Window Energy Glossary
Window Energy Glossary
Air Leakage Rating: A measure of the ratebof infiltration around a window or skylight in the presence of a strong wind. It is expressed in units of cubic feet per minute per square foot (cfm/ft2) of window area or cubic feet per minute per foot (cfm/ft) of window perimeter length. The lower a window's air leakage rating, the better its airtightness.
Conduction: The flow of heat through a solid material, such as glass or wood, and from one material to another in an assembly, such as a window, through direct contact.
Convection: The flow of heat through a circulating gas or liquid, such as the air in a room or the air or gas between windowpanes.
Fenestration: A window or skylight and its associated interior or exterior elements, such as shades or blinds. The placement of window openings in a building wall is one of the important elements in determining the exterior appearance of a building.
Gas Fill: A gas other than air placed between window or skylight glazing panes to reduce the U-factor by suppressing conduction and convection.
Glazing: The glass or plastic panes in a window or skylight.
Infiltration: The inadvertent flow of air into a building through breaks in the exterior surfaces of the building. It can occur through joints and cracks around window and skylight frames, sash, and glazings.
Low-Emittance (Low-E) Coating: Microscopically thin, virtually invisible,metal or metallic oxide layers deposited ona window or skylight glazing surface primarilyto reduce the U-factor by suppressingradiative heat flow through the windowor skylight.
Radiation: The transfer of heat in the form of electromagnetic waves from one separate surface to another. Energy from the sun reaches the earth by radiation, and a person's body can lose heat to a cold window or skylight surface in a similar way.
R-Value: A measure of the resistance of a material or assembly to heat flow. It is the inverse of the U-factor (R = 1/U) and is expressed in units of hr-ft2-°F/Btu. A high window R-value, has a greater resistance to heat flow and a higher insulating value.
Shading Coefficient (SC): A measure of the ability of a window or skylight to transmit solar heat, relative to that ability for 1/8-inch clear, double-strength, single glass. It is equal to the Solar Heat Gain Coefficient multiplied by 1.15 and is expressed as a number without units between 0 and 1. A window with a lower Shading Coefficient transmits less solar heat, and provides better shading.
Solar Heat Gain Coefficient (SHGC): The fraction of solar radiation admittedthrough a window or skylight, both directly transmitted, and absorbed andsubsequently released inward. The SolarHeat Gain Coefficient has replaced theShading Coefficient as the standard indicatorof a window's shading ability. It isexpressed as a number without unitsbetween 0 and 1. A window with a lowerSolar Heat Gain Coefficient transmits lesssolar heat, and provides better shading.
Spectrally Selective Glazing: A specially engineered low-E coated or tinted glazing that blocks out much of the sun's heat while transmitting substantial daylight.
U-Factor (U-Value): A measure of the rate of heat flow through a material or assembly. It is expressed in units of Btu/hr-ft2-°F or W/m2-°C. Window manufacturers and engineers commonly use the U-factor to describe the rate of non-solar heat loss or gain through a window or skylight. Lower window U-factors have greater resistance to heat flow and better insulating value.
Visible Transmittance: The percentage or fraction of visible light transmitted by a window or skylight.
Questions and Answers
Article Tags:
energy
Spring is finally here, which means its time for home improvements. In this article we will discuss making your home energy efficient and home improvement tips to help save energy and money.
People have started taking energy shots more than energy drinks. The secret behind the success of energy shots is its instant effect on the body. Energy drinks have almost been replaced by its newer version known as shots.
Most of us don't seem to mind about how we make use of energy at home. You simply get shocked when you receive your monthly energy bill; you didn't even notice how much it has increased for the couple of months.
Shared by Sustainable Energy Why Are Energy Monitoring Systems Important? There are a lot of energy monitoring systems available on the market. What do these systems do? Generally they monitor energy usage in a facility. This is a very crucial system that most companies do not have in place. The only reference they have is their power bill that comes once a month. They look at their regular monthly costs rising, but they do not know where they can help save energy. Think about ...
An energy audit looks at several specific features of your home. It's designed to help consumers understand their home's energy use. With a home energy audit, consumers will be able to be energy efficient and save on their energy costs.
The company Energy Sprint has decided to promote the Energy Sprint, through Facebook. Soon there will come a Facebook application which will explore Energy Sprint. Facebook is an extraordinary method to promote a brand. Thanks to viral marketing in a few days all will know Energy sprint card Who will become fans of Energy Sprint Energy can earn through Energy Sprint. Energy sprint Facebook application will become a Fan of Energy Sprint
Everyone loves a good party, but clearing up afterwards is not so fun. Preparing for the party in advance can make all the difference.
Removing black mold can be a daunting process, especially knowing that it is a highly toxic and potentially life threatening mold. That is why its important to arm yourself with the right knowledge before you undertake a mold removal job yourself, this article is the perfect place to start.
From 06/04/12, Commercial Solar planning permission will no longer be required on non-domestic buildings for installations of Solar PV (upto 50kWp electricity) and Solar Thermal (upto 45 kilowatts thermal).
Whenever someone talks about energy savings, then the first things that come to mind are televisions, refrigerators, dishwashers and computers etc.
Home maintenance and DIY are satisfying tasks that can save you thousands of pounds. But when it comes to improving you home, you want to be sure that you are using the very best materials. It's often a false economy to try and save money by using sub-standard goods, but they will not live up to the time and effort you have put into installing them.
arren and molten, the new planet earth first orbited the sun five to ten billion years ago. Even after the crust solidified and the depressions filled with water, this barrenness persisted. Chemical elements and simple compounds were randomly scattered on the surface. Organization of the elements into complex organic compounds was unknown.
At most sites, what is called run of river is the best mode of operation. This means that power is produced at a constant rate according to the amount of water available. Usually the power is generated as electricity and stored in batteries and can be tied to an existing PV or other system. The power can take other forms: shaft power for a saw, pump, grinder, etc. Both head and flow are necessary to produce power.
At most sites, what is called run of river is the best mode of operation. This means that power is produced at a constant rate according to the amount of water available. Usually the power is generated as electricity and stored in batteries and can be tied to an existing PV or other system. The power can take other forms: shaft power for a saw, pump, grinder, etc. Both head and flow are necessary to produce power.
In the 1880s, Henry Ford developed a prototype automobile (the quadracycle) that could be operated with ethanol as fuel. Historians say that Ford always believed that the Model T and his future cars would use alcohol as fuel because it was a renewable energy source and would boost the agricultural economy.
Anybody can make biodiesel. It's easy, you can make it in your kitchen -- and it's BETTER than the petro-diesel fuel the big oil companies sell you. Your diesel motor will run better and last longer on your home-made fuel, and it's much cleaner -- better for the environment and better for health.
Discuss this Article
