factor; 1.0 for retail & public
access GH; 0.8 for all others
Ground snow load [psf]
Slope factor
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Sloped roof greenhouses:
Ps = Cs Pf
(Pardossi et al., 2004)
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LOW Technology Greenhouse
Natural ventilation for cooling
No supplemental
heating
Grown in soil
Quonset design
(Picture credit: G. Giacomelli)
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LOW TECH Greenhouse
“High Tunnels”
18.4 $/m2 ($1.7 per ft2) for structure
9.1 x 29 m (30 x 96 ft)
Screened/shade Greenhouse
26.6$/m2 ($2.5 per ft2) for structure
9.1 x 29 m (30 x 96 ft)
Complete Package (upper and baseboard lumber U-clamps,
end-wall lumber mount fittings and hardware, wiggle wire,
single- layer clear poly roof and ends, manual roll-up
ventilation systems)
(PolyText FieldPro Gothic)
Environmental Control
Daytime:
Cooling with side vent
Inside air temperature higher than outside
Nighttime:
No heating
Inside air temperature about equal to outside
Knowing day/night air temperatures for your location during the
season will help!
Medium Level of Technology
• Combined use of High and Low Technology
• Active and/passive cooling systems
• With/without heaters
• Simple environmental monitors and controls
• Substrate (soil/soilless)
• Cost ($30-$100 per m2)
($3.00-$10.00 per ft2)
Pardossi et al., 2004
(PolyTex FieldPro Gothic HT Greenhouse)
High Level of Technology
• Plant-response-based
environmental control to optimize
plant growth, maximize productivity
and fruit quality.
• Closed/recirculating fertigation and
hydroponic systems.
• Computerized climate control of
greenhouse (temperature,
irrigation, shading based on
integrated light, CO2 enrichment.)
• Cost is high ($100-$150 per m2)
($10.00-$15.00 per ft2)
Haygrove Super Solo High Tunnel
Greenhouse Technology Levels in the US
High Technology
EuroFresh Farms, Wilcox, Arizona
• 111 ha in Wilcox, 17 ha in Snowflake, 1 ha semiclosed greenhouse in Wilcox.
• Exceeding 75 kg/m2/year tomato production,
• Glass venlo type
• Tomatoes, cucumbers
Village Farms, Marfa, Texas
• 49 ha in Marfa, Texas, 0.6 ha semi-closed
greenhouse in Marfa, 12 ha in under construction.
• Exceeding 100 kg/m2/year tomato production.
• Plastic arch type
• Tomatoes
Howeling’s Greenhouses, Oxnard, California
• 50.2 ha in US, 21 ha in Canada, 16 ha
semi-closed greenhouse in Oxnard, CA
• Glass venlo type
• Tomatoes, cucumbers
Pardossi et al., 2004
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Greenhouse Technology Levels in the US
Greenhouse Technologies in the US
High Tunnels (HTs) Technology
High Technology
• Most total area of single free standing greenhouses
• In terms of numbers of HTs, the Northeast and Mid-Atlantic region holds 40%
of total HTs structures in the US. Around 1800 ha (based on 2007 survey
2007), is growing, and expected to grow in the next 10 years (Orzelek, 2009)
• Fresh, local food production, adaptability to urban settings
• USDA support $13M for more than 2400 farmers to install HTs
• Vegetables, Herbs, Small Fruit, Tree Fruit, Cut Flowers, Specialty Crops
• Interest in improving interior climate with low cost mechanization/automation,
alternative energy systems integration, and local resources utilization
Backyard Farms, Madison, Maine
• 16.9 ha in Maine
• Glass venlo type
• Tomatoes
Windset Farms, Las Vegas, Nevada and Santa
Maria Valley, CA
• 26 ha in-construction in Santa Maria Valley, CA
• Glass venlo type
• Tomatoes, peppers, cucumbers, eggplants
Permanent HTs
Temporary HTs
(Image credit: hightunnels.org)
Wholesum Family Farms, Amado, Arizona
• 4.8 ha in-construction
• Glass venlo type, semi-closed
• Tomatoes (organic)
(Images credit: Dr. M. D. Orzolek)
Urban Agriculture, Rooftop Farming Gaining Interest
Plant Factory (Indoor Plant Production)
Systems
- Minimal land use,
- Minimized water and energy use
- Fresh, pesticide-free produce regardless
of climate or location, year round.
Local food production
• Reduced transportation and fuel use
• Fresh food
• Support for local jobs and local farmers
• Pesticide free or organic food
Challenges
- High energy and facility installation costs
- Cultivation technology yet to be
established
- Lack of human/expert resources to
operate/manage the systems
- Limited types/varieties of crops available
(Photo Credits: J. Nelkin)
http://brightfarms.com/
Gotham
Greens,
NY
BrightFarms
http://www.terraspheresystems.com/
VertCrop, Valcent
http://gothamgreens.com/
From traditional to sustainable systems
Sustainability
Traditional Systems
Control the GH climate automatically
Environmentally
Sound
Economically
Viable
Socially
Supportive
Sustainable Production Systems
Reducing environmental
pollution by re-cycle and
reuse of resources
Establish production instruments
 Resource conserving
 Environmentally sound
 Economically viable
 Socially supportive
 Commercially competitive
Increasing yields
Decreasing the cost of
using resources
Providing stable
employment to people
Reduce pest/disease
infestation
Use of renewable
energy
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FACTS-DEMANDS-SUCCESS
FACTS-DEMANDS-SUCCESS
• There are many designs and structures to select from, thus
it is important to become familiar with the advantages and
disadvantages of each.
• Control aerial environment surrounding the
plant canopy
• Manage the root zone conditions
• Determine demand for the produce and
marketing periods
• Define seasonal environments to overcome
and manage
• Select technology level properly to meet your
needs/expectations!
• Control the plant environment, so you can control plant
growth, quality and nutritional content.
• Greenhouse environment continuously
affected by weather.
- Monitor the greenhouse environment
- Know conditions,
- React promptly and appropriately
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SOME USEFULL REFERENCES
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SOME USEFULL REFERENCES
Database for state incentives for Renewable and Efficiency
http://www.dsireusa.org/
National Greenhouse Manufacturers Association
http://www.ngma.com
Surviving the Energy Crisis, OFA
http://www.ofa.org/energy.aspx
American Society of Agricultural and Biological Engineers
http://www.asabe.org
Greenhouse Energy Cost Reduction Strategies, Michigan State Univ.
http://www.hrt.msu.edu/Energy/Notebook/Energy_Sec3.htm
University of Arizona, Controlled Environment Agriculture Center
http://ag.arizona.edu/ceac/
Horticultural Engineering, Rutgers University
http://aesop.rutgers.edu/~horteng/
High Tunnels
http://www.hightunnels.org
Michigan State University, Greenhouse Energy
Cost Reduction Strategies
http://hrt.msu.edu/Energy/Notebook/Materials_Sec6.htm
Center for Plasticulture
http://plasticulture.cas.psu.edu/default.html
Ohio State University Greenhouse Engineering Extension Program
http://www.oardc.ohio-state.edu
Energy Sources, Department of Energy
http://www.energy.gov/energysources/index.htm
Cornel University, CEA Program
http://www.cornellcea.com/
Energy conservation for commercial greenhouses, NRAES-3
Natural Resource, Agriculture, and Engineering Service (NRAES)
Greenhouse Management Online, Dept. of Horticulture, Univ. of Arkansas
http://www.uark.edu/~mrevans/4703/index.html
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