Misplaced Pages

#165834

75-528: Armour protection is improved compared with the BTR-80, giving protection from 14.5 mm projectiles over the frontal arc. It is armed with a 2A42 30 mm auto cannon , a coaxial 7.62 mm PKT machine gun, an 9M113 Konkurs ATGM, as well as an AGS-17D 30 mm automatic grenade launcher. Limited numbers have been produced and are in service with the National Guard of Russia . The development of

150-420: A crankcase , crankshaft , piston rod , piston , piston ring , cylinder head and valves. This compressor uses two interleaving scrolls to compress the refrigerant. it consists of one fixed and one orbiting scrolls. This type of compressor is more efficient because it has 70 percent less moving parts than a reciprocating compressor. This compressor use two very closely meshing spiral rotors to compress

225-501: A "wired thermostat," is a device that controls an air conditioner by switching heating or cooling on or off. It uses different sensors to measure temperatures and actuate control operations. Mechanical thermostats commonly use bimetallic strips , converting a temperature change into mechanical displacement, to actuate control of the air conditioner. Electronic thermostats, instead, use a thermistor or other semiconductor sensor, processing temperature change as electronic signals to control

300-534: A 1939 architecture graduate from the University of Texas at Austin , developed the first experimental "suburb" with inbuilt air conditioning in each house. 22 homes were developed on a flat, treeless track in northwest Austin, Texas , and the community was christened the 'Austin Air-Conditioned Village.' The residents were subjected to a year-long study of the effects of air conditioning led by

375-446: A 1P-13 commander's optical sight . Optionally, a BPK-M thermal imaging sight can be fitted in this compartment as the gunner's sight. The driver is located somewhat to the middle of the hull, just in front of the turret. The troop compartment is located behind the driver's position and the turret. The engine compartment is at the rear of the hull. Hatches are provided on the top of the turret and hull, and side doors are available on

450-570: A 24-hour period. The value is equal to 12,000 BTU IT per hour, or 3,517 watts . Residential central air systems are usually from 1 to 5 tons (3.5 to 18 kW) in capacity. 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 in its 2008 standard AHRI 210/240, Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment . A similar standard

525-494: A 30 mm AGS-17 automatic grenade launcher are the secondary armaments of the BTR-90. A guided missile system is available for engaging armoured targets. This consists of four 9M113 Konkurs missiles mounted on the turret. The launching unit is detachable, and can be used to launch missiles from the ground. All the weapons are mounted on the turret and are assisted by a fire control system . The fire control system allows

600-405: A cooling tower on its condenser side. An air source heat pump shares many components with an air conditioning system, but includes a reversing valve , which allows the unit to be used to heat as well as cool a space. Air conditioning equipment will reduce the absolute humidity of the air processed by the system if the surface of the evaporator coil is significantly cooler than the dew point of

675-422: A defrosting cycle to be performed. The icing problem becomes much more severe with lower outdoor temperatures, so heat pumps are sometimes installed in tandem with a more conventional form of heating, such as an electrical heater, a natural gas , heating oil , or wood-burning fireplace or central heating , which is used instead of or in addition to the heat pump during harsher winter temperatures. In this case,

750-778: A gap between the two walls to encourage air flow, were found in the ancient city of Hamoukar , in modern Syria . Ancient Egyptian buildings also used a wide variety of passive air-conditioning techniques. These became widespread from the Iberian Peninsula through North Africa, the Middle East, and Northern India. Passive techniques remained widespread until the 20th century when they fell out of fashion and were replaced by powered air conditioning. Using information from engineering studies of traditional buildings, passive techniques are being revived and modified for 21st-century architectural designs. Air conditioners allow

825-406: A load of 7,000 kg. An air conditioning system can be added optionally. The commander has the ability to carry out all-round surveillance and can take full control of the weapons from the gunner. An onboard information control system (OICS) enables automatic control over the transmission, engine and other important parts of the BTR-90, and it is the first armoured personnel carrier to have such

SECTION 10

#1732773223166

900-420: A maximum speed of 100 km/h, and has cross-country driving ability comparable to that of tracked vehicles , with an average speed of 50 km/h. The vehicle is fully amphibious and can negotiate water obstacles without any preparation. Two water jet propellers power the vehicle in water. In water it can achieve a maximum speed of 9 km/h. It can enter and be deployed from amphibious assault ships from

975-456: A patent in 1851, but following the death of his main backer, he was not able to realize his invention. In 1851, James Harrison created the first mechanical ice-making machine in Geelong, Australia , and was granted a patent for an ether vapor-compression refrigeration system in 1855 that produced three tons of ice per day. In 1860, Harrison established a second ice company. He later entered

1050-425: A quantity of gas from discharge to the suction side. The compressor will keep operating at the same speed, but due to the bypass, the refrigerant mass flow circulating with the system is reduced, and thus the cooling capacity. This naturally causes the compressor to run uselessly during the periods when the bypass is operating. The turn down capacity varies between 0 and 100%. Several compressors can be installed in

1125-405: A remote control to the air conditioner. The output of the infrared LED (like that of any infrared remote) is invisible to the human eye because its wavelength is beyond the range of visible light (940 nm). This system is commonly used on mini-split air conditioners because it is simple and portable. Some window and ducted central air conditioners uses it as well. A wired controller, also called

1200-460: A single or a few rooms of a building, without ducts and in a decentralized manner. Multi-zone or multi-split systems are a common application of ductless systems and allow up to eight rooms (zones or locations) to be conditioned independently from each other, each with its indoor unit and simultaneously from a single outdoor unit. The first mini-split system was sold in 1961 by Toshiba in Japan, and

1275-438: A split central system, and deliver air, possibly through ducts, to the spaces to be cooled. Depending on their construction they may be outdoors or indoors, on roofs ( rooftop units ), draw the air to be conditioned from inside or outside a building and be water or air-cooled. Often, outdoor units are air-cooled while indoor units are liquid-cooled using a cooling tower. medium (large capacity) This compressor consists of

1350-423: A system. A centralized tire pressure control system is available, and allows the vehicle to move even if four of its wheels are destroyed. The armour of the BTR-90 comprises welded steel armour plates . The armour can withstand hits from 14.5 mm rounds over the frontal arc. The side armour can provide protection against large caliber machine gun fire and shrapnel. Additional armoured plates can be installed on

1425-541: A thin film of ice formed on the surface of the thermometer's bulb and that the ice mass was about 6 mm ( 1 ⁄ 4  in) thick when they stopped the experiment upon reaching −14 °C (7 °F). Franklin concluded: "From this experiment, one may see the possibility of freezing a man to death on a warm summer's day." The 19th century included many developments in compression technology. In 1820, English scientist and inventor Michael Faraday discovered that compressing and liquefying ammonia could chill air when

1500-424: A window frame or on a wall opening. The unit usually has an internal partition separating its indoor and outdoor sides, which contain the unit's condenser and evaporator, respectively. PTAC systems may be adapted to provide heating in cold weather, either directly by using an electric strip, gas , or other heaters, or by reversing the refrigerant flow to heat the interior and draw heat from the exterior air, converting

1575-695: Is a heavy machine gun and anti-materiel rifle cartridge used by the Soviet Union , the former Warsaw Pact , modern Russia, and other countries. It was originally developed for the PTRS and PTRD anti-tank rifles , and was later used as the basis for the KPV heavy machine gun that formed the basis of the ZPU series anti-aircraft guns that is also the main armament of the BTR series of armoured personnel carriers from

SECTION 20

#1732773223166

1650-407: Is highly dependent on operating conditions, especially absolute temperature and relative temperature between sink and system, and is often graphed or averaged against expected conditions. Air conditioner equipment power in the U.S. is often described in terms of " tons of refrigeration ", with each approximately equal to the cooling power of one short ton (2,000 pounds (910 kg) of ice melting in

1725-503: Is rejected to the environment and an internal heat exchanger (the evaporator , or Fan Coil Unit, FCU) with the piped refrigerant being circulated between the two. The FCU is then connected to the spaces to be cooled by ventilation ducts . Floor standing air conditioners are similar to this type of air conditioner but sit within spaces that need cooling. Large central cooling plants may use intermediate coolant such as chilled water pumped into air handlers or fan coil units near or in

1800-469: Is the European seasonal energy efficiency ratio (ESEER). Efficiency is strongly affected by the humidity of the air to be cooled. Dehumidifying the air before attempting to cool it can reduce subsequent cooling costs by as much as 90 percent. Thus, reducing dehumidifying costs can materially affect overall air conditioning costs. This type of controller uses an infrared LED to relay commands from

1875-578: The BTR-60 to the BTR-80 and for heavy anti-materiel sniper rifles . The 14.5 × 114 mm has 42.53 ml (655 grains H 2 O) cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt-action rifles , semi-automatic rifles , and heavy machine guns alike, under extreme conditions. [REDACTED] 14.5×114 mm maximum cartridge dimensions. All dimensions in millimetres (mm). Americans define

1950-445: The BTR-80 , from which it is developed. A turbo charged, liquid cooled, multi-fuel diesel engine is used, which can develop 510 bhp. The vehicle has eight-wheel drive and has an automatic reversible hydro mechanical transmission, which is capable of providing different speeds to each side of the vehicle. It has duplicated electrical and compressed air engine start systems. The wheels use an independent torsion-bar suspension and

2025-518: The International Energy Agency (IEA) 1.6 billion air conditioning units were used globally in 2016. The United Nations called for the technology to be made more sustainable to mitigate climate change and for the use of alternatives, like passive cooling, evaporative cooling , selective shading, windcatchers , and better thermal insulation . Air conditioning dates back to prehistory. Double-walled living quarters, with

2100-534: The West ). Cooling in traditional air conditioner systems is accomplished using the vapor-compression cycle, which uses a refrigerant's forced circulation and phase change between gas and liquid to transfer heat. The vapor-compression cycle can occur within a unitary, or packaged piece of equipment; or within a chiller that is connected to terminal cooling equipment (such as a fan coil unit in an air handler) on its evaporator side and heat rejection equipment such as

2175-866: The humidity of internal air. Air conditioning can be achieved using a mechanical 'air conditioner' or by other methods, including passive cooling and ventilative cooling . Air conditioning is a member of a family of systems and techniques that provide heating, ventilation, and air conditioning (HVAC) . Heat pumps are similar in many ways to air conditioners, but use a reversing valve to allow them both to heat and to cool an enclosed space. Air conditioners, which typically use vapor-compression refrigeration , range in size from small units used in vehicles or single rooms to massive units that can cool large buildings. Air source heat pumps , which can be used for heating as well as cooling , are becoming increasingly common in cooler climates. Air conditioners can reduce mortality rates due to higher temperature. According to

2250-400: The refrigeration cycle and act as an air source heat pump , thus heating instead of cooling the indoor environment. They are also commonly referred to as "reverse cycle air conditioners". The heat pump is significantly more energy-efficient than electric resistance heating , because it moves energy from air or groundwater to the heated space and the heat from purchased electrical energy. When

2325-517: The BTR-90 chassis. The vehicle is designed to be highly mobile and maneuverable in all terrain, while providing a high level of protection for its crew and passengers. The BTR-90 is fitted with a gun turret identical to the one used on the BMP-2 . The BTR-90 has a pointed nose, somewhat similar to that of the LAV-25 . The hull is made of welded steel armour plate, and is slightly larger and higher than

BTR-90 - Misplaced Pages Continue

2400-608: The BTR-90 program could no longer be resurrected. On October 13, 2023, a video was posted on X (formerly Twitter) showing a BTR-90 operating in what is believed to be near Avdiivka , Donetsk Oblast area in Ukraine. On December 11, 2023, a video was posted on X showing the first visually confirmed Russian loss of a BTR-90, abandoned by the Russians in the Avdiivka sector. 14.5 mm caliber The 14.5×114mm (.57 calibre)

2475-840: The BTR-90 was carried out at the Arzamas Machine Building Plant (AMZ), a subsidiary of the Military Industrial Company . Development commenced in the early 1990s, with the first prototype completed and displayed to the public in 1994. The vehicle was intended to be used by mechanized units of the Russian army , as well as marine units of the Russian Navy , as a vehicle for providing fire support, transportation of personnel, surveillance, reconnaissance, and patrolling tasks. A wide range of vehicles suiting various requirements can be developed on

2550-523: The BTR-90 was produced with the low pressure 120 mm 2S9 Nona weapon, as with the BTR-80 Nona-SVK . Limited numbers have been produced and are in service with the National Guard of Russia . In October 2011, the Ministry of Defence refused to buy the BTR-90 and did not include them in the list of the state program of armament until 2020, and waived exports for the BTR-90. Subsequently,

2625-500: The Great Hall of Westminster Abbey with an apparatus of troughs and vats. Drebbel's contemporary Francis Bacon , like della Porta a believer in science communication , may not have been present at the demonstration, but in a book published later the same year, he described it as "experiment of artificial freezing" and said that "Nitre (or rather its spirit) is very cold, and hence nitre or salt when added to snow or ice intensifies

2700-498: The Russian army chose to assemble a large number of BTR-82A . The combat effectiveness has already increased significantly, and it is derived from the BTR-80. The development cost for BTR-82A is omitted and the production cost is cheaper, making the less advanced BTR-90 even less likely to change its fate. The 2015 Moscow Victory Parade exposed the next-generation VPK-7829 Bumerang wheeled armored vehicle, and officially announced that

2775-524: The Ukrainian "Horizon's Lord" sniper rifle fires a 12.7 × 114 HL round made by necking down a 14.5 × 114 mm cartridge case to accept a 12.7 mm / .50 BMG bullet. Air conditioning Air conditioning , often abbreviated as A/C (US) or air con (UK), is the process of removing heat from an enclosed space to achieve a more comfortable interior temperature (sometimes referred to as 'comfort cooling') and in some cases also strictly controlling

2850-410: The air conditioner into a heat pump . They may be installed in a wall opening with the help of a special sleeve on the wall and a custom grill that is flush with the wall and window air conditioners can also be installed in a window, but without a custom grill. Packaged air conditioners (also known as self-contained units) are central systems that integrate into a single housing all the components of

2925-400: The air conditioner. These controllers are usually used in hotel rooms because they are permanently installed into a wall and hard-wired directly into the air conditioner unit, eliminating the need for batteries. * where the typical capacity is in kilowatt as follows: Ductless systems (often mini-split, though there are now ducted mini-split) typically supply conditioned and heated air to

3000-441: The air in his textile mill. Cramer coined the term "air conditioning" in a patent claim which he filed that year, where he suggested that air conditioning was analogous to "water conditioning", then a well-known process for making textiles easier to process. He combined moisture with ventilation to "condition" and change the air in the factories; thus, controlling the humidity that is necessary in textile plants. Willis Carrier adopted

3075-440: The atmosphere even in liquid-cooled chillers through the use of cooling towers . Chillers may be air- or liquid-cooled. A portable system has an indoor unit on wheels connected to an outdoor unit via flexible pipes, similar to a permanently fixed installed unit (such as a ductless split air conditioner). Hose systems, which can be monoblock or air-to-air , are vented to the outside via air ducts. The monoblock type collects

BTR-90 - Misplaced Pages Continue

3150-617: The biggest increases in India and China . Between 1995 and 2004, the proportion of urban households in China with air conditioners increased from 8% to 70%. As of 2015, nearly 100 million homes, or about 87% of US households, had air conditioning systems. In 2019, it was estimated that 90% of new single-family homes constructed in the US included air conditioning (ranging from 99% in the South to 62% in

3225-626: The building's indoor environment to remain relatively constant, largely independent of changes in external weather conditions and internal heat loads. They also enable deep plan buildings to be created and have allowed people to live comfortably in hotter parts of the world. In 1558, Giambattista della Porta described a method of chilling ice to temperatures far below its freezing point by mixing it with potassium nitrate (then called "nitre") in his popular science book Natural Magic . In 1620, Cornelis Drebbel demonstrated "Turning Summer into Winter" for James I of England , chilling part of

3300-416: The building. Variable refrigerant flow indoor units can also be turned off individually in unused spaces. The lower start-up power of VRF's DC inverter compressors and their inherent DC power requirements also allow VRF solar-powered heat pumps to be run using DC-providing solar panels. Split-system central air conditioners consist of two heat exchangers , an outside unit (the condenser ) from which heat

3375-518: The cold of the latter, the nitre by adding to its cold, but the salt by supplying activity to the cold of the snow." In 1758, Benjamin Franklin and John Hadley , a chemistry professor at the University of Cambridge , conducted experiments applying the principle of evaporation as a means to cool an object rapidly. Franklin and Hadley confirmed that the evaporation of highly volatile liquids (such as alcohol and ether ) could be used to drive down

3450-400: The compression. There are several ways to modulate the cooling capacity in refrigeration or air conditioning and heating systems . The most common in air conditioning are: on-off cycling, hot gas bypass, use or not of liquid injection, manifold configurations of multiple compressors, mechanical modulation (also called digital), and inverter technology. Hot gas bypass involves injecting

3525-738: The debate over competing against the American advantage of ice-refrigerated beef sales to the United Kingdom. Electricity made the development of effective units possible. In 1901, American inventor Willis H. Carrier built what is considered the first modern electrical air conditioning unit. In 1902, he installed his first air-conditioning system, in the Sackett-Wilhelms Lithographing & Publishing Company in Brooklyn, New York . His invention controlled both

3600-575: The earlier has a conventional bullet jacket with a boat-tail. These have a long engraving portion that causes considerable barrel wear. The newer bullet types have a smaller engraving portion with a rounder boat-tail and were used from about 1957 onward. The cartridge has been manufactured in Bulgaria, China, Egypt, Hungary, Iraq, North Korea, Poland, Romania, Russia, and the former Czechoslovakia . There are new Chinese armour-piercing types: Anti-materiel rifles Machine guns Other In addition,

3675-565: The evaporator and the condenser into the same air path; the air first passes over the evaporator coil, where it is cooled and dehumidified before passing over the condenser coil, where it is warmed again before it is released back into the room. Free cooling can sometimes be selected when the external air is cooler than the internal air. Therefore, the compressor does not need to be used, resulting in high cooling efficiencies for these times. This may also be combined with seasonal thermal energy storage . Some air conditioning systems can reverse

3750-441: The first automobile manufacturer to offer an air conditioning unit in its cars in 1939. Innovations in the latter half of the 20th century allowed more ubiquitous air conditioner use. In 1945, Robert Sherman of Lynn, Massachusetts , invented a portable, in-window air conditioner that cooled, heated, humidified, dehumidified, and filtered the air. The first inverter air conditioners were released in 1980–1981. In 1954, Ned Cole,

3825-636: The first wall-mounted mini-split air conditioner was sold in 1968 in Japan by Mitsubishi Electric , where small home sizes motivated their development. The Mitsubishi model was the first air conditioner with a cross-flow fan . In 1969, the first mini-split air conditioner was sold in the US. Multi-zone ductless systems were invented by Daikin in 1973, and variable refrigerant flow systems (which can be thought of as larger multi-split systems) were also invented by Daikin in 1982. Both were first sold in Japan. Variable refrigerant flow systems when compared with central plant cooling from an air handler , eliminate

SECTION 50

#1732773223166

3900-400: The gas. The gas enters at the suction side and moves through the threads as the screws rotate. The meshing rotors force the gas through the compressor, and the gas exits at the end of the screws. The working area is the inter-lobe volume between the male and female rotors. It is larger at the intake end, and decreases along the length of the rotors until the exhaust port. This change in volume is

3975-408: The heat pump is in heating mode, the indoor evaporator coil switches roles and becomes the condenser coil, producing heat. The outdoor condenser unit also switches roles to serve as the evaporator and discharges cold air (colder than the ambient outdoor air). Most air source heat pumps become less efficient in outdoor temperatures lower than 4 °C or 40 °F. This is partly because ice forms on

4050-400: The heat pump is used efficiently during milder temperatures, and the system is switched to the conventional heat source when the outdoor temperature is lower. The coefficient of performance (COP) of an air conditioning system is a ratio of useful heating or cooling provided to the work required. Higher COPs equate to lower operating costs. The COP usually exceeds 1; however, the exact value

4125-465: The liquefied ammonia was allowed to evaporate. In 1842, Florida physician John Gorrie used compressor technology to create ice, which he used to cool air for his patients in his hospital in Apalachicola, Florida . He hoped to eventually use his ice-making machine to regulate the temperature of buildings. He envisioned centralized air conditioning that could cool entire cities. Gorrie was granted

4200-399: The middle of the vehicle. These are designed to allow quick dismounting and boarding of troops even while the vehicle is on the move. The eight wheels are located as two sets, with two pairs at the front of the hull and two pairs at the rear. Split-side doors are located between these two sets of wheels. The two forward pairs of wheels use power steering . The BTR-90 is capable of achieving

4275-403: The most common type of individual room air conditioner: one designed to sit on a window ledge. The units went on sale in 1932 at US$ 10,000 to $ 50,000 (the equivalent of $ 200,000 to $ 1,100,000 in 2023.) A year later, the first air conditioning systems for cars were offered for sale. Chrysler Motors introduced the first practical semi-portable air conditioning unit in 1935, and Packard became

4350-718: The nation’s premier air conditioning companies, builders, and social scientists. In addition, researchers from UT’s Health Service and Psychology Department studied the effects on the "artificially cooled humans." One of the more amusing discoveries was that each family reported being troubled with scorpions, the leading theory being that scorpions sought cool, shady places. Other reported changes in lifestyle were that mothers baked more, families ate heavier foods, and they were more apt to choose hot drinks. Air conditioner adoption tends to increase above around $ 10,000 annual household income in warmer areas. Global GDP growth explains around 85% of increased air condition adoption by 2050, while

4425-404: The need for large cool air ducts, air handlers, and chillers; instead cool refrigerant is transported through much smaller pipes to the indoor units in the spaces to be conditioned, thus allowing for less space above dropped ceilings and a lower structural impact, while also allowing for more individual and independent temperature control of spaces. The outdoor and indoor units can be spread across

4500-430: The outdoor unit's heat exchanger coil, which blocks air flow over the coil. To compensate for this, the heat pump system must temporarily switch back into the regular air conditioning mode to switch the outdoor evaporator coil back to the condenser coil, to heat up and defrost. Therefore, some heat pump systems will have electric resistance heating in the indoor air path that is activated only in this mode to compensate for

4575-498: The remaining 15% can be explained by climate change . As of 2016 an estimated 1.6 billion air conditioning units were used worldwide, with over half of them in China and USA , and a total cooling capacity of 11,675 gigawatts. The International Energy Agency predicted in 2018 that the number of air conditioning units would grow to around 4 billion units by 2050 and that the total cooling capacity would grow to around 23,000 GW, with

SECTION 60

#1732773223166

4650-749: The shoulder angle at alpha/2 = 22.5 degrees. The common rifling twist rate for this cartridge is 455 mm (1 in 17.91 in), 8 grooves, ⌀ lands = 14.50 mm, ⌀ grooves = 14.95 mm. According to the official guidelines, the 14.5 × 114 mm case can handle up to 360 MPa (52,213 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to be certified for sale to consumers. Cartridges use lacquered steel cases and percussion primers. Some countries also use brass cartridge cases. The propellant consists of 28.8 g (1.02 oz) smokeless powder with seven tubes, designated as "5/7NA powder". Two different versions of bullet series are known,

4725-415: The spaces to be cooled which then duct or deliver cold air into the spaces to be conditioned, rather than ducting cold air directly to these spaces from the plant, which is not done due to the low density and heat capacity of air, which would require impractically large ducts. The chilled water is cooled by chillers in the plant, which uses a refrigeration cycle to cool water, often transferring its heat to

4800-427: The surrounding air. An air conditioner designed for an occupied space will typically achieve a 30% to 60% relative humidity in the occupied space. Most modern air-conditioning systems feature a dehumidification cycle during which the compressor runs. At the same time, the fan is slowed to reduce the evaporator temperature and condense more water. A dehumidifier uses the same refrigeration cycle but incorporates both

4875-412: The temperature and humidity, which helped maintain consistent paper dimensions and ink alignment at the printing plant. Later, together with six other employees, Carrier formed The Carrier Air Conditioning Company of America , a business that in 2020 employed 53,000 people and was valued at $ 18.6 billion. In 1906, Stuart W. Cramer of Charlotte, North Carolina , was exploring ways to add moisture to

4950-437: The temperature of an object past the freezing point of water. They experimented with the bulb of a mercury-in-glass thermometer as their object. They used a bellows to speed up the evaporation . They lowered the temperature of the thermometer bulb down to −14 °C (7 °F) while the ambient temperature was 18 °C (64 °F). Franklin noted that soon after they passed the freezing point of water 0 °C (32 °F),

5025-405: The temporary indoor air cooling, which would otherwise be uncomfortable in the winter. Newer models have improved cold-weather performance, with efficient heating capacity down to −14 °F (−26 °C). However, there is always a chance that the humidity that condenses on the heat exchanger of the outdoor unit could freeze, even in models that have improved cold-weather performance, requiring

5100-646: The term and incorporated it into the name of his company. Domestic air conditioning soon took off. In 1914, the first domestic air conditioning was installed in Minneapolis in the home of Charles Gilbert Gates . It is, however, possible that the considerable device (c. 2.1 m × 1.8 m × 6.1 m; 7 ft × 6 ft × 20 ft) was never used, as the house remained uninhabited (Gates had already died in October 1913.) In 1931, H.H. Schultz and J.Q. Sherman developed what would become

5175-429: The traverse arms have high capacity telescopic hydraulic shock absorbers . Communication equipment installed in the BTR-90 include an R-163-50U radio set for external communications, an R-163UP receiver, and an R-174 intercom device for communication between the crew members. The commander and gunner are accommodated in a fighting compartment in the turret. This compartment houses a BPK-3-42 gunner's day/night sight and

5250-504: The vehicle is damaged while afloat, a drainage system is capable of removing incoming water. The BTR-90 features an automatic fire fighting system, and a system for the remote laying of smoke screens. The smoke discharge system includes six smoke grenade launchers, three on each side of the vehicle. The main gun of the BTR-90 is a 30 mm Shipunov 2A42 auto cannon. The vehicle carries an ammunition load of 500 rounds for this weapon. A 7.62 mm PKT coaxial machine gun with 2,000 rounds and

5325-603: The vehicle to increase protection. Active protection methods can be used, such as explosive reactive armour . These can be added over the existing armour of the vehicle. To increase protection, periscopes are installed instead of windscreens and vision blocks. Collective NBC (Nuclear, Biological and Chemical) protection is available which can protect the occupants from shock waves and penetrating radiation from nuclear attacks, radioactive dust , and bacteriological and chemical weapons . Its combat tires are capable of enduring anti-personnel mine explosions and small arms fire. If

5400-537: The water in a bucket or tray and stops when full. The air-to-air type re-evaporates the water, discharges it through the ducted hose, and can run continuously. Many but not all portable units draw indoor air and expel it outdoors through a single duct, negatively impacting their overall cooling efficiency. Many portable air conditioners come with heat as well as a dehumidification function. The packaged terminal air conditioner (PTAC), through-the-wall, and window air conditioners are similar. These units are installed on

5475-551: The water. The BTR-90 can be deployed by truck, rail and by water and air transportation means. Its hydro mechanical transmission helps to increase its maneuverability by providing different speeds to each side of the vehicle. This allows the BTR-90 to have a low turning radius of 6 m. When turning with only the front four wheels, it has a turning radius of 14 m. It can cross up to 2.1 m wide trenches and can negotiate 60% gradients, 30% side slopes and 0.8 m vertical steps. The vehicle has an inner capacity of 12 cubic meters, and can carry

5550-518: The weapons to be used while the vehicle is moving, and in all weather conditions. The turret can be traversed 360 degrees with an elevation range of −5 to +75 degrees. The vehicle's weaponry allows it to engage targets at ranges up to 4 km. Helicopters and fortifications can be engaged at ranges up to 2.5 km. In addition to the vehicle's weapons, its occupants have the ability to fire their weapons through available firing ports and hatches, increasing its firepower. A prototype designated BTR-90M

5625-480: Was built with a larger turret derived from the BMP-3 , mounting a coaxial low-velocity 2A70 100mm rifled gun/missile launcher system (which can fire conventional shells or laser beam-riding 9M117 anti-tank missiles ( ATGM ), such as AT-10 Stabber ), a 30mm Shipunov 2A72 cannon , and a 7.62mm PKT machine gun . The BTR-90M was first displayed publicly in 2001, and is not currently in service. Another variant of

#165834