Green Building Systems exam 1

thermal barrier

(insulation) a boundary to heat flow this and air barrier must be complete and in contact with each other spray foam insulation works as both

the amount of water vapor that diffuses through a building is affected by the following factors:

1. chemical composition of building materials 2. thickness of building materials 3. absolute humidity on each side of the building assembly

Environmentally sensitive lands

1. land within the 100 year floodplain as defined by federal emergency management Agency 2. land that is specifically identified as habitat for any species on federal or state threatened or endangered lists 3. land within 100 feet of any body of water 4. areas identified as of special concert by state or local jurisdiction 5. land that was public parkland 6. land identified by state natural resources conservation services soil surveys to contain "prime soils" "unique soils" "soils of state significance"

BTU

british thermal units, heat. the amount of heat required to raise one pound of water one degree F

grayfield development

previously developed and underutilized real estate assets or land

brownfield

previously developed sites contaminated by hazardous waste or pollution that require environmental remediation prior to reuse.

pre plumbing

process of installing plumbing distribution systems during construction to meet future technology need

R-value

quantitative measure of the resistance to heat flow or conductivity states how much heat transmits through 1 square foot of surface in one hour with a 1 degree F difference between opposite surfaces (?) R value = btu/hr/oF/ft^2 R values can be added together to get a total R value insulation high R value

infill development

sites surrounded by existing or planned development immediately adjacent to the property boundaries

greenfield development

sites that are previously undeveloped, forest or farmland, should be avoided

edge development

sites with 25 percent or more of the property boundary adjacent to existing development.

grain

small unit of weight, one pound is 7000 grains.

best management practices (BMP)

strategies for keeping soil and other pollutants out of streams and lakes, BMPs are designed to protect water quality and prevent new pollution

sun tempered design

strategy in which the house and most of the glazing are oriented toward the south. passive solar design.

solar orientation

the cardinal direction in which the home and its glazing faces placing a house with a large wall of unshaded windows facing west will significantly increase the cooling load, requiring a larger HVAC system than if the house had been designed to reduce or shade those windows. can save money and energy

convective loop

the continuous circulation of air (or another liquid) in an enclosed space as it is heated and cooled

stack effect

the draft established in a building from air infiltrating low and exfiltrating high problem: in summer, the stack effect can actually reverse as hot attic air enters the home and forces relatively cool, air conditioned air out at the bottom

stormwater

the flow of water that results from precipitation following rainfall or as a result of snowmelt. water accumulates debris, chemicals, sediment, automotive fluids, or other pollutants before its discharged into streams and other rivers.

relative humidity (RH)

the percentage of the maximum moisture that the air can hold at a specific temperature recommended RH levels for indoor air quality and health range from 40-60%

passive solar design

the practice of designing a home to utilize the suns energy for heating and cooling

air sealing

the process of reducing air leakage into and out of a home typically accomplished by applying some combination of caulk, spray foam, weather stripping and other air IMPERMEABLE materials

perm rating

the rate of water vapor passage through a material under fixed condition

building envelope (thermal envelope)

the separation between the interior and the exterior environments of a building, consisting of an air barrier and thermal barrier that are continuous and in contact the dividing line between conditioned and unconditioned space in a house includes the exterior walls, ceilings, and floors, however many homes are built with conditioned or semi conditioned attics, basements, and crawl spaces where the roof and foundation walls and floor serve as the building envelope Consists of 2 components: thermal barrier, and air barrier

building science

the study of the interaction of building systems and components, occupants, and the surrounding environment, focusing on the flows of heat, air, and moisture

dew point

the temp at which vapor condenses into water droplets

dry bulb temperature

the temp of air indicated on an ordinary thermometer and does not account for the effects of humidity

wet-bulb temperature

the temperature recorded by either a sling thermometer or an aspirating psychrometer(takes into account everything)

convection

the transfer of heat through a fluid

glazing

the transparent part of a wall or door assembly that is usually made of glass south facing windows allow the winter sun's energy to penetrate further into the home, which provides heating and illumination benefits.

infiltration

the uncontrolled process byu which air or water flows through the building envelope into the home

conduction

transfer of heat from one solid to another through contact

permeance levels

vapor impermeable: .1 perm or less vapor semi-impermeable: between .1 and 1 perm vapor semi-permeable: between 1 and 10 perms vapor permeable: greater than 10 perms

integrated design

a collaborative method for designing buildings that emphasizes the development of a holistic design

Charrette

a design meeting consisting of all project stakeholders, held in the early parts of the design process and contains every discipline.

psychrometric chart

a graph showing the relationship between a particular sample of air's dew point temperature, dry bulb temperature, wet bulb temperature, humidity ratio, and relative humidity. the physical properties of moist air at a constant pressure.

Vapor diffusion retarder (VDR)

a material that reduces the rate at which water vapor can move through a material recommended on the exterior in warm humid climates and on the interior in cold climates, and not at all in mixed climates. AC with cold areas can cause condensation and create mold and problems

heating degree day HDD

a measure of how cold a location is over a period of time relative to a base temp, most commonly specified as 65 degrees

cooling degree day CDD

a measure of how warm a location is over a period of time relative to a base temp, most commonly specified as 65 degrees

slope disturbance

a process of destabilizing a slope through grading and site development

air barrier

a protective, air-resistant material that controls air leakage into and out of the building envelope made up of drywall, hardboard panels, foam board, and house wrap, all of which must be installed using sealants, tape, and caulk at joints between panels or sheets and around gaps at windows, doors, and other openings

low emissivity (low E)

a surface that radiates, or emits, low levels of radiant energy

exfiltration

air flow outward through a wall, building envelope, window, or other material

ERV/HRV

energy recovery ventilators or heat recovery ventilators, very efficient heat exchanger.

radiation

heat energy transferred through the air

spot ventilation

in bathrooms or kitchen fans

pre wiring `

is the process of installing electric wiring during construction to meet future technology demands.

energy

measurable quantity of heat, work, or lighT

whole house ventilation

mechanical ventilation. air handler and duct system, a separate fan and duct system, or a combination of the 2.