Green Glossary
General Terms -
Windows -
Heating and Cooling -
Air Quality -
Insulation
Water -
Electric / Lighting -
Solar
Water - Electric / Lighting - Solar
General Terms:
Alternative Energy - Energy from a source other than the conventional fossil-fuel sources of oil, natural gas and coal (i.e., wind, running water, the sun). Also referred to as "alternative fuel."
Certified or Certification - A process by which an independent agent verifies that the claims made by a product service, etc. are valid. Many certification programs exist through which products meeting independent standards may use a label or logo to indicate their claims have been verified.
Energy Efficient - Refers to the process of maximizing the ratio between energy use and product output.
Energy Efficiency - Ways and technology that can reduce the amount of electricity or fuel used to do the same work. Such as keeping a house warm using less energy.
Energy Star - A program developed by the Environmental Protection Agency (EPA) in order to reduce the nation's energy consumption. ENERGYSTAR® qualified heating equipment can be up to 15 percent more efficient than standard models. Energy Star-qualified cooling equipment can be up to 7 percent more efficient than minimum-standard equipment.
Energy Star Rating - Refers to the process of maximizing the ratio between energy use and product output.
Green Design - A design, usually architectural, conforming to environmentally sound principles of building, material and energy use. A green building, for example, might make use of solar panels, skylights and recycled building materials.
H.E.R.S. - For a new home, HERS, Inc.™ typically starts with a review of the plans and recommendations for making the home more efficient, affordable and comfortable. Intermediate inspections are provided during construction and a final verification inspection and commissioning of the house is provided at completion. Testing includes blower door testing for whole house leakage and duct leakage testing to measure duct leakage to the outside. With an existing house, going green should start with a whole house, diagnostic energy audit that looks at all aspects of the house ”as a system.” An audit includes prioritized recommendations with estimated dollar savings.
LEED - Refers to the U.S. Green Building Council’s Leadership in Energy and Environmental Design. The Green Building Rating System has become an accepted benchmark for the design as well as the construction and operation of green buildings and homes. The system contains five critical areas; which are water savings, sustainable site development, materials selection, energy efficiency and indoor environmental quality.
Renewable Energy - Refers to the use of natural resources such as wind, sunlight, earth heat and tides in order to create a separate form of energy like electricity.
Sustainability - Meeting the needs of the present without compromising the ability of future generations to meet their needs.
Windows
Absorptance - The ratio of radiant energy absorbed to total incident radiant energy in a glazing system.
Air infiltration - The amount of air leaking in and out of a building through cracks in walls, windows and doors.
Air-leakage rating - A measure of the rate of air-leakage around a window, door, or skylight in the presence of a specific pressure difference. It is expressed in units of cubic feet per minute per square foot of frame area (cfm/sq ft). The lower a window's air-leakage rating, the better its air tightness.
Argon gas windows - Argon is inert and safe gas that occur naturally in the atmosphere. They are invisible and heavier than air, thus they are denser than normal air. These gases are added between the two panes of glass as they are manufactured into their sealed glass units. Once these gases are installed into a window, they are denser than regular air.
Condensation - The deposit of water vapor from the air on any cold surface whose temperature is below the dew point, such as a cold window glass or frame that is exposed to humid indoor air.
Convection - A heat transfer process involving motion in a fluid (such as air) caused by the difference in density of the fluid and the action of gravity. Convection affects heat transfer from the glass surface to room air, and between two panes of glass.
Double glazing - In general, two thicknesses of glass separated by an air space within an opening to improve insulation against heat transfer and/or sound transmission. In factory-made double glazing units, the air between the glass sheets is thoroughly dried and the space is sealed airtight, eliminating possible condensation and providing superior insulating properties.
Emittance - The ratio of the radiant flux emitted by a specimen to that emitted by a blackbody at the same temperature and under the same conditions.
Insulating glass - Two or more pieces of glass spaced apart and hermetically sealed to form a single glazed unit with one or more air spaces in between. Also called double glazing.
Insulating value - (See U-factor)
Low E-Windows - Low emissivity windows reflect heat, not light, keeping spaces warmer in winter and cooler in summer.
Low-emittance (Low-E) coating - Microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a window or skylight glazing surface primarily to reduce the U-factor by suppressing radiative heat flow. A typical type of low-E coating is transparent to the solar spectrum (visible light and short-wave infrared radiation) and reflective of long-wave infrared radiation.
Polyvinylchloride (PVC) - An extruded or molded plastic material used for window framing and as a thermal barrier for aluminum windows.
Pyrolytic low-E - A low- E coating which typically uses tin oxide with some additives deposited directly onto a glass surface while it is still hot. The result is a baked-on surface layer that is hard and durable and thus sometimes referred to as a "hard coat." Pyrolytic coatings are typically used in insulated glass units with the low-E surface inside the sealed air space, but can also be applied to single-pane glass and separate storm windows.
R-value - A measure of the resistance of a glazing material or fenestration assembly to heat flow. It is the inverse of the U-factor (R = 1/U) and is expressed in units of hr-sq ft-°F/Btu. A high-R-value window has a greater resistance to heat flow and a higher insulating value than one with a low R-value.
Reflective glass - Window glass coated to reflect radiation striking the surface of the glass.
Solar heat gain coefficient (SHGC) - The fraction of solar radiation admitted through a window or skylight, both directly transmitted, and absorbed and subsequently released inward. The solar heat gain coefficient has replaced the shading coefficient as the standard indicator of a window's shading ability. It is expressed as a number between 0 and 1. The lower a window's solar heat gain coefficient, the less solar heat it transmits, and the greater its shading ability.
Thermal expansion - Change in dimension of a material as a result of temperature change.
Thermal mass - Mass in a building (furnishings or structure) that is used to absorb solar gain during the day and release the heat as the space cools in the evening.
U-factor (U-value) - A measure of the rate of non-solar heat loss or gain through a material or assembly. It is expressed in units of Btu/hr-sq ft-°F (US) The U-factor may be expressed for the glass alone or the entire window, which includes the effect of the frame and the spacer materials. The lower the U-factor, the greater a window's resistance to heat flow and the better its insulating value.
Ultraviolet light (UV) - The invisible rays of the spectrum that are outside of the visible spectrum at its short-wavelength violet end. Ultraviolet rays are found in everyday sunlight and can cause fading of paint finishes, carpets, and fabrics.
Weatherstripping - A strip of resilient material for covering the joint between the window sash and frame in order to reduce air leaks and prevent water from entering the structure.
Thermal Break - A non-conducting material positioned between metal components of windows to reduce thermal conduction. In building assemblies, a thermal break reduces conductive heat transfer through materials like wood or metal framing studs.
Heating and Cooling
Ambient Air - Open air, surrounding air, or outside air.
Air Handler - The indoor component of your air conditioner or heating system that moves air throughout your home.
British Thermal Unit (BTU) - In scientific terms, it represents the amount of energy required to raise one pound of water one degree Fahrenheit. One BTU is the equivalent of the heat given off by a single wooden kitchen match. For your home, it represents the measure of heat given off when fuel is burned for heating, or the measure of heat extracted from your home for cooling.
Capacity - The output or producing capability of a piece of cooling or heating equipment. Cooling and heating capacity are normally referred to in BTU's.
CFM (Cubic feet per minute) - A standard of airflow measurement. A typical system produces 400 CFM per ton of air conditioning.
Compressor - The heart of an air conditioning or heat pump system. It is part of the outdoor unit that pumps refrigerant. The compressor maintains adequate pressure to cause refrigerant to flow in sufficient quantities in order to meet the cooling requirements of the system and your home.
Condenser Coil or Outdoor Coil - Located in the outdoor unit, the coil dissipates heat from the refrigerant, changing the refrigerant.
Damper - Found in ductwork, this movable plate opens and closes to control airflow. Dampers are used effectively in zoning to regulate airflow to certain rooms.
Dehumidifier - A mechanical device which removes moisture vapor from the air.
Ductwork - Pipes or channels that carry air throughout your home.
Dual fuel heating/cooling system - A dual-fuel heat pump is an electric heat pump and a gas furnace all in one. When the temperature is above 35 degrees or so, the dual-fuel heat pump uses electricity to heat your home as necessary. This type of heat circulates evenly throughout your home, and isn't too dry. When it gets really cold outside (around 35 degrees or lower), the heat pump automatically switches to supplemental gas heat for better efficiency.
ERV (Energy Recovery Ventilators) - Energy recovery ventilation systems provide a controlled way of ventilating a home while minimizing energy loss. They reduce the costs of heating ventilated air in the winter by transferring heat from the warm inside air being exhausted to the fresh (but cold) supply air. In the summer, the inside air cools the warmer supply air to reduce ventilation cooling costs.
Geothermal - Referring to earth heat. This term is commonly used to describe alternative energy sources.
Gross Square Feet (GSF) - The total area occupied by a building when measured from exterior to exterior. This area included all mechanical areas.
HEPA (High Efficiency Particulate Absorbing) filter - A HEPA filter removes particles from the air by trapping them as air flows through.
Heat Recovery Systems - Building mechanical systems that capture waste heat from another system and use it to replace heat that would otherwise come from a primary energy source.
Hydronic HVAC - Water based HVAC
Hydronic System - Refers to a cooling or heating system that uses the circulation of water as a heat transferring medium.
Humidifier - A device that adds moisture to dry/indoor air during winter time and in hot, dry climates.
HVAC - The classic acronym for Heating, Ventilation and Air Conditioning. Today, an HVAC system also includes air cleaning and -moisture control.
Indoor Air Quality (IAQ) - The supply and introduction of adequate air for ventilation and control of airborne contaminants, acceptable temperatures and relative humidity.
Indoor Coil - The other, less visible half of your outdoor unit. It's attached to your furnace or air handler. As indoor air flows across it, heat and moisture are drawn out, leaving air that is cool, comfortable and conditioned.
Indoor/Outdoor System (also Split System) - Refers to a comfort system consisting of components in two locations. Common examples include an outside unit, such as an air conditioner, and an indoor unit, such as a furnace with a coil.
Mastic air duct work Economical water based duct mastic - This is a fiber reinforced and rated for high velocity HVAC Systems. It be used to seal all types of HVAC duct systems including metal, fiberglass, duct board and flex duct. Preferred by residential and commercial duct sealing professionals alike.
MERV - The Minimum Efficiency Reporting Value for air filtration.
Natural Ventilation - The process of supplying and removing air through an indoor space by natural means. There are two types of natural ventilation for buildings: wind driven ventilation and stack ventilation.
Passive Cooling - A building’s structure (or an element of it) is designed to permit increased ventilation and retention of coolness with the intention of minimizing or eliminating the need for mechanical means of cooling.
Passive Ventilation - The introduction and/or removal of air that used both convective air flows resulting form the tendency of warm air to rise and cool air to sink, and takes advantage of prevailing winds.
Programmable Thermostats - A programmable thermostat helps make it easy for you to save by offering four pre-programmed settings to regulate your home's temperature in both summer and winter - when you are home, asleep, or away.
SEER - Seasonal Energy Efficiency Ratio, a rating that measures the cooling efficiency of a heat pump or air conditioner. The higher the number, the more efficient the unit.
Thermostat - A temperature-control device, typically found on a wall inside the home. It consists of a series of sensors and relays that monitor and control the functions of a heating and cooling system.
Ton - unit of measurement used for determining cooling capacity. One ton is the equivalent of 12,000 BTU's per hour.
Variable-Speed motor - The fan motor inside higher-efficiency indoor and outdoor units is designed to change its speed based on your home's heating and air conditioning requirements. Working in conjunction with your thermostat, it keeps the appropriate-temperature air (e.g., warm air on cold days) circulating throughout your home, reducing temperature variances. The variable-speed motor also increases dehumidification and is quiet because it runs at a lower speed most of the time.
Air Quality
Air Exchange Rate - The rate at which outside air replaces indoor air in a space. Expressed in one of two ways: the number of changes of outside air per unit of time air changes per hour (ACH); or the rate at which a volume of outside air enters per unit of time - cubic feet per minute (cfm).
Biological Contaminants - Agents derived from, or that are, living organisms (e.g., viruses, bacteria, fungi, and mammal and bird antigens) that can be inhaled and can cause many types of health effects including allergic reactions, respiratory disorders, hypersensitivity diseases, and infectious diseases. Also referred to as "microbiologicals" or "microbials."
Exhaust ventilation - Mechanical removal of air from a portion of a building (e.g., piece of equipment, room, or general area).
Indoor Air Quality (IAQ) - Pollution from gases or particles released into the air is the primary cause of indoor air quality problems. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions.
Infiltration - Outside air that enters a structure through openings or cracks in the construction materials, especially windows and doors. "Design" infiltration in residences can range from one-half air change to three air changes per hour, depending on how well the houses are constructed, caulked, or weather-stripped. Average air changes over the heating season are lower. Infiltration is a major area of home heat loss.
Low-VOC - A term referring to reduced amounts of volatile organic compounds (VOCs) in paint and finishes Low-VOC paints do not off-gas as much as conventional paints and contain less toxins that are harmful to the environment.
Mechanically ventilated crawlspace system - A system designed to increase ventilation within a crawlspace, achieve higher air pressure in the crawlspace relative to air pressure in the soil beneath the crawlspace, or achieve lower air pressure in the crawlspace relative to air pressure in the living spaces, by use of a fan.
Outdoor air supply - Air brought into a building from the outdoors (often through the ventilation system) that has not been previously circulated through the system. Also known as "Make-Up Air."
Ventilation rate - The rate at which outdoor air enters and leaves a building. Expressed in one of two ways: the number of changes of outdoor air per unit of time (air changes per hour, or "ach") or the rate at which a volume of outdoor air enters per unit of time (cubic feet per minute, or "cfm").
Volatile Organic Compounds (VOCs) - Chemicals that contain carbon molecules and are volatile enough to evaporate from material surfaces into indoor air at normal room temperatures (referred to as off-gassing).
Zero-VOC - A term used to indicate paint containing no volatile organic compounds- a healthier alternative to conventional paints
Insulation
Air sealing - A weatherization strategy that reduces air leaks in a home, measured by blower door test readings. "Major air sealing" includes sealing large openings between the heated/unheated spaces. "Minor air sealing" includes sealing small air gaps with caulk, weather stripping, and gaskets.
Baffles - Device to maintain a ventilation space between the insulation and roof deck, assuring air flow from the eave/soffit vents to ridge vent or other roof vents provided in attics and cathedral ceilings (Owens Corning product is Raft-R-Mate Batt Insulation that is pre-cut to a certain width.
Blow in loose - fill Material (usually mineral wool or cellulose) used for pouring or blowing into the space to be insulated. Air is usually the blowing agent. It air seals simultaneously as it insulates.
Building or Thermal Envelope - The entire perimeter of a building enclosed by its roof, walls and foundation. Properly designed the envelope can minimize temperature gain or loss and moisture infiltration. Five components of a building that ensure maximum retention and minimal loss of heat, minimal chemical fumes and other factors that contribute to a safe, secure living environment:
- Weather Barrier - a building’s outer skin that keeps it dry.
- Air Barrier - limits air leakage or infiltration from outside.
- Thermal Barrier - prevents movement of heat in or out.
- Vapor Barrier - prevents movement of moisture in or out.