SPD Ballast - Ch 29 ENERGY EFFICIENCY AND ALTERNATIVE ENERGY SOURCES Flashcards
External Load Dominated Buildings (Also known as Skin-load Dominated Buildings)
are those whose energy use is determined mainly by heat loss or gain through the exterior envelope or skin.Types of buildings few occupants per unit area and a small amount of heat gain from lighting, equipment, and people. Examples houses, apartments, condominiums, and warehouse.
Internal Load Dominated Buildings
are those whose energy use is driven by high heat gain from occupants, lighting, and equipment. Ex types of buildings office buildings, hospitals, retail stores, schools, and laboratories.
GREEN ROOF, also called a vegetated roof cover, garden roof, or eco-roof
is a thin layer of vegetation installed on the top of a roof
Extensive Green Roofs
Use soil less than 6in. deep supporting meadow grasses, sedums, herbs, and perennials.
Intensive Green Roofs
Use thicker soil and support complex landscapes, including shrubs and small trees along with ponds and fountains.
Superinsulation
providing higher levels of insulation than normally used, tightly sealing all joints and cracks, and preventing any thermal bridges between the outside and inside, such as through studs.
Transparent Insulation
Used to admit light while providing a high degree of insulation. It consists of a thick layer of polycarbonate honeycomb material, acrylic foam, or fiber-glass sandwiched between layers of glazing.
Moveable Insulation
Typically used on windows that provide passive solar heating. The insulation is removed during sunlight hours and replaced at night or during cloudy weather to prevent heat loss. This type of insulation can be manually operated, power operated, or set to work automatically. Types include: roll-down shutters, insulated shades, swinging panels of insulation, and expanded polystyrene beads blown between panes of glass.
Air Barrier
part of a building envelope system that controls the movement of air into and out of a building (infiltration and exfiltration).
Wind Pressure
puts positive pressure on the side of the building it is hitting and negative pressure at the corners and on the lee side.
Stack Pressure
Is caused by a difference in atmospheric pressure at the top and bottom of a building due to temperature differences.
Fan Pressure
is caused by the pressure created by the HVAC system.
Low-emittance glass (Low-e glass)
This is double glazing with a thin film or coating placed somewhere in the glazing cavity.
Spectrally Selective Glazing
Transmits a high proportion of the visible solar spectrum while blocking heat from the infrared portion of the spectrum, up to 80%.
Super Windows
are glazing units that combine two low-e coatings with gas-filled cavities between three layers of glass.
Switchable Glazings
are chromogenic fenestration products that change their characteristics based on particular environmental conditions or through human intervention.
Electrochromic Glazing
consists of a multilayered thin film applied to glass, that changes continuously from dark to clear as low-voltage electrical current is applied.
Photochromic Glazing
darkens under the direct action of sunlight, in the same way that some sunglasses do.
Thermochromic Glazing
changes darkness in response to temperature.
Transition-Metal Hydride Electrochromics
make it possible to have a Glazing material that changes from transparent to reflective.
Dynamic Buffer Zone
is when a new outer layer of glazing is built around an existing building.
Daylight Factor (DF)
Is the percentage ratio, of the indoor illuminance (at a point on a horizontal surface) to the unobstructed exterior horizontal illuminance. Direct sunlight excluded.
Effective Aperture
combines the variables of light transmittance (VLT) and window-to-wall (WWR) ratio.
(VLT) Visible Light Transmittance
is the percentage of light that passes through a glazing material.
(WWR) Window-to Wall Ratio
is the net glazing area in a room divided by the gross exterior wall area.
Light Shelf
horizontal surface placed above eye level that reflects direct daylight onto the ceiling while shading the lower portions of the window and the interior of the room.
Light Pipes
are round/square tubes with highly reflective interior coatings that extend from the roof to the space to be lighted.
Declination Angle (Declination)
The north-south axis of the earth is titled at an angle of 23.5-degrees relative to the north-south axis of the sun.
Passive Solar Energy System
solar energy is collected, stored, and distributed without the use of mechanical equipment.
Direct Gain Systems
collect heat through south-facing glass and store the heat in high-mass materials such as concrete floors, masonry walls, tile, stone, or terrazzo.
Indirect Gain Systems
are similar to direct gain systems except that the thermal mass is not in direct sunlight.
Thermal Storage Wall
is placed directly behind a south facing glass wall and collects solar energy during the day for release at night
Trombe Wall
constructed of masonry with vents at the top and bottom to allow thermocirculation
Phase Change Materials
are used to prevent over heating and wide swings in temperatures that can occur with concrete, masonry and water. Typically eutectic salts that change from a solid to a liquid at a fairly low temperature, around 70F (21C).
Greenhouse Designs
Have large glazed areas on the south side of the building (greenhouse) with a heavy thermal mass wall separating the greenhouse and the remainder of the structure.
Roof Ponds
store heat in large water-filled bags on the roof of a building. In winter during the day, the bags heat up.
Convective Loop Systems
place the solar collector below the space so that air is circulated by natural convection as the warm air rises and cool air falls back to the collector.
Roof Ponds
store heat in large water-filled bags on the roof of a building
Convective Loop Systems
Place the solar collector below the space so that air is circulated by natural convection as the warm air rises and cool air falls back to the collector
Active Solar Energy Systems
Use pumps, fans, ducts, pipes, and other mechanical equipment to collect, store, and distribute solar energy.
Flat-Plate Collector
A network of pipes located on an absorptive black surface with low emissivity below a covering of glass or plastic.
Focusing Collector
Parabolic-shaped reflectors that focus the incoming radiation to a single pipe that carries the heat-transfer medium.
[GSHP] Ground-Source Heat Pumps
Are electrically powered systems that work by either extracting heat from the ground in winter or giving off excess heat to the ground in summer.
Photovoltaics
Direct conversion of sunlight into electricity
