Controlling the Greenhouse Environment

HeatingHot water heat system

heating water in a boiler and pumping the hot water through pipes located in the greenhouse located under benches, low maintenance, even heat

Steam heatboilers that bring water to a boil and the

resulting steam flows through pipes in the greenhouse

HeatingUnit heaters

heat air within the unit, then blow the air throughout the greenhouse. Polyethylene tubes evenly distribute air flow, cost more to operate

Infrared heat systemsproduce heat energy that is absorbed by the

plants, media, and benches, do not heat the air, suited for high greenhouses

CoolingFan and pad cooling system

Number 1 system, based on evaporation of water, pads at one end of the house are kept wet, fans at the other end of the house pull air through the pads. Air entering the house is cooled as water in the pads evaporates.

CoolingFog systems

involve an atomizer that produces water vapor, flash evaporation of this water cools the greenhouse.

Ventsconsist of panels that

open and allow air exchange with the outside, Natural cooling

Energy CurtainAutomated systems using fabrics that can

insulate a greenhouse at night and shade the crops during the dayInstalled gutter to gutter, run by computers

Short-day curtainsSimilar to energy curtains, provides darkness

that will simulate a short-day effect.

Climate Control SystemsEnvironmental controls

Devices used to turn greenhouse systems on and off, including heating and cooling systems.

Includes:ThermostatsAnalog controlsComputer controlsComputerized environmental management

systems

Climate Control SystemsThermostats are low cost, easy to install

environmental controls.On-off thermostats control fans, heaters, and

vents with the change of temperatures.Analog controls use proportioning

thermostats to run amplifiers and electronic circuitry.heating and cooling operations are integrated

resulting in better performance

Climate Control systemsComputer controls use microprocessors to

make complex judgments based on information from a number of sensors.

Computerized environmental management systems, although expensive, are accurate and can control all the automated systems together.

Automated Systems Incorporate technological developments in

the production of greenhouse crops.Automated systems cut down labor costs Automated systems allow for larger crops

Automated Systems- Planting Automated pot fillers

used to fill pots with medium, medium is lightly packed, and the pots are stacked or move down a conveyor for planting.

Automated seederspermit the sowing of entire flats or plug trays in a

few moments, trays move down a conveyor to a germination room or move to the greenhouse

Automated transplantersremove small plants from plug trays and

transplant them directly to pots.

Automated Systems- Transporting Transporting= most labor intensive part

Conveyor belt systems are used to move plants from one area of the greenhouse to another.

Tray mechanization, has grown in popularity in the U.S.Individual trays or palletized benches that hold 100

pots or more roll on a series of rails from one area to another.

Automated Systems: Watering Spaghetti tubing

Automated system that involves small tubes connected to a main line

End of each small tube is placed in a pot, and when functioning, dribbles water onto the medium.

Allows flowers and foliage to stay dry

Automated : Watering Drip irrigation

a system like spaghetti tubing

differs = provides a slow steady drip

Used with hanging baskets

Wastes less !!

Automated: Watering Ebb and flood

Watering involves watertight benches in which pots are set

Water or nutrient solutions are pumped into the bench, the medium absorbs the water, and the water drains away.

Little water loss, nutrient levels are easily adjusted, plant foliage kept dry

Automated: Watering Capillary mats

consist of porous mats placed on a bench and wetted.

The medium in the pots absorbs the water through capillary action.

Foliage stays dry, high humidity provided

Automated: Watering Irrigation booms

Move across the entire bench and well-placed nozzles flood the pots below as they pass over the plants

Commonly used with bedding plants, plug trays, and some potted flowering crops.

Automated: Watering Overhead sprinklers

Stationary sprinkler heads placed throughout the growing space

Large amount of water in a short period of time Often used with bedding plants.

Automated: WateringIntermittent mist

systemsProduce tiny droplets in

the air for the purpose of keeping plant material wet

Commonly used in the propagation phase of production to reduce water stress on cuttings

Continuous or programmed times

Vocabulary Review1. Analog controls2. Computer controls3. Computerized

environmental management systems

4. Energy curtains5. Environmental

controls6. Fan and pad

cooling system7. Fog system8. Hot water heat

system9. Infrared heat

system

10.Polyethylene tubes

11.Short-day curtains12.Steam heat13.Thermostats14.Unit heaters15.Vents16.Automated pot

fillers17.Automated

seeders18.Automated

transplanters19.Capillary mats20.Conveyor belt

system

21.Drip irrigation22.Ebb and flood23.Intermittent mist

system24.Irrigation booms25.Overhead

sprinklers26.Spaghetti tubing27.Tray

mechanization