ENERGY Flashcards
The long direction of the building should be oriented along which axis? Name two reasons.
The east-west axis. To minimize the intense East and West solar radiation while taking advantage of the heating potential of south facing surfaces in the winter.
What are the (7) main factors for energy-efficient building orientation?
Heat gain, protection from overheating, daylighting, photovoltaic and solar heating panels, use of beneficial cooling breezes, protection from cold winds, and site topography.
Considering slightly lower morning temperatures, you should just slightly orient a building in what direction off of South? And by approx. how many degrees?
The long direction pointing south can be slightly to the east, approx. 15°.
In cold climates a building entrance should be located on what side to avoid winter winds?
The Leeward side
In temperate climates entrances should be located on what side to make them more inviting and to capitalize on the natural snow – melting affects of the sun?
The south side
In hot climates how should you orient the long side of the building and why?
The long side can be oriented to catch cooling breezes
Minimizing surface area as a way to conserve energy works best in what kind of climates?
Cold climates
Name three advantages of a long rectangular buildings.
The long face can be oriented toward the south for solar heating, and to minimize heat again on the east and west. Long, thin buildings also make it easier to utilize daylighting and to capture winds for natural ventilation.
What is an external load dominated building and what are its characteristics?
A building whose energy use is determined mainly by heat loss or heat again through the exterior envelope. It has few occupants per-unit area and a small amount of heat game from lighting, equipment, and people. This includes houses, apartments, condominiums, and warehouses.
What is an internal load dominated building and what are some of its characteristics?
Hey building his energy use is driven by a high heat again from occupants, lighting, and equipment. Examples include office buildings, hospitals, retail stores, schools, and laboratories.
What side of the building should you place a deciduous tree on?
Southside
How close does a row of trees need to be to a building to reduce wind velocity?
About 10 times the height of the tree away
What kind of shading device is most commonly best for south facing facades?
Moderate overhangs or horizontal louvers
What kind of shading device is most commonly best for east and west facing facades?
Vertical louvers
A row of trees of a certain height will reduce the velocity of wind by…
30% to 40% at a distance about 5 times the trees
What are 3 preconditions for better earth sheltering?
- Natural slope to the land (less earth moving)
- Granular soil, i.e. Not clay as it doesn’t drain well and can expand with moisture.
- Groundwater level must be below the building
What are 3 precautions to take when designing an earth sheltered building?
- Extra care in waterproofing the underground portions
- The insulation you do use must be designed carefully to avoid condensation on inside walls in a humid environment
- Plan for adequate ventilation with the fact that there will be less windows
Name 9 pros of a green roof.
- Conserving energy by reducing cooling and heating loads
- Reducing storm runoff
- Absorbing carbon dioxide
- Reducing ambient air temperatures
- Filtering the air and binding dust particles
- Reducing heat island effect
- Protecting roof from ultraviolet light degradation, temp extremes, wind and hail
- Adding acoustical insulation
- Aesthetic appeal!
What are the 2 major types of green roofs? Describe.
Extensive and intensive. Extensive uses soil less than 6in. for meadow grasses, sedums, herbs perennials. Intensive uses deeper soils and supports complex plantings and shrubs.
6 steps to making a green roof
- Waterproofing over roof structure
- Root barrier (if necessary) placed over the waterproofing
- Insulation over the root barrier, helping to keep water in the growth media from taking heat during the winter
- Drainage layer.
- Filter fabric
- Growth medium from 2-12 inches
Green roofs should be sloped between what and what percent?
1.5 min, 30 max.
You get a LEED credit if your green covers what percent of the total roof
50
A revolving door is a kind of what?
An air lock
Very generally, how many years does it take to recover the cost spent on insulation, weatherstripping, and caulking?
A few
Name nine types of insulation
Fiberglass, mineral wool, polystyrene, polyisocyaanurate, polyurethane, cellulose, cementitious foam, autoclaved aerated concrete, strop panels, straw – bale construction, plastic fiber
Name four types of available insulation in form.
Loose fill, batt, rigid foam boards, spray on foam, or included in other construction assemblies like structural insulated panels
Most insulation types require what to be effective?
A vapor barrier
What are two things that should not be used in insulation?
Chlorofluorocarbons or hydrochlorofluorocarbons
What does superinsulation mean?
Superinsulation is the technique of providing higher levels of insulation than would normally be used, sealing cracks, and preventing thermal bridges
What do you sometimes have to do in order to super insulate?
Make a thicker wall
What is transparent insulation?
A thick layer of polycarbonate honeycomb material, acrylic foam, or fiberglass sandwiched between layers of glazing
What is movable insulation?
This is when you remove insulation during sunlight hours and replace it at night or during cloudy weather to prevent heat loss. Typically used on windows. Go down shutters, insulated shades, swinging panels of insulation, expanded polystyrene beads blown between panes of glass.
What are the three awesome things that an air barrier does?
- Conserves energy by conditioning unwanted infiltrating air until it meets indoor air requirements.
- Blocking out infiltrating air which may contain pollutants
- Controlling air movement and helping to minimize migration of moisture
What does wind pressure do?
Wind pressure puts positive pressure on the windward side of the building and negative pressure at the corners and on the Leeward side.
What is stack pressure?
A difference in pressure at the top and bottom of the building due to temperature differences.
What is fan pressure?
Fan pressure is the pressure created by an HVAC system
Name five materials that have n low enough air permeability to be used as air barriers
Gypsum board, foil-faced urethane insulation, glass, metal, urethane foam, modified bitumous self-adhering membranes, cement board
What is the difference between an air barrier and a vapor barrier?
An air barrier is part of the envelope that controls the movement of air in and out. A vapor barrier prevents water from moving out of the building in cold climates and into a building in hot humid climates