Greenhouse Range- Two or more greenhouses side

by side Attached Greenhouse- Connected to building, floral

shop, garden center, office, home, ect. Attached Even-span, window mounted, lean-to

Freestanding- Separate from other buildings Even-span, uneven –span, Quonset, Gothic arch

Connected Greenhouse- Does not include sidewalls within structures Gutter-connected, dutch, barrel vault, sawtooth

Identify the different types of greenhouses and their

arrangements

Attached:

Less construction material Can be used to head and cool homes

Attached Even-span More available space

Free standing: Maximum sunlight available for plants Allow regulation of many different types of plant

environments

Match the greenhouse structures with their

advantages.

Freestanding

Even-span Allows more freedom of space/ Movement and

equipment

Connected: Less construction material Less land needed Heat conservation due to less exposure Workers and equipment can move through buildings

Match the greenhouse structures with their advantages

Cont.

Describe the internal structures and equipment of a greenhouse

Frame Pressure –treated wood Aluminum Galvanized steel Note: Glass green houses require more structural

support that polyethylene Foundation

Continuous concrete bed upon which greenhouse is built

Water and electrical lines are place

Describe the internal structures and equipment of a greenhouse

cont.

Concrete Footings Non-continuous supports located below the frost line

(cannot be affected by frost heaves). Take the place of foundation Spaced at intervals according to placement of support

anchor posts Sidewalls

Between the footings and supports Holding greenhouse covering in place

Describe the internal structures and equipment of a greenhouse

cont.

Common components of greenhouses: Ridge – Top of greenhouse; runs the length of the

house Anchor support posts – Provides structural support Trusses – Adds structural support

Consists of rafters, chords, and struts Purlins – run the length of the greenhouse, bolted to

each truss and adds structural support Ventilators – attached to the sides or ridge of the

greenhouse these open to allow ventilation

Describe the internal structures and equipment of a greenhouse

cont.

Greenhouse covering Glass

Provides excellent light transmission Long lasting Double strength, grade B weight used for greenhouse

except in cold areas Expensive installation and heating Requires good structural support of aluminum or steel

Describe the internal structures and equipment of a greenhouse

cont.

Greenhouse covering Polyethylene

Inexpensive installation Low heating cost Short-lived UV inhibitors increase its life span Produces condensation which increases wet plant foliage

and disease possibilities Light reduction compared to glass

Describe the internal structures and equipment of a greenhouse

cont.

Greenhouse covering Corrugated Fiberglass – Reinforced Plastic

Low in cost Ease of installation Tensile strength Longer lifespan Good light penetration Can degrade over time from ultraviolet damage, dust &

pollutants Flammable and may increase insurance costs

Describe the internal structures and equipment of a greenhouse

cont.

Greenhouse covering Acrylic

Light weight Ease of installation Good lighting transmission Long lifespan Flammable

Describe the internal structures and equipment of a greenhouse

cont.

Greenhouse covering Polycarbonate

Lightweight Ease of installation Good heat insulation Good light transmission Available in clear, corrugated single layer panels Good replacement of corrugated fiberglass Flammable

Describe the internal structures and equipment of a greenhouse

cont.

Interior & exterior design Drives should be wide for trucks Shipping and receiving doors should be

accommodating to and from the drive Parking for customers and employees Location of offices should be easy to access from

shipping area

Describe the internal structures and equipment of a greenhouse

cont.

Benches and Beds In-ground beds- used for fresh florals Raised benches- used for potted plants Floor- used for potted plants. Surface is gravel for

percolation and weed control Three styles of concrete in-ground benches:

Longitudinal- runs length of greenhouse, used for in-ground beds

Cross-benches- runs the width, aisles run along sidewalls & between benches

Peninsular- Benches extend to sidewalls, aisles run down the center and between benches

Describe the internal structures and equipment of a greenhouse

cont. Benches and Beds

Four types of raised benches Wood bench fabric

Bench top consisting of wood connected by wire, rolled out over a bench frame, good for growing in large pots or flats

Welded 14 gauge wire coated with plastic, with mesh of 1-2 inches,

good for a variety of plants Prefabricated plastic

Vinyl by the square foot, can be customized to fit the bench, good for growing large pots or flats

Movable (floating aisle) 14 gauge galvanized wire on frames, mounted of steel rollers,

rollers allow the bench to be movable to the right or left, this creates a need for only one aisle in the greenhouse.

Describe the internal structures and equipment of a greenhouse

cont.

Shading Fabric

Black polypropylene pulled over the greenhouse to reduce light intensity and temperature, comes in a range of shades

Compound Liquid compounds applied to glass or polyethylene covered

greenhouse to reduce light intensity.

Describe the internal structures and equipment of a greenhouse

cont.

Aisles and walks 3-4 feet wide Concrete or gravel, depending upon the amount of use

Night Temp: 55-650 F (min 40 - max 850 F) Max. Day Temp: 10-15 degrees higher Consider:

Fuel Available Size of Greenhouse Operational Cost Covering & # of Layers Site of Greenhouse: Wind Requires Min. Maintenance / Auto Operation

Heating

Locate Thermostat at plant height w/ shade over top to avoid false readings

Vented Heaters: Down drafts caused by chimney not high enough to clear ridge of g.h. (at least 2’) open doors & vents can cause draft

HEATING SAFETY MARGIN: Rule of thumb: for est. heat loss 1.2 BTU per hour

for each degree of temp differential per sqft of exposed surface

Describe the internal structures and equipment of a greenhouse

cont.

Heating Unit heaters- Can be fired by natural gas, propane, fuel

oil, coal or wood. Electricity is not recommended.

Attached Structures: Extension of Home Heating System

Hot Water: Extend Pipes into Greenhouse Hot Air: Add Ducts and Thermostats Open Door and Fan Blow in House Heat

Free Standing Structures: Space Heaters w/ Electric Fans

Low Cost for Small Greenhouse Force Hot Air Heaters

Heater w/ air circulation system & chimney PLASTIC PUNCHED TUBE HORTIZONTAL AIR FLOW FANS

Types of Heating

Hot Water or Steam Heat Piped in Greenhouse More popular heating w/hot water in localized

benches Electric Heaters

Overhead heating + Soil heating cables provides a localized plant environment which allows

plants to thrive when surrounding air is lower than normal

Solar Heating Use of black painted drums filled w/water to absorb

heat & release it back into the environment

Describe the internal structures and equipment of a greenhouse

cont. Cooling

Fan and Pad Exhaust fan draws air through moist cellulose pad, air is

cooled through evaporation, for dry air conditions Fog Evaporative

Fog is generated within the greenhouse, heat is absorbed by the water droplets and evaporated, cooling the greenhouse environment, use in propagation houses.

Ventilation & Circulation System Roll up screens of wood

Lath available w/pulleys: decrease radiation 50%

Shade Cloth uniform shade, exact degree of shade, light wt.

& easy to install Paint - On Shades: glass & polycarbornate

mix w/ water and spray on remove w/ hot water & soap & brush

Cooling the Greenhouse

Vinyl-Plastic Shading:

Rolls 55-65% shade apply by washing area & smoothing plastic on area

Fan & Pad: Evaporative Cooling Moves air through a wet pad and it takes 1000 BTUs of

heat to change 1lb of water to vapor = reduction of air temperature

Cooling capacity depends on the outside humidity Equipment Needed:

PADS PUMP PVC PIPE WATER TANK (1 GAL/ FT LENGTH OF PAD) VENT

MIST COOLING

SPRAY TINY WATER DROPLETS INTO AIR REQUIRES MANY MIST HEADS OPERATED AT

HIGH PRESSURE

PROBLEMS: IF MIST CARRIES ANY MINERALS DEPOSITS CAN

BE LEFT & DAMAGE FOLIAGE, WET FOLIAGE INCREASE DISEASE PROBLEMS

Describe the internal structures and equipment of a greenhouse

cont. Ventilation

Natural Air exchange is fostered through open ridge and side

venting, under thermostat control. Not advised for winter cooling.

Fan tube Fans bring in cool air which is mixed with the warm air and

distributed through holes in plastic tubing that runs the length of the greenhouse.

VERY IMPORTANT FOR AIR MOVEMENT

PLANTS GROW BETTER WHEN AIR IS CONTINUOUSLY CIRCULATING

COOLS & WARMS LEAF SURFACE PROVIDING UNIFORM TEMP.

REMOVES WARM MOIST AIR & REPLACES W/ DRIER AIR (DECREASE DISEASE)

DECREASE THE INSIDE TEMP DURING SUNNY DAYS

SUPPLIES CARBON DIOXIDE TO PLANTS

Ventilation

Need:

Ridge Vents: remove hot air at highest pt of greenhouse

Side Vents: side of the house to provide desirable air currents

Hand Operated Roof Vents Automatic Ventilation System

Control by thermostat Exhaust Fans: need to be large enough to have

complete air exchange in 60 seconds

Types of Ventilation

Ridge Vents

Ridge Vent Exhaust Fan (1, 2 speed for small houses) Vents in back of Greenhouse Air Circulation: Poly Tube or Air Flow Fans Horizontal Air Flow Fans:

Fans should operate continuously to push air horizontally on one side of house & in opposite direction on other side of house

Position Fans at least 12” from the Roof

Ventilation Equipment

Horizontal Air Flow Fans