Misplaced Pages

#860139

27-686: At the factory on the Boulevard Devaux in Poissy, Grégoire started off by manufacturing engines in 1903, but in 1904, the company started to manufacture automobiles. The design was easily recognisable by its pear-shaped radiator . The company made cars with single-, two- and four-cylinder engines . In 1911, a six-cylinder and a four-cylinder sleeve-valve engine were also produced. The Grégoire company never sold many automobiles. In 1913, only 500 cars were made. After World War I , Grégoire introduced its first car with an overhead-valve engine. Although

54-465: A central boiler and circulated by pumps through radiators within the building, where this heat is transferred to the surroundings. In some countries, portable radiators are common to heat a single room, as a safer alternative to space heater and fan heater . Radiators are used in dry cooling towers and closed-loop cooling towers for cooling buildings using liquid-cooled chillers for heating, ventilation, and air conditioning (HVAC) while keeping

81-434: A device like a fan to generate air flow and spread heat at a fast pace. Sometimes called "fan heaters," these are often cheap but lack in efficiency and versatility. Radiant space heaters transfer heat to directly to bodies in front of them using thermal radiation. Thermal radiation is a process by which objects at a high temperature emit heat in the form of electromagnetic waves . These heaters are often designed such that

108-406: A lower heat capacity and density than liquid coolants, a fairly large volume flow rate (relative to the coolant's) must be blown through the radiator core to capture the heat from the coolant. Radiators often have one or more fans that blow air through the radiator. To save fan power consumption in vehicles, radiators are often behind the grille at the front end of a vehicle. Ram air can give

135-467: A lower risk of fire (and burns) than other oil-filled heaters. No one type of heater is safer than any other type. The risk of fire and burns can vary, depending on model and manufacturer. In the United States, Underwriters Laboratories ' UL 1278 (for portable electric space heaters) and UL 1042 standards (for portable and fixed baseboard electric heaters) certify heater safety. Although

162-439: A portion or all of the necessary cooling air flow when the coolant temperature remains below the system's designed maximum temperature, and the fan remains disengaged. As electronic devices become smaller, the problem of dispersing waste heat becomes more difficult. Tiny radiators known as heat sinks are used to convey heat from the electronic components into a cooling air stream. Heatsinks do not use water, rather they conduct

189-405: A primitive radiator in 1841 and received a number of U.S. patents for hot water and steam heating. Heat transfer from a radiator occurs by two mechanisms: thermal radiation and convection into flowing air or liquid. Conduction is not normally a major source of heat transfer in radiators. A radiator may even transfer heat by phase change , for example, drying a pair of socks. In practice,

216-410: A user to discern a difference in temperature. By the mid-2010s, some higher-end models included more precise controls. The power source used in a radiant heater depends on the resources that are available. Most space heaters are either powered by electricity or combustion. Electric space heaters convert electricity into heat through the process of Joule heating . The main component of these heaters

243-480: Is a heat exchanger used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars , buildings , and electronics . A radiator is always a source of heat to its environment, although this may be for either the purpose of heating an environment, or for cooling the fluid or coolant supplied to it, as for automotive engine cooling and HVAC dry cooling towers. Despite

270-400: Is called the heating element . Heating elements come in many different geometries and styles and can be used in either convective or radiant space heaters. Combustion space heaters convert chemical energy into heat through combustion of a fuel. These heaters often do not require electricity to function and can therefore be used off-the-grid. Fire, burns, and carbon monoxide poisoning are

297-625: The General Services Administration had Specification W-H-193 for electric space heaters, it was replaced in 1995 by the UL standards. Additional information on portable-heater safety may be found at the Department of Energy's Energy Efficiency website. New York City law regulates the safety of space heaters. Space heaters for sale in the city must have a thermostat to control temperature, an automatic shut-off feature if

SECTION 10

#1732776341861

324-446: The chiller coolant isolated from the surroundings. Radiators are used for cooling internal combustion engines , mainly in automobiles but also in piston-engined aircraft, railway locomotives , motorcycles , stationary generating plants and other places where heat engines are used ( watercrafts , having an unlimited supply of a relatively cool water outside, usually use the liquid-liquid heat exchangers instead). To cool down

351-486: The coolant; today, however, all but the smallest engines use pumps . Up to the 1980s, radiator cores were often made of copper (for fins) and brass (for tubes, headers, and side-plates, while tanks could also be made of brass or of plastic , often a polyamide ). Starting in the 1970s, use of aluminium increased, eventually taking over the vast majority of vehicular radiator applications. The main inducements for aluminium are reduced weight and cost. Since air has

378-571: The engine was only 2.3 litre, the car could reach up to 62 mph (100 km/h). The manufacture of this model was expensive, and it had disappointing financial results. In 1923, Grégoire only produced engines for the Bignan company. Grégoire closed its factory down in 1924. At the 1902 Salon aéronautique, Grégoire offered engines for airships. From these, the company evolved towards aircraft engines- "Moteurs d'Aviation Grégoire-Gyp"- made at Suresnes. The initials of Pierre J. Grégoire (G.Y.P.) provided

405-405: The frequency of the emitted waves are in the infrared part of the electromagnetic spectrum . The materials used in radiant heaters can vary. Halogen heaters have tungsten filaments in sealed quartz envelopes, mounted in front of a metal reflector in a plastic case. They operate at a higher temperature than nichrome-wire heaters but not as high as incandescent light bulbs, radiating primarily in

432-417: The heat engine, a coolant is passed through the engine block , where it absorbs heat from the engine. The hot coolant is then fed into the inlet tank of the radiator (located either on the top of the radiator, or along one side), from which it is distributed across the radiator core through tubes to another tank on the opposite end of the radiator. As the coolant passes through the radiator tubes on its way to

459-512: The heat from the source. High-performance heat sinks have copper to conduct better. Heat is transferred to the air by conduction and convection; a relatively small proportion of heat is transferred by radiation owing to the low temperature of semiconductor devices compared to their surroundings. Radiators are also used in liquid cooling loops for rejecting heat. Radiators are found as components of some spacecraft. These radiators work by radiating heat energy away as light (generally infrared given

486-408: The infrared spectrum. They convert up to 86 percent of their input power to radiant energy , losing the remainder to conductive and convective heat. Oil heaters transfer heat by convection and radiation . They can silently heat larger rooms, but take longer to heat up. Like infrared models, they lack a fan, but circulate heat according to a room's air patterns, which is why it may take longer for

513-530: The main risks of space heaters. About 25,000 fires are caused by space heaters in the United States each year, resulting in about 300 deaths. Roughly 6,000 hospital emergency department visits annually in the US are caused by space heaters, mainly from burns. Improper use can increase the risk of fire and burns. Safe operation includes: The risk of fire (and burns) is sometimes less with oil-filled heaters than those with fans, but some fan-assisted heaters have

540-430: The name for these engines. They were built in various configurations, and in four variants by power and weight, from 25/30 cv, 60 kg, to 120/140 cv, 240 kg. This French corporation or company article is a stub . You can help Misplaced Pages by expanding it . This article about an automotive industry corporation or company is a stub . You can help Misplaced Pages by expanding it . Radiator A radiator

567-477: The name, most radiators transfer the bulk of their heat via convection instead of thermal radiation . The Roman hypocaust is an early example of a type of radiator for building space heating. Franz San Galli , a Prussian-born Russian businessman living in St. Petersburg , is credited with inventing the heating radiator around 1855, having received a radiator patent in 1857, but American Joseph Nason developed

SECTION 20

#1732776341861

594-402: The opposite tank, it transfers much of its heat to the tubes which, in turn, transfer the heat to the fins that are lodged between each row of tubes. The fins then release the heat to the ambient air. Fins are used to greatly increase the contact surface of the tubes to the air, thus increasing the exchange efficiency. The cooled liquid is fed back to the engine, and the cycle repeats. Normally,

621-418: The radiator does not reduce the temperature of the coolant back to ambient air temperature, but it is still sufficiently cooled to keep the engine from overheating. This coolant is usually water-based, with the addition of glycols to prevent freezing and other additives to limit corrosion , erosion and cavitation . However, the coolant may also be an oil. The first engines used thermosiphons to circulate

648-689: The temperatures at which spacecraft try to operate) because in the vacuum of space neither convection nor conduction can work to transfer heat away. On the International Space Station , these can be seen clearly as large white panels attached to the main truss . They can be found on both crewed and uncrewed craft. Space heater A space heater is a device used to heat a single, small- to medium-sized area. This type of heater can be contrasted with central heating , which distributes heat to multiple areas. All space heaters transfer heat to their environment via some combination of

675-407: The term "radiator" refers to any of a number of devices in which a liquid circulates through exposed pipes (often with fins or other means of increasing surface area). The term " convector " refers to a class of devices in which the source of heat is not directly exposed. To increase the surface area available for heat exchange with the surroundings, a radiator will have multiple fins, in contact with

702-499: The three fundamental modes of heat transfer: convection , radiation , and conduction . Typically heaters are designed with either convection or radiation as the sole dominant mode. Convective space heaters utilize convection to transfer heat from the power source to a space. These heaters typically either rely on natural or forced convection. Natural convection is a phenomenon where temperature variations in an environment generate fluid flow. Forced convection heaters utilize

729-463: The tube carrying liquid pumped through the radiator. Air (or other exterior fluid) in contact with the fins carries off heat. If air flow is obstructed by dirt or damage to the fins, that portion of the radiator is ineffective at heat transfer. Radiators are commonly used to heat buildings on the European continent. In a radiative central heating system , hot water or sometimes steam is generated in

#860139