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Convection Heater
A convection heater (otherwise known as a convector heater) is a type of heater that uses convection currents to heat and circulate air. These currents circulate throughout the body of the appliance and across its heating element. This process, following the principle of thermal conduction, heats up the air, reducing its density relative to colder air and causing it to rise. As heated air molecules rise, they displace cooler air molecules down towards the heating appliance. The displaced cool air is heated as a result, decreases in density, rises, and repeats the cycle. History Ancient heating systems, including hearths, furnaces, and stoves, operated primarily through convection. Fixed central hearths, which were first excavated and retrieved in Greece, date back to 2500BC, while crude fireplaces were used as early as the 800sAD and in the 13th century, when castles in Europe were built with fireplaces with a crude form of chimney. Developments in convection heating techn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Heater
Electric heating is a process in which electrical energy is converted directly to heat energy at around 100% efficiency, using rather cheap devices. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an 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 300% efficiency for heating, or 3.0 Coefficient of performance, because it uses electric power only for transferring existing thermal energy from the surrounding area, mostly air. The heat pump uses an electric moto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of an electric charge, which can be either positive or negative, produces an electric field. The movement of electric charges is an electric current and produces a magnetic field. When a charge is placed in a location with a non-zero electric field, a force will act on it. The magnitude of this force is given by Coulomb's law. If the charge moves, the electric field would be doing work on the electric charge. Thus we can speak of electric potential at a certain point in space, which is equal to the work done by an external agent in carrying a ... [...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 at around 100% efficiency, using rather cheap devices. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an 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 300% efficiency for heating, or 3.0 Coefficient of performance, because it uses electric power only for transferring existing thermal energy from the surrounding area, mostly air. The heat pump uses an electric mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiator (heating)
Radiators and convectors are heat exchangers designed to transfer thermal energy from one medium to another for the purpose of space heating. Denison Olmsted of New Haven, Connecticut, appears to have been the earliest person to use the term 'radiator' to mean a heating appliance in an 1834 patent for a stove with a heat exchanger which then radiated heat. In the patent he wrote that his invention was ''a peculiar kind of apparatus, which I call a radiator''. The heating radiator was invented by Franz San Galli in 1855, a Kingdom of Prussia-born Russian businessman living in St. Petersburg. In the late 1800s, companies, such as the American Radiator Company, promoted cast iron radiators over previous fabricated steel designs in order to lower costs and expand the market. Radiation vs. convection In practice, the term '' radiator'' refers to any of a number of devices in which a fluid circulates through exposed pipes (often with fins or other means of increasing surface area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Capacity
Heat capacity or thermal capacity is a physical property of matter, defined as the amount of heat to be supplied to an object to produce a unit change in its temperature. The SI unit of heat capacity is joule per kelvin (J/K). Heat capacity is an extensive property. The corresponding intensive property is the specific heat capacity, found by dividing the heat capacity of an object by its mass. Dividing the heat capacity by the amount of substance in moles yields its molar heat capacity. The volumetric heat capacity measures the heat capacity per volume. In architecture and civil engineering, the heat capacity of a building is often referred to as its thermal mass. Definition Basic definition The heat capacity of an object, denoted by C, is the limit : C = \lim_\frac, where \Delta Q is the amount of heat that must be added to the object (of mass ''M'') in order to raise its temperature by \Delta T. The value of this parameter usually varies considerably depending on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Heater
An oil heater, also known as an oil-filled heater, oil-filled radiator, or column heater, is a common form of convection heater used in domestic heating. Although filled with oil, it is electrically heated and does not involve burning any oil fuel; the oil is used as a heat reservoir (buffer), not as a fuel. Function Oil heaters consist of metal columns with cavities inside, where heat transfer oil flows freely around the heater. A heating element at the base of the heater heats up the oil, which flows around the cavities of the heater by convection. The oil has a relatively high specific heat capacity and high boiling point. The high specific heat capacity allows the oil to effectively transfer thermal energy from the heating element, while the oil's high boiling point allows it to remain in the liquid phase for the purpose of heating, so that the heater does not have to be a high pressure vessel. The heating element heats the oil, which transfers heat to the metal wall t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tangential Fan
A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an ''impeller'', ''rotor'', or ''runner''. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines. Mechanically, a fan can be any revolving wikt:vane#English, vane, or vanes used for producing air current, currents of air. Fans produce air flows with high volume and low pressure (although higher than ambient pressure), as opposed to gas compressor, compressors which produce high pressures at a comparatively low volume. A fan blade will often rotate when exposed to an air-fluid stream, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Heating
A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning (short: HVAC) systems, which can both cool and warm interior spaces. A central heating system has a furnace that converts fuel or electricity to heat. The heat is circulated through the building either by fans forcing heated air through ducts, circulation of low-pressure steam to radiators in each heated room, or pumps that circulate hot water through room radiators. Primary energy sources may be fuels like coal or wood, oil, kerosene, natural gas, or electricity. Compared with systems such as fireplaces and wood stoves, a central heating plant offers improved uniformity of temperature control over a building, usually including automatic control of the furnace. Large homes or buildings may be divided into individually controllable zones with their own temperature controls. Automatic fuel (and sometimes ash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Radiator
Electric heating is a process in which electrical energy is converted directly to heat energy at around 100% efficiency, using rather cheap devices. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an 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 300% efficiency for heating, or 3.0 Coefficient of performance, because it uses electric power only for transferring existing thermal energy from the surrounding area, mostly air. The heat pump uses an electric moto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resistance Wire
Resistance wire is wire intended for making electrical resistors (which are used to control the amount of current in a circuit). It is better if the alloy used has a high resistivity, since a shorter wire can then be used. In many situations, the stability of the resistor is of primary importance, and thus the alloy's temperature coefficient of resistivity and corrosion resistance play a large part in material selection. When resistance wire is used for heating elements (in electric heaters, toasters, and the like), high resistivity and oxidation resistance is important. Sometimes resistance wire is insulated by ceramic powder and sheathed in a tube of another alloy. Such heating elements are used in electric ovens and water heaters, and in specialized forms for cooktops. __TOC__ Types Nichrome, a non-magnetic 80/20 alloy of nickel and chromium, is the most common resistance wire for heating purposes because it has a high resistivity and resistance to oxidation at high temper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propane
Propane () is a three-carbon alkane with the molecular formula . It is a gas at standard temperature and pressure, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used as a fuel in domestic and industrial applications and in low-emissions public transportation. Discovered in 1857 by the French chemist Marcellin Berthelot, it became commercially available in the US by 1911. Propane is one of a group of liquefied petroleum gases (LP gases). The others include butane, propylene, butadiene, butylene, isobutylene, and mixtures thereof. Propane has lower volumetric energy density, but higher gravimetric energy density and burns more cleanly than gasoline and coal. 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 (2 phases). Propane powers buses, forklifts, taxis, outboard boat motors, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiant Heat
Thermal radiation is electromagnetic radiation generated by the thermal motion of particles in matter. Thermal radiation is generated when heat from the movement of charges in the material (electrons and protons in common forms of matter) is converted to electromagnetic radiation. All matter with a temperature greater than absolute zero emits thermal radiation. At room temperature, most of the emission is in the infrared (IR) spectrum. Particle motion results in charge-acceleration or dipole oscillation which produces electromagnetic radiation. Infrared radiation emitted by animals (detectable with an infrared camera) and cosmic microwave background radiation are examples of thermal radiation. If a radiation object meets the physical characteristics of a black body in thermodynamic equilibrium, the radiation is called blackbody radiation. Planck's law describes the spectrum of blackbody radiation, which depends solely on the object's temperature. Wien's displacement la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
