Odum’s Energy Ecology & Green Houses Local and Ecological
Odum’s Energy Ecology & Green Houses
Local and Ecological
Outline Odum Energy, Ecology
and Economics Food Supply Greenhouses Growth Systems Ecology of
Greenhouses Energy in Greenhouses
Heat Gain and Loss Energy Value Efficiency
Passive Solar Design Orientation
Recap: Importance of Growing Local
Living Building Examples
Odum’s Energy Ecology Growth Priming:
Favors economic vitality Quality Vs. Quantity
Reduction of subsidies Quality of Life
From steady state periods Net Output Richer than
Input Solar Conversion
Necessary Simpler Agriculture as a
Primary Solution
Applied to Food Supply Food = Basis for Society Quality of Energy:
Stability and Growth Vitality of Food Growth Materials
Quality of Life: More Time with People Application of Purpose
Food Supply Considerations Human Population
Estimated 9 billion in 2050 (6.6 billion in 2008) 2/3 Expected to be Urban Dwellers
Global Warming Influence
Food supply Agriculture systems Arable land
Influences Water Supply Needs to increase clean supply Needs to increase availability and distribution
A Look at Green Houses Human and Natural Ecology Combined Local Energy Capture and Storage
Input Energy Stored for Output Energy Use Local Energy Generation and Savings
Uses Natural Processes and Natural Storage/Blocking Carbon and GHG Neutrality: Possible! Community Based Designed
Based on need, and available resources Enhance Food Security Adaptable Efficient
Automation possible
Types of Growth Systems Mono Culture Polyculture Biodynamic Hydroponics Aquaculture Algae for Energy
Growth
Ecology of Green Houses Incorporate with Waste Streams or Algae
Culture for Nutrient Enhancement Create ‘Green Space’ in Office Space
Reduce Building Energy Needs Reduce Footprint of Greenhouses and Food
Supply
Reduce Nutrient Runoff Through Monitoring
Energy in Greenhouses Energy from our environments
Continuous and Renewed Solar, Organic, Natural Gas*, Water, Wind, Wood
Stored Coal and Fossil Fuels, Natural Gas*, Nuclear
In Ecology: Where continuous energy creates/generates stored energy Smart energy use is the lower energy ‘cost’ to produce the
same stored energy and/or energy output
70-80% Used for Heating; 10-15% for Electricity [2]
Heat Gain & Loss Conduction
Heat conducted through materials U-value – Btu/(hr-ºF-sq.ft.)
Convection Heat exchange between moving
fluid (air) and solid surfaces Radiation
Heat transfer between two bodies without direct contact or transport medium
Sunlight Air Leakage/Infiltration
Exchange of interior and exterior air
through small leaks and holes.
Increasing Energy Value Growth Versus and Towards Stability Reduce inefficiency of energy growth process
Reduce Dependence on Fuel subsidies Reduce Use of Non-Renewals Reduce Pollution Increase Output Recycling
Increase Efficiency of Current Systems Reduce outputs for maintenance and general operation.
Enhancing Efficiency Stand alone
Isolated growing conditions Include lots of plants to heat Natural ventilation
Opening Side Walls or Top Windows
1.7-1.8 – heat loss area to floor area (3000sq. ft.)
Materials selection Water Collection/ Indoor Storage Color Selection Orientation
Passive Solar Design[3]
Passive Solar Design (con’t)
Greenhouse: Passive Solar Design Thermal Mass
(BTU/sqft/Fo)
Brick 24
Concrete 35
Earth 20
Sand 22
Steel 59
Stone 35
Water 63
Wood 10.6Attached greenhouse:
2.5 gallons per sq. ft. of south facing glazing area for cool climates (4 month winters)2 gallons per sq. ft. of south facing glazing area for temperate climates (3 month winters)
1 gallon per sq. ft. of south facing glazing area for warmer climates (2 month winters)
Free standing greenhouse: 3 gallons per sq. ft. of south facing glazing area for cool climates (4 month winters)
2.5 gallons per sq. ft. of south facing glazing for temperate climates (3 month winters)2 gallon per sq. ft. of south facing glazing for warmer climates (2 month winters)
Sample R and U Values
Polycarbonate 6mm quad wall R = 1.79
Polycarbonate 8mm quad wall R = 2.13
Polycarbonate 16mm triple wall R = 2.5
Polycarbonate 8mm triple wall R = 2.0-2.1
Polycarbonate 8mm double wall R = 1.6
Acrylic double wall R = 1.82
Glass double layer R = 1.5 – 2.0
Glass double layer low-e R = 2.5
Glass triple layer 1 / 4 “ ( 0.6 cm) air space R = 2.13
Fiberglass glazing- single layer R = .83
Polyethylene Double 5mil film R = 1.5
Polyethylene Double 6mil film R = 1.7
Polyethylene single film R = 0.87
6 inches (15 cm) of fiberglass bat insulation R = 19.0
Polystyrene (styrofoam) 1 inch (2.5 cm) thick R = 4.0
Orientation East/West to Maximize Winter Sunlight Incorporate Cooling Sections for Air Flow Moveable Gutter Overhangs
[3][6]
Increase Energy Value of Food Grown in biodynamic, or polyculture systems Grow and Buy Organic Process By Hand Picked When Ripe Food Eat Fresh Soil Enhancement
External Greenhouse Example: Vertical Wall Green House Increased Food Supply Hydroponics Double-Skin Facades Reduce Maintenance
Provide Shade Air Treatment Evaporative
Cooling Reduced Costs
Mitigation Insulation
BioMachine: Buildings of Future Incorporate Automated Systems
Clean Air Enhance Nutrients Irrigation Supply and Water Management Local Harvesting
Solar Panels Solar Thermal Passive Heating and Cooling
Conclusions Human Ecological Incorporation Total Waste and Energy Stream
Considerations Reduced Need for Energy Increase Food Supply and Security Adaptability and Self Design
References[1] - HT Odum- Energy Ecology and Economics
[2] Sanford, Scott; Energy Conservation for Greenhouses; http://www.uwex.edu/energy/pubs/GreenhouseEC_SAREApril2010.pdf
[3] Sethi, V.P.; Survey and evaluation of heating technologies for worldwide agriculture greenhouse applications; 2010
[4] Sethi, V.P. ; Experimental and economic study of a greenhouse thermal control system using aquifer water; 2007
[5] Theodore Caplow; Vertically Integrated Greenhouse: Realizing the Ecological Benefits of Urban Food Production; Ecocity World Summit 2008 Proceedings; 2008
[6] David Roper; Solar Greenhouses; http://www.roperld.com/science/solargreenhouses.htm