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Annual Fuel Use Efficiency
The annual fuel utilization efficiency (AFUE; pronounced 'A'-'Few' or 'A'-'F'-'U'-'E') is a thermal efficiency measure of space-heating furnaces and boilers. The AFUE differs from the true 'thermal efficiency' in that it is not a steady-state, peak measure of conversion efficiency, but instead attempts to represent the actual, season-long, average efficiency of that piece of equipment, including the operating transients. It is a dimensionless ratio of useful energy output to energy input, expressed as a percentage. For example, a 90% AFUE for a gas furnace means it outputs 90 BTUs of useful heating for every 100 BTUs of natural gas input (where the rest may be wasted heat in the exhaust). A higher AFUE means higher efficiency. The method for determining the AFUE for residential furnaces and boilers is the subject of ASHRAE Standard 103. A furnace with a thermal efficiency (ηth) of 78% may yield an AFUE of only 64% or so, for example, under the standard's test conditions. When es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Efficiency
In thermodynamics, the thermal efficiency (\eta_) is a dimensionless performance measure of a device that uses thermal energy, such as an internal combustion engine, steam turbine, steam engine, boiler, furnace, refrigerator, ACs etc. For a heat engine, thermal efficiency is the ratio of the net work output to the heat input; in the case of a heat pump, thermal efficiency (known as the '' coefficient of performance'' or COP) is the ratio of net heat output (for heating), or the net heat removed (for cooling) to the energy input (external work). The efficiency of a heat engine is fractional as the output is always less than the input while the COP of a heat pump is more than 1. These values are further restricted by the Carnot theorem. Overview In general, energy conversion efficiency is the ratio between the useful output of a device and the input, in energy terms. For thermal efficiency, the input, Q_, to the device is heat, or the heat-content of a fuel that is c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geothermal Heat Pump
A ground source heat pump (also geothermal heat pump) is a heating/cooling system for buildings that use a type of heat pump to transfer heat to or from the ground, taking advantage of the relative constancy of temperatures of the earth through the seasons. Ground-source heat pumps (GSHPs)or geothermal heat pumps (GHP), as they are commonly termed in North Americaare among the most energy-efficient technologies for providing HVAC and water heating, using less energy than can be achieved by use of resistive electric heaters. Efficiency is given as a coefficient of performance (CoP) which is typically in the range 3-6, meaning that the devices provide 3-6 units of heat for each unit of electricity used. Setup costs are higher than for other heating systems, due to the requirement of installing ground loops over large areas or of drilling bore holes, hence ground source is often installed when new blocks of flats are built. Air-source heat pumps have lower set-up costs but have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seasonal Energy Efficiency Ratio
In the United States, the efficiency of air conditioners is often rated by the seasonal energy efficiency ratio (SEER) which is defined by the Air Conditioning, Heating, and Refrigeration Institute, a trade association, in its 2008 standard AHRI 210/240, ''Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment''. A similar standard is the European seasonal energy efficiency ratio (ESEER). The SEER rating of a unit is the cooling output during a typical cooling-season divided by the total electric energy input during the same period. The higher the unit's SEER rating the more energy efficient it is. In the U.S., the SEER is the ratio of cooling in British thermal units (BTUs) to the energy consumed in watt-hours. Example For example, consider a 5000 BTU/h (1465-watt cooling capacity) air-conditioning unit, with a SEER of 10 BTU/(W·h), operating for a total of 1000 hours during an annual cooling season (e.g., 8 hours per day for 125 days). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firewood
Firewood is any wooden material that is gathered and used for fuel. Generally, firewood is not heavily processed, and is in some sort of firelog, recognizable log or branch form, compared to other forms of wood fuel like pellet fuel, pellets. Firewood can be seasoned and heat treated (dry) or unseasoned (fresh/wet). It is generally classified as either hardwood or softwood. Firewood is a renewable resource. However, demand for this fuel can outpace its ability to regenerate on a local or regional level. Good forestry practices and improvements in devices that use firewood can improve local wood supplies. Smoke from fire created by burning wood causes respiratory and other diseases. Moreover, transporting firewood long distances can potentially spread plant pests/diseases and invasive species. History For most of human history, firewood was the main fuel, until the use of coal spread during the Industrial Revolution. As such, access to firewood was a valued resource, with E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propane
Propane () is a three-carbon chain alkane with the molecular formula . It is a gas at standard temperature and pressure, but becomes liquid when compressed for transportation and storage. A by-product of natural gas processing and petroleum refining, it is often a constituent of liquefied petroleum gas (LPG), which is commonly used as a fuel in domestic and industrial applications and in low-emissions public transportation; other constituents of LPG may include propene, propylene, butane, butene, butylene, butadiene, and isobutylene. Discovered in 1857 by the French chemist Marcellin Berthelot, it became commercially available in the US by 1911. Propane has lower volumetric energy density than gasoline or coal, but has higher gravimetric energy density than them and burns more cleanly. Propane gas has become a popular choice for barbecues and portable stoves because its low −42 °C boiling point makes it vaporise inside pressurised liquid containers (it exists in two pha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Gas
Natural gas (also fossil gas, methane gas, and gas) is a naturally occurring compound of gaseous hydrocarbons, primarily methane (95%), small amounts of higher alkanes, and traces of carbon dioxide and nitrogen, hydrogen sulfide and helium. Methane is a colorless and odorless gas, and, after carbon dioxide, is the second-greatest greenhouse gas that contributes to global climate change. Because natural gas is odorless, a commercial odorizer, such as Methanethiol (mercaptan brand), that smells of hydrogen sulfide (rotten eggs) is added to the gas for the ready detection of gas leaks. Natural gas is a fossil fuel that is formed when layers of organic matter (primarily marine microorganisms) are thermally decomposed under oxygen-free conditions, subjected to intense heat and pressure underground over millions of years. The energy that the decayed organisms originally obtained from the sun via photosynthesis is stored as chemical energy within the molecules of methane and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HSPF
Heating seasonal performance factor (HSPF) is a term used in the heating and cooling industry. HSPF is specifically used to measure the efficiency of air source heat pumps. HSPF is defined as the ratio of heat output (measured in BTUs) over the heating season to electricity used (measured in watt-hours). It therefore has units of BTU/watt-hr. The higher the HSPF rating of a unit, the more energy efficient it is. An electrical resistance heater, which is not considered efficient, has an HSPF of 3.41. Depending on the system, an HSPF ≥ 9 can be considered high efficiency and worthy of a US energy tax credit. For instance, a system which delivers an HSPF of 7.7 will transfer 2.25 times as much heat as electricity consumed over a season.7.7 times 0.293 is 2.25. Alternatively, 7.7 divided by 3.41 is 2.25 In Europe the term '' seasonal performance factor'' ("SPF") is used to mean the same as the average COP over the heating season. A system which transfers 2.25 times as much heat as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Source Heat Pump
An air source heat pump (ASHP) is a heat pump that can absorb heat from air outside a building and release it inside; it uses the same vapor-compression refrigeration process and much the same equipment as an air conditioner, but in the opposite direction. ASHPs are the most common type of heat pump and, usually being smaller, tend to be used to heat individual houses or flats rather than blocks, districts or industrial processes. ''Air-to-air'' heat pumps provide hot or cold air directly to rooms, but do not usually provide hot water. ''Air-to-water'' heat pumps use radiators or underfloor heating to heat a whole house and are often also used to provide domestic hot water. An ASHP can typically gain 4 kWh thermal energy from 1 kWh electric energy. They are optimized for flow temperatures between , suitable for buildings with heat emitters sized for low flow temperatures. With losses in efficiency, an ASHP can even provide full central heating with a flow tempera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Heating
Electric heating is a process in which electrical energy is converted directly to heat energy. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an electricity, electrical device that converts an electric current into heat. The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy. Most modern electric heating devices use nichrome wire as the active element; the heating element, depicted on the right, uses nichrome wire supported by ceramic insulators. Alternatively, a heat pump can achieve around 150% – 600% efficiency for heating, or COP 1.5 - 6.0 Coefficient of performance, because it uses electric power only for transferring existing thermal energy. The heat pump uses an electric motor to drive a reversed refrigeration cycle, that draws heat energy f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furnace (house Heating)
A furnace (American English), referred to as a heater or boiler in British English, is an appliance used to generate heat for all or part of a building. Furnaces are mostly used as a major component of a central heating system. Furnaces are permanently installed to provide heat to an interior space through intermediary fluid movement, which may be air, steam, or hot water. Heating appliances that use steam or hot water as the fluid are normally referred to as a residential steam boilers or residential hot water boilers. The most common fuel source for modern furnaces in North America and much of Europe is natural gas; other common fuel sources include LPG (liquefied petroleum gas), fuel oil, wood and in rare cases coal. In some areas electrical resistance heating is used, especially where the cost of electricity is low or the primary purpose is for air conditioning. Modern high-efficiency furnaces can be up to 98% efficient and operate without a chimney, with a typical gas fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heating Oil
Heating oil is any petroleum product or other oil used for heating; it is a fuel oil. Most commonly, it refers to low viscosity grades of fuel oil used for furnaces or boilers for home heating and in other buildings. Home heating oil is often abbreviated as HHO. Most heating oil products are chemically very similar to diesel fuel used as motor fuel; motor fuel is typically subject to higher fuel taxes. Many countries add fuel dyes to heating oil, allowing law enforcement to check if a driver is evading fuel taxes. Since 2002, Solvent Yellow 124 has been added as a "Euromarker" in the European Union; untaxed diesel is known as "red diesel" in the United Kingdom. Heating oil is commonly delivered by tank truck to residential, commercial, and municipal buildings and stored in above-ground storage tanks ("ASTs") located in the basements, garages, or outside adjacent to the building. It is sometimes stored in underground storage tanks (or "USTs") but less often than ASTs. AS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
