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Greenhouses

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Oakcrest High School, Mays Landing ... without the columns the heat closures can be used to conserve ... carry weight of glazing material, snow, and wind. ... – PowerPoint PPT presentation

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Title: Greenhouses


1
Greenhouses
  • Designed and Researched by
  • 1999-00 Greenhouse and Turf Management Class
  • John Koster, Paul Marsh, Jamie Wade, Nick Maneri
  • Dan Dorfee, Jared Neid, Rob Stanley

Oakcrest High School, Mays Landing NJ
2
Greenhouse
  • Greenhouse location is very important, when
    placing your green house you must remember you
    will have to deliver your plant crops at all
    times of the year.
  • Keep your greenhouse next to major roads to be
    sure that they are open through all times of the
    year to get goods to youre retailers

3
What is a greenhouse?
  • A greenhouse is an area designed to grow plants.
  • It is a controlled environment which allow
    optimum growth.
  • When several of these buildings are joined
    together they are often referred to as a
    greenhouse range.
  • A greenhouse at home is usually attached to the
    house or the garage.

4
Location
  • There are several factors to be considered in
    establishing a greenhouse range.
  • A. Room for expansion
  • 1. Land larger then immediate needs should be
    acquired.
  • 2.Area should be added to this figure to
    accommodate service buildings, storage, and
    access drivers.

5
  • B. Topography
  • 1. The building site should be as level as
    possible to reduce the cost of grading.
  • 2. The site should be also well drained. Due to
    the vast amount of water in the green house it is
    always advisable to provide a drainage system.
    Try to select a site with deep, well drained
    loam, or sandy loam soil.

6
  • 3. You should select a site with a natural wind
    break such as a tree line or a hill.
  • C. Land use Prediction
  • 1. Local zoning and tax laws are subject to
    change brought on by development pressures. Such
    changes have brought about the termination of
    many greenhouse business.

7
  • D. Climate
  • 1. The greenhouse site should be selected with
    specific crops in mind.
  • E. Accessibility
  • 1. A site should be selected which has easily
    accessible shipping routes.
  • 2. Select a site that isnt long distance.
  • 3. Site location is often the deciding factor in
    the type of fuel used.

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9
Types of Greenhouses
  • Even Span
  • Uneven Span
  • Lean-to
  • Quonset
  • Gothic Arch
  • Curvilinear
  • Dome Shaped

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12
Detached Greenhouses
  • Detached Greenhouses - freestanding greenhouses
    that maybe constructed in one of several
    different styles.

13
Even Span Greenhouses
  • A detached greenhouse style that is most commonly
    used today for single houses or for several
    houses connected together to form one huge
    structure.
  • Usually have clear spans with truss supports
    rather then supporting columns without the
    columns the heat closures can be used to conserve
    energy

14
Uneven Span Greenhouses
  • One side of the roof is longer than the other
    side
  • When the longer side would face south, the suns
    heat could be used to maximum advantage
  • High fuel costs are causing growers to switch
    back to this type of greenhouse

15
Lean-to Greenhouses
  • Built against other greenhouses or building
  • The roof slopes to one direction usually facing
    south
  • Small and may be added to other structures
  • Used mostly for bulb-forcing or seed starting
    operations Lean-to-greenhouse is a half a
    greenhouse,split along the peak of the roof or
    ridge.
  • This type of greenhouse is nice to have when
    space is a problem.

16
Quon-set Greenhouses
  • Used during World War II for storage sheds
  • inexpensive and easy to buildFreestanding style
    is often a Quonset.
  • Quonset is a arch shaped house, a bad thing about
    theses is the lack of height near the side walls.

17
Gothic-arch Greenhouses
  • Not widely used
  • Framework formed from laminated wooden trusses
  • The trusses are made up of a bunch of wood glued
    together
  • Potted plants are usually grown in this type of
    greenhouse

18
Curvilinear Greenhouses
  • Used in city parks, botanical gardens, and
    wealthy individuals as conservatories
  • Was used for large conservation.

19
Dome shaped greenhouse
  • Rarely used in the common flower greenhouse,
    because it is such a small greenhouse. But it is
    usually found in at technical institutes.

20
Structure materials
  • Galvanized steel rods make up the frame .
  • The frame is covered with sheets of polyurethane
    with air space in between the two sheets to act
    as an insulation .
  • Also glass and polyester can be used.

21
Greenhouse Materials
  • Frame work components
  • Slash-sill provides a base for the glass.
  • Eave plate sits on side post supports roof
    members.
  • Gutter-collect runoff water and take it away from
    the building.
  • Drip gutter-condensation that forms on the inside
    of the glazing go to the ground.

22
  • Slash-bars must carry weight of glazing material,
    snow, and wind.
  • The bar-caps hold glazing in place located on the
    exterior of the greenhouse.
  • Purloins run the length of the greenhouse to
    support the slash bars
  • Framing materials must be strong, light, and be
    able to cast a shadow.

23
Climate control
  • The heating requirement of a greenhouse depends
    on the types of plants in the greenhouse.
  • The greenhouse heating must be adequate to
    maintain the desired temperature day or night.
  • Site location is often the deciding factor in the
    type of fuel used. In some regions natural gas
    has been a cheaper source of energy then other
    fuels.

24
Climate Control
  • 1. Heating
  • The requirement for heating a greenhouse resides
    in the task of adding heat at the rate of which
    it is lost.
  • Heat is lost by conduction.
  • Unit heaters are often referred to as forced air
    heaters.

25

Fuels
  • There are many types of heating oil, gas, wood,
    or electric.The heat can be distributed by forced
    hot air, radiant heat,hot water or steam.
  • To keep greenhouses warm in the winter install
    fans to keep the heat circulating .

26
Controls
27
Heating Systems
28
Air circulation
  • Without the fans the hot air rises and the cold
    air settles around the plants.
  • A small fan that blows 3 feet air in a min. is
    equal to one quarter of the air volume.
  • In a small greenhouse you should place the fans
    diagonally opposite corners the goal is to
    develop a circular pattern of air movement .

29
Heating and Cooling Ducts
30
Ventilation
  • Ventilation is the change from old air to new
    air.
  • Natural ventilation is when you have vent in the
    ridge line of the roof.
  • Mechanical ventilation - an exhaust fan to move
    the air out one end of the greenhouse while it is
    sucked in the other end.

31
Continue
  • Ventilation needs may vary because with weather
    and seasons.
  • First you must decide how much the greenhouse
    will be used.
  • In summer one half the air amount needs to be
    changed.
  • In the winter 20 to 30 of air volume changes.

32
Continue
  • By using LS screens you can deflect solar
    radiation as needed.
  • With a shade retention system you can open the
    side walls and or roof of the structure .

33
LS Screens
34
Water systems
  • Water is an essential need.
  • Hand watering is one way
  • Automatic system can be designed to water as
    needed.
  • Time clocks and mechanical evaporation can be
    used to control watering systems.
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