Air changes per hour are a measure of how many times the air within a defined space (normally a room or house) is replaced. Without sufficient fresh air exchange, moisture is trapped in a room/home/building. Molds can flourish. Other allergens and excessive dangerous gases (e.g. carbon monoxide, carbon dioxide, urea formaldehyde) can remain in the home. Stale air is unhealthy and, since humans and pets add to it by breathing, sweating, washing, showering and drying, ventilation is required to increase the number of times the air in the home is replaced with outside fresh air. The number of air changes per hour was less of a problem before air sealing came into play, because construction practices and products were not geared to energy efficiency.
Any substance in air that could, in high enough concentration, harm man, other animals, vegetation or material. Pollutants may include almost any natural or artificial composition of matter capable of being airborne. They may be in the form of solid particles, liquid droplets, gases or any combination thereof.
Energy from a source other than the conventional fossil-fuel sources of oil, natural gas and coal. Some examples are geothermal wind, running water, solar and nuclear. Also referred to as “alternative fuel.”
AFUE is a measure of the seasonal or annual efficiency of an oil- or gas-fired heat system under laboratory testing conditions. It is used to compare one system to another under like conditions.
American Society of Heating, Refrigeration and Air Conditioning Engineers.
Waste material composed primarily of constituent parts that occur naturally, are able to be decomposed by bacteria or fungi, and are absorbed into the ecosystem. Wood, for example, is biodegradable, while plastics are not.
British Thermal Unit, the amount of energy required to raise the temperature of one pound of water one degree Fahrenheit. A “Therm” is 100,000 BTU’s.
The exterior enclosure of a building’s construction: the walls, windows, roof and floor. Also referred to as “building shell.” Tightening the building envelope is an increasing trend essential to improving the energy-efficient of structures.
Stable, artificially created chemical compounds containing carbon, chlorine, fluorine and sometimes hydrogen. Chlorofluorocarbons, used primarily to facilitate cooling in refrigerators and air conditioners, deplete the stratospheric ozone layer that protects the earth and its inhabitants from excessive ultraviolet radiation.
Cubic feet per minute is a common measure of airflow.
A process to carefully dismantle or remove useable materials from structures as an alternative to demolition. It maximizes the recovery of valuable building materials for reuse and recycling and minimizes the amount of waste entering landfills. Deconstruction options may include reusing the entire building by remodeling, moving the structure to a new location or taking the building apart to reuse lumber, windows, doors, and other materials.
Embodied energy is defined as the commercial energy (fossil fuels, nuclear, etc) that was used in the work to make any product, bring it to market, and dispose of it. Embodied energy is an accounting methodology which aims to find the sum total of the energy necessary for an entire product lifecycle. This lifecycle includes raw material extraction, transport, manufacture, assembly, installation, disassembly, deconstruction and/or decomposition.
ERV is the process of using the energy contained in the air of a building to treat and condition the incoming outdoor air in residential and commercial systems. During the warmer seasons the system will cool and dehumidify). It will humidify and heat air in the cooler seasons. Energy recovery improves indoor air quality and reduces demand on HVAC equipment. See HRV.
A voluntary labeling program designed by the Environmental Protective Agency to promote energy-efficient building practice and products and reduce carbon monoxide emissions. Homes built to national Energy Star requirements are at least 30% more efficient than the 1995 Model Energy Code.
Engineered wood, also called composite wood, man-made wood, or manufactured board; includes a range of derivative wood products which are manufactured by binding the strands, particles and fiber of wood, together with adhesive to form composite material. These products are engineered to precise design specifications tested to meet national or international standards. Plywood is sometimes called the original engineered wood.
This is the environmental impact determined by the amount of depletable raw materials and nonrenewable resources consumed to make products (including structures), and the quantity of wastes and emissions generated in the process.
Products that have a lesser or reduced effect on human health and the environment when compared with competing products that serve the same purpose. The product comparison may consider raw materials acquisition, production, manufacturing, packaging, distribution, reuse, operation, maintenance, or disposal. E.g., “paper vs. plastic.”
It is a fine, glass-like powder recovered from the gases of burning coal during the production of electricity. When mixed with lime and water fly ash forms a cement-like compound with properties very similar to that of Portland cement. Concrete made with fly ash is denser, resulting in a tighter, smoother surface with less bleeding. Fly Ash concrete offers a distinct architectural benefit with improved textural consistency and sharper detail.
Its purpose is to coordinate the development of forest management standards throughout the different bio-geographic regions of the U.S., to provide public information about certification and FSC, and to work with certification organizations to promote FSC certification in the U.S.
A general contractor is responsible for the day-to-day oversight of a construction site, management of vendors and trades, and communication of information to involved parties throughout the course of a building project. Read More about General Contractor on Wikipedia…
A home heating and cooling system that draws upon the relatively constant temperatures beneath the ground to condition the inside of a structure. Geothermal power is considered sustainable because the heat extraction is small compared to the Earth’s heat content.
Disinformation disseminated by an organization to present an environmentally responsible public image. For example, a product lauded for its partial recycled content might not be “green” because it still contains undesirable contents or places excessive demands on energy consumption in its manufacture, packaging and distribution.
An HRV, also known as Mechanical ventilation heat recovery, or MVHR, is an energy recovery system, using equipment known as a heat recovery ventilator, heat exchanger, air exchanger or air-to-air exchanger. HRV provides fresh air and improved climate control, while also saving energy by reducing the heating (or cooling) requirements. See also ERV.
ASHRAE defines acceptable indoor air quality as air in which there are no known contaminants at harmful concentration levels.
Foam boards or blocks containing concrete. Used in new construction foundation walls, the insulation is built into a home’s walls, thus creating high thermal resistance
Made of fiberglass, mineral (rock or slag), wool or plastic fibers. Very commonly used between studs, joists and beams.
Made of poly-plastics foam beads or liquid foam. Used in walls, including foundation walls, it has ten times the insulating value of concrete.
Made of poly-plastics. Used in walls, foundations, floors and ceilings, it has high insulating value for relatively little thickness.
Made of cellulose, fiberglass, mineral (rock or slag) or wool. Commonly blown or poured into enclosed existing walls and unfinished attic floors.
Made of foil-faced kraft paper, plastic film, polyethylene bubbles or cardboard. Used in unfinished walls, ceilings and floors.
Made of fiberglass, mineral (rock or slag) or wool. Used for ducts in unconditioned spaces because it can withstand high temperatures.
Made of poly-plastics. Used in enclosed existing walls, open new wall cavities, and unfinished attic floors, it is good for insulating irregularly shaped areas and around obstructions. See: Insulation, Spray Foamed, Closed Cell.
Made of poly-plastics. Used in enclosed existing walls, open new wall cavities, and unfinished attic floors, it is good for insulating irregularly shaped areas and around obstructions. The advantages of the closed-cell foam compared to open-cell foam include its strength, higher R-value, and greater resistance to the leakage of air or water vapor. The disadvantage of the closed-cell foam is that it is denser, requiring more material, and therefore, more expense. Even though it has a better R-value, the cost per R is still higher than open-cell foam. The choice of foam should be based on the requirements for the other characteristics: strength, vapor control, available space, etc.
It is any material used to prevent or reduced heat transfer. The effectiveness of an insulating material is measured by its R-value.
LEED (Leadership in Energy and Environmental Design) is a self-assessing system designed for rating new and existing commercial, institutional, and residential buildings. It evaluates environmental performance from a “whole building” perspective over a building’s life cycle, providing a definitive standard for what constitutes a green building. See USGBC
A coating on widow glazing that permits most of the sun’s short-wave light to enter while blocking up to 90% of the long-wave light. Low-emissive coatings raise a window’s R-value and reduces its U-factor.
MDF’s are engineered product formed by breaking down hardwood or softwood residuals into fibers, combining them with wax and a resin binder. Panels are formed by applying high temperature and pressure. MDF is denser than plywood, but can be used as a building material similar in application to plywood. It is stronger and much more dense than conventional particleboard.
Standards established by the EPA that apply to outdoor air throughout the country.
A resource that cannot be replaced in the environment because it forms at a rate far slower than its consumption.
The New York State Energy Research and Development Agency. It promotes energy efficiency while protecting the environment through electric service delivery, building and transportation, consumer education and other programs.
OSB’s are engineered wood products used as an alternative to plywood. It is composed of wood byproducts that would otherwise be waste.
A naturally occurring, highly reactive, irritating gas comprising triatomic oxygen formed by recombination of oxygen in the presence of ultraviolet radiation. This gas builds up in the lower atmosphere as smog pollution, while in the upper atmosphere it forms a protective layer that shields the earth and its inhabitants from excessive exposure to damaging ultraviolet radiation.
The protective layer in the atmosphere, about 12-15 miles above sea level, that absorbs some of the sun’s ultraviolet rays, thereby reducing the amount of potentially harmful radiation that reaches the earth’s surface.
Photovoltaics are used for direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity. Solar panels are used to collect the light.
A product composition that contains some percentage of material that has been reclaimed from the same or another end use at the end of its former, useful life.
Industrial manufacturing scrap or waste; also called pre-consumer material,
A measure of effectiveness in stopping heat transfer, most often used to indicate the effectiveness of insulation. The higher the number the less heat transfer there is. The R-value is the reverse of U-factor.
Restoration of materials found in the waste stream to a beneficial use that may be other than the original use.
Process by which materials that would otherwise become solid waste are collected, separated or processed and returned to the economic mainstream to be reused in the form of raw materials or finished goods.
A resource that can be replenished at a rate equal to or greater than its rate of depletion; i.e., solar, wind, geothermal and biomass resources.
SEER is a rating system for cooling equipment. The national efficiency standard for air conditioners and heat pumps is currently 12.0.
A building whose occupants experience acute health and/or comfort affects that appear to be linked to time spent therein, but where no specific illness or cause can be identified. Complaints may be localized in a particular room or zone, or may spread throughout the building and may abate on leaving the building.
SIPs are high performance building panels used in floors, walls, and roofs for residential and light commercial buildings. The panels are typically made by sandwiching a core of rigid foam insulation between two structural skins of oriented strand board (OSB). Other skin material may be used for specific purposes. SIPs are manufactured under factory-controlled conditions and can be custom designed for each purpose. Often used in post and beam homes, the result is a building system that is extremely strong, energy efficient and cost effective.
Practices that would ensure the continued viability of a product or practice well into the future.
The HERS Index is a means of scoring energy efficiency. It compares a given home to one built per the 2006 International Energy Conservation Code. A Code-built home has a HERS index of 100 and a home that uses no energy or produces all the energy it uses has a HERS index of zero.
The total change on the environment, whether adverse or beneficial, wholly or partially resulting from human activity, industry or natural disasters.
The rate at which at which an object conducts non-solar heat. It is the inverse of R-value. The lower the U-factor number, the better heat will be retained during cold weather.
The United States’ foremost coalition of leaders from across the building industry working to promote buildings that are environmentally responsible, profitable, and healthy places to live and work.
VOC’s are emitted as gases from certain solids or liquids. VOC’s include a variety of chemicals, some of which may have short- and long-term adverse health effects. Concentrations of many VOC’s are consistently higher indoors (up to ten times higher) than outdoors. VOC’s are emitted by a wide array of products numbering in the thousands. Examples include: fuels, paints and lacquers, paint strippers, cleaning supplies, pesticides, building materials, carpeting and furnishings, office equipment such as copiers and printers, graphics and craft materials including glues and adhesives, permanent markers, and photographic solutions.
A measure of electric power.