Greenhouse Greenhouse StructuresStructuresWhat are the elements of a What are the elements of a greenhouse structure?greenhouse structure?

Key QuestionsKey Questions

What is a greenhouse structure?What is a greenhouse structure? What are the various design styles of What are the various design styles of

greenhouses?greenhouses? What are the structural parts of a greenhouse?What are the structural parts of a greenhouse? What are the differences between the What are the differences between the

transparent coverings used for greenhouses?transparent coverings used for greenhouses? What factors are involved in locating a What factors are involved in locating a

greenhouse?greenhouse? What are the different types of benches and What are the different types of benches and

bench arrangements used in greenhouses?bench arrangements used in greenhouses? What are the different methods used in What are the different methods used in

controlling greenhouse temperature?controlling greenhouse temperature?

What is a greenhouse What is a greenhouse structure?structure?

Greenhouse- Greenhouse- structure covered with a transparent structure covered with a transparent

material, which allows sufficient sunlight to material, which allows sufficient sunlight to enter for the purpose of growing and enter for the purpose of growing and maintaining plantsmaintaining plants

Greenhouse range- Greenhouse range- two or more greenhouses located togethertwo or more greenhouses located together

Headhouse- Headhouse- a central building attached to a greenhouse a central building attached to a greenhouse

and used for office, storage, and work spaceand used for office, storage, and work space

What are the various design What are the various design styles of greenhouses?styles of greenhouses?

Attached greenhouse- connected to a Attached greenhouse- connected to a buildingbuilding 1. Lean-to greenhouse1. Lean-to greenhouse 2. Attached even-space greenhouse2. Attached even-space greenhouse 3. Window-mounted greenhouse3. Window-mounted greenhouse

Freestanding greenhouse- separate from Freestanding greenhouse- separate from other buildings or greenhousesother buildings or greenhouses Need more land or spaceNeed more land or space More exposed surface area, therefore, More exposed surface area, therefore,

require more heatrequire more heat

Four types of Four types of Freestanding Freestanding GreenhousesGreenhouses

1.1. Even span- rafters of even lengthEven span- rafters of even length

2.2. Uneven span- rafters of unequal lengthUneven span- rafters of unequal length

3.3. Gothic arch- styled in the shape of a Gothic arch- styled in the shape of a pointed archpointed arch

4.4. Quonset- curved roofs with or without Quonset- curved roofs with or without side wallsside walls

Even Span/Gothic ArchEven Span/Gothic Arch

Uneven SpanUneven Span

QuonsetQuonset

Four types of connected Four types of connected greenhousesgreenhouses

1.1. Gutter-connected- several even-span Gutter-connected- several even-span greenhouses attached togethergreenhouses attached together

2.2. Venlo- different from gutter-connected in that Venlo- different from gutter-connected in that they are normally wider and have twice as they are normally wider and have twice as many ridges between supportsmany ridges between supports

3.3. Barrel vault- Quonset-style structure with Barrel vault- Quonset-style structure with attached sidesattached sides

4.4. Sawtooth- lean-to structures joined togetherSawtooth- lean-to structures joined together

Gutter-connectedGutter-connected

What are the structural What are the structural parts of a greenhouse?parts of a greenhouse?

1.1. foundation- support for the frameworkfoundation- support for the framework

2.2. Footings- concrete support for Footings- concrete support for foundation; located below the frost linefoundation; located below the frost line

3.3. Sidewalls or curtain walls- wall on which Sidewalls or curtain walls- wall on which the framework sitsthe framework sits

4.4. Ridge- top of the greenhouseRidge- top of the greenhouse

5.5. Anchor support posts- provide main Anchor support posts- provide main structural support for the greenhouse structural support for the greenhouse

6. Trusses- provide structural strength6. Trusses- provide structural strength

7. Purlins- run length of greenhouse 7. Purlins- run length of greenhouse connecting trussesconnecting trusses

8. Ventilators- moveable units that allow for 8. Ventilators- moveable units that allow for natural ventilation. They can be located natural ventilation. They can be located on the top or sides.on the top or sides.

What is the difference between What is the difference between the transparent coverings used the transparent coverings used for greenhouses?for greenhouses?

GlassGlass Usually expensive and hard to heatUsually expensive and hard to heat Double strength; grade B is usually usedDouble strength; grade B is usually used Sometimes, thermopane- a double of layer Sometimes, thermopane- a double of layer

of glass with ¼ to ½ inch dead air space of glass with ¼ to ½ inch dead air space between panes- is usedbetween panes- is used

Sash bars used with bar caps keep glass Sash bars used with bar caps keep glass in placein place

GlassGlass

Polyethylene- flexible plastic filmPolyethylene- flexible plastic film Initial cost of installation is cheaperInitial cost of installation is cheaper Fuel cost to heat is cheaperFuel cost to heat is cheaper Life span is short, usually three yearsLife span is short, usually three years Coverings are 4 mil or 6 mil thickCoverings are 4 mil or 6 mil thick Condensation can be a problemCondensation can be a problem

PolyPoly

Fiberglass- reinforced plasticFiberglass- reinforced plastic Corrugated polycarbonateCorrugated polycarbonate Less expensive than glassLess expensive than glass Easy to installEasy to install Longer life span than polyethyleneLonger life span than polyethylene Highly flammableHighly flammable Susceptible to ultraviolet, dust, and pollution Susceptible to ultraviolet, dust, and pollution

degradationdegradation

FiberglassFiberglass

Acrylic and polycarbonateAcrylic and polycarbonate Replaced the use of fiberglassReplaced the use of fiberglass Lightweight and easy to installLightweight and easy to install Excellent heat insulating and light Excellent heat insulating and light

transmissiontransmission Life of 15 yearsLife of 15 years FlammableFlammable Generally used on the ends or side wallsGenerally used on the ends or side walls

PolycarbonatePolycarbonate

What are the factors involved What are the factors involved in locating a greenhouse in locating a greenhouse range?range?

MarketMarket AccessibilityAccessibility Climate conditionsClimate conditions Topography and drainageTopography and drainage Water and other utilitiesWater and other utilities Zoning regulationsZoning regulations Labor supplyLabor supply ExpansionExpansion

Greenhouse rangeGreenhouse range

Should be oriented to present the least amount Should be oriented to present the least amount of shadows and achieve light intensityof shadows and achieve light intensity

Most important in N latitudes of N.A.Most important in N latitudes of N.A. Prevailing winds are also an important Prevailing winds are also an important

considerationconsideration Also consider entrances and drives that are Also consider entrances and drives that are

accessible for large trucks and sufficient accessible for large trucks and sufficient parkingparking

Location of headhouse and storage facility is Location of headhouse and storage facility is important to consider alsoimportant to consider also

What are the different types of What are the different types of benches and bench arrangements benches and bench arrangements used in greenhouses?used in greenhouses?

3 types of bench arrangements3 types of bench arrangements Longitudinal- runs entire length of the Longitudinal- runs entire length of the

greenhousegreenhouse Cross-benching- runs the width of the Cross-benching- runs the width of the

greenhousegreenhouse Peninsular- similar to cross-benching but Peninsular- similar to cross-benching but

has a middle aislehas a middle aisle

Types of benchesTypes of benches Wood bench fabrics- lath or snow fencingWood bench fabrics- lath or snow fencing Welded wire- 14-gauge galvanized wire Welded wire- 14-gauge galvanized wire

coated with a plasticcoated with a plastic Prefabricated plastic- lightweight, strong Prefabricated plastic- lightweight, strong

vinyl materialvinyl material Moveable benches- 14-gauge galvanized Moveable benches- 14-gauge galvanized

expanded wire on frames with steel rollersexpanded wire on frames with steel rollers

What are the different methods What are the different methods used in controlling used in controlling greenhouses temperature?greenhouses temperature?

Generally night temps should be 55-65 Generally night temps should be 55-65 degree F and day temps should be 65-80 degree F and day temps should be 65-80 degree Fdegree F

Ways to control tempWays to control temp HeatersHeaters Ventilation and evaporation cooling systemsVentilation and evaporation cooling systems Shading materialShading material

Types of heating systemsTypes of heating systems SteamSteam Hot waterHot water Forced air heatersForced air heaters Infrared radiant heatersInfrared radiant heaters

Types of cooling systemsTypes of cooling systems Natural ventilationNatural ventilation Fan ventilationFan ventilation Fan-tube or fan-jet ventilationFan-tube or fan-jet ventilation Fan-pad cooling systemFan-pad cooling system Fog-evaporationFog-evaporation

Shading MaterialsShading Materials LiquidLiquid Black polypropylene shade fabricBlack polypropylene shade fabric