Structural Parts Greenhouse Types Even Span: Self-supporting commercial greenhouse and is the most...
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Transcript of Structural Parts Greenhouse Types Even Span: Self-supporting commercial greenhouse and is the most...
Greenhouse Types
Even Span: Self-supporting commercial greenhouse and is the most common type of greenhouse
Ridge-and-furrow: Two or more even-span greenhouses connected together at the eaves
Contiguous: Two or more even-span greenhouses with inner walls separating each greenhouse
Greenhouse Types
Quonset: Upside down half circle made of laminated wood or bent pipe. Can also have raised walls
Gothic: Slightly pointed greenhouse covered with corrugated fiberglass. Provides greater load bearing for accumulation of snow
Lean-to: Seldom used commercially and found attached to the south wall of a south supporting structure
• When building a greenhouse frame consider:– The strength and weight of the materials– The amount of shade cast by the frame
• The frame is composed of:– Perlins– Sash bars– Side posts
Greenhouse Frame
• Aluminum– Alloy: Aluminum combined with other
materials to increase strength and flexibility with rust and rot resistance
• Plastic pipe• Wood or wood
combination
Framing Materials
Covering Materials
Cover Type Advantage Disadvantage
Glass• Best for transmitting
light to plants• Initially expensive• Easily broken
Plastic, flexible
• Provides insulation• Inexpensive
• Pass less light to plants• Considered temporary• Often need replacement
after one or two years
Plastic, rigid
• Last longer that flexible plastic
• Less chance of breaking• Withstand weather
better than flexible plastic
• Will eventually yellow or weaken
• Pass less light than glass
• Unit heaters• Hot water heat• Root zone
heaters• Steam heat• Infra-red heating• Solar heating
Heating Systems
• Evaporative cooling– Pad absorbs water and
exhaust fans pull air through the pad and greenhouse
• Natural cooling– Replaces air inside
greenhouse with outside air
• Fog cooling– Fog nozzles installed in
greenhouse emit a fog
Cooling Systems
• Raised benches: raised off the floor, generally 24-36 inches
• Ground beds: constructed directly on the floor and filled with media
• Movable benches: also called rolling benches, raised bench built to roll sideways
• Ebb and flow bench: raised bench approximately 3-6 inches deep and capable of holding water
Benches and Beds