Greenhouse Production 1-4 test

Romans

Invented the first known greenhouses

Roman greenhouses materials

Stone walls covered with mica

Roman greenhouse heating

Fires burned outside walls to provide warmth

Glass tax repeal

Repeal of the glass tax in 1851 made greenhouses affordable in England

Light consideration

Proper sun exposure increases plant growth and greenhouse success

Natural shading

Trees provide shade in summer to prevent overheating

Orientation

Direction a greenhouse faces affects light and heat efficiency

Foundation

Level and well drained ground supports greenhouse stability

Accessibility

Easy access to water power and pathways improves greenhouse use

Italians

Built the first modern glass greenhouses

Greenhouse

Structure covered with transparent material for growing plants

Range

Two or more greenhouses placed together or connected

Bay

Section of plants with a walkway

House

Short term for greenhouse

Glazing

Material that covers a greenhouse

Attached greenhouse

Connected to another building and usually non commercial

Freestanding greenhouse

Separate structure with its own walls and roof

Connected greenhouse

Multiple greenhouses joined at the gutters

Greenhouse framing materials

Galvanized steel aluminum wood and PVC

Most common large greenhouse framing

Galvanized steel

Best light transmitting glazing

Glass

Least expensive glazing

Polyethylene

Poly lifespan

Usually lasts up to three years

Poly

Short name for polyethylene

Cold frame vs hot bed

Hot beds use extra heat while cold frames rely on sunlight

End wall

Short wall at front or back that supports structure

Side wall

Long wall along sides often used for ventilation

Louvers

Slatted openings that increase airflow

Vents

Roof openings that release heat and moisture

Evaporative cooling system

Fans pull hot air through wet pads to cool the greenhouse

Greenhouse heating systems

Hot water steam forced hot air and infrared

Hot water heating

Heated water circulates through pipes to warm plants

Steam heating

Pressurized steam releases heat through pipes

Forced hot air heating

Heaters blow warm air through the greenhouse

Infrared heating

Radiant heat warms objects instead of air

Exhaust fans

Remove hot humid air from greenhouse

Circulation fans

Mix air evenly inside the greenhouse

Greenhouse flooring types

Concrete porous concrete landscape cloth and gravel

Hand watering

Plants watered manually with hose or can

Overhead sprinklers

Sprinklers above plants that mimic rainfall

Drip irrigation

Water delivered directly to plant roots

Boom irrigation

Moving system that sprays plants evenly

Automated watering

Controlled by timers or sensors

Water trays and saucers

Hold excess water and keep soil moisture steady

Subirrigation types

Capillary mat trough ebb and flow and flood floors

Capillary mat system

Plants absorb water from a wet mat

Trough system

Nutrient solution flows through sloped channels

Ebb and flow system

Benches flood and drain to water plants

Flood floors

Floors flood evenly then drain for irrigation

Thermometer

Tool that shows current temperature

Thermostat

Device that controls heating or cooling systems

Supplemental lighting types

LED HID halide fluorescent induction and incandescent

LED lighting

Energy efficient lights with adjustable plant wavelengths

HID lighting

Very bright lights used for plant growth

Metal halide lighting

Blue light that supports vegetative growth

Fluorescent lighting

Cool lights used for seedlings

Induction lighting

Long lasting efficient full spectrum lights

Incandescent lighting

Inefficient lights that produce excess heat

Photocell benefit

Automatically controls lights to save energy

Photocell

Sensor that responds to light levels

Shade cloth uses

Reduces heat and prevents plant damage

Type II glazing

Fiberglass reinforced polycarbonate or acrylic

Type II glazing cons

Loses light over time and is highly flammable

BTU

Unit that measures heat energy

BTU formula

Thermal resistance times temperature difference

Subirrigation

Watering plants from the root zone

Type III glazing

Glass

Greenhouse fan types

Exhaust fans and circulation fans

Negative pressure system

Exhaust fans pull air in through cooling pads

Positive pressure system

Fans push cool air into the greenhouse so warm air rises and exits through ridge vents

Igloo

Lean-to

Shade house

Gothic

Ridge and furrow

A-frame

Uneven

Skillion

Sawtooth

Tri-penta

Dome

Tunnel

Flat arch

Gable

Uneven span

Even span

Quonset

What is the big difference between cold frames and hot beds?

a hotbed has a supplemental heat source (like manure, electric cables, or hot water) in addition to the sun, while a cold frame relies only on solar energy

The difference between the end wall and side wall in a greenhouse.

End walls are the shorter, typically vertical, gable

ended walls at the front and back, often containing doors and acting as primary structural supports against wind. Side walls are the longer walls running parallel under the gutters (or along the side of a hoop house), often designed to roll up for ventilation.

What are the four types of subirrigation?

Capillary mat, trough, ebb and flow, flood floors

Things to consider about greenhouse building site

site location, level site, drainage and soil quality, obstructions, nearby utilities, road access

Cold frame

a structure used to grow plants that is passively heated

High tunnel

a square or semicircular structure made of a frame and a covering, such as a plastic film

Hotbed

a structure consisting of four walls and a glass or plastic top. Has additional heat.

Horizontal air fan

fans mounted overhead around the greenhouse to gently guide warm air in a circulating pattern.

Perforated convection tubes

plastic tubes with small tubes that release the air that is blown down the tube.

Aspirated thermostat

a device that measures temperature and has a small fan attached to blow the air across the temperature sensor.

Fogger

atomize water into tiny droplets, smaller than mist.