Formative Assessment 1 Flashcards
What makes a controlled environment in horticulture?
A protected and enclosed environment (i.e. Greenhouses, warehouses etc.)
What is a greenhouse?
A structure covered with a transparent material that admits natural light.
What are important things to consider when locating a greenhouse?
Room for expansion, topography and microclimates, land-use predictions
What climate factors are important to consider when placing a greenhouse?
Fog, air pollution/quality, frost pockets (high surrounding elevation), areas with high winds, hail
What economic factors are important to consider when placing a greenhouse?
Labor supply, access to roads (shipping), water supply/quality
Why is orientation important when placing a greenhouse?
A greenhouse needs optimal, uniform lighting for most hours a day
What is incident light?
The light that hits the surface of a plant
How can incident light behave upon hitting the surface of a plant?
It can be reflected, transmitted (pass through), or absorbed (photosynthesis)
At what angle of incident is light transmission most optimal?
0 degrees
At what angle of incident is light reflection most prominent?
The closer it is to 90 degrees
What direction should the ridge of a greenhouse run?
North to south
What factors are important when considering land-use predictions around a greenhouse?
Urbanization, expansion of the greenhouse operation, product movement
What factors should be considered when selecting a glazing for a greenhouse?
Light transmission, thermal qualities (expansion/contraction, heat retention, thermal radiation), strength and weight (structural support, shattering resistance, tear resistance)
What are examples dead loads of weight on a greenhouse roof?
Frames, glazings, heaters, lights, etc.
What are examples live loads of weight on a greenhouse roof?
Repair persons, hanging baskets, nothing exceeding 15lbs/sqft.
What are other forces to consider when roofing a greenhouse?
Snow load, wind load, foundations, hurricanes, earthquakes
Define thermostatics
The science of dealing with the equilibrium of heat, including heat transfers and thermal properties of materials
What is convection?
The movement of molecules transferring heat energy from one place to another
What is conduction?
The transference of heat through collision
What is radiation?
The electrical transfer of heat
