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Hydronics is the name for the use of water as the heat-transfer medium in heating and cooling systems. Impact of a drop of water. ...
A heating system is a mechanism for maintianing temperatures at an acceptable level within a home, office, or other dwelling. ...
Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. ...
Some of the oldest and most common examples are steam or hot-water radiators. In large-scale commercial buildings such as high-rise and campus facilities, a hydronics system may include both a chilled and a heated water loop, to provide for both heating and air conditioning. Chillers and cooling towers are used separately or together as means to provide water cooling, while boilers heat water. In addition, many larger cities have a district heating system that provides, through underground piping, publicly available steam and chilled water. By paying a service fee, a building in the service district may be connected to these. It has been suggested that this article be split into articles entitled steam and water vapor, accessible from a disambiguation page. ...
A radiator is any device that emits a form of radiation. ...
High-rise is a 1975 novel by J. G. Ballard. ...
The Universitätscampus Wien, Austria ( details) Campus (plural: campuses) is derived from the (identical) Latin word for field or open space. English gets the words camp and campus from this origin. ...
Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. ...
York International water-cooled chiller. ...
Image 1: Natural draft wet cooling towers at Didcot Power Station, UK Cooling towers are evaporative coolers used for cooling water or other working medium to near the ambient wet-bulb air temperature. ...
A boiler is a closed vessel in which water or other fluid is heated under pressure. ...
District heating (less commonly called teleheating) is a system for distributing heat generated in a centralized location for residential and commercial heating requirements. ...
Hydronic systems may be divided into several general categories:
- Single-pipe steam
- Two-pipe steam
- Water loops
Single-pipe steam
 Single-pipe steam radiator The oldest modern hydronic heating technology, a single-pipe steam system delivers steam to the radiators where the steam gives up its heat and is condensed back to water. The radiators and steam supply pipes are pitched so that gravity eventually takes this condensate back down through the steam supply piping to the boiler where it can once again be turned into steam and returned to the radiators. Image File history File links Download high-resolution version (400x700, 38 KB)One-pipe steam radiator. ...
Image File history File links Download high-resolution version (400x700, 38 KB)One-pipe steam radiator. ...
Radiators and convectors are types of heat exchangers designed to transfer thermal energy from one medium to another for the purpose of cooling and heating. ...
Water vapor condensing over a cup of hot tea Condensation is the change in matter of a substance to a denser phase, such as a gas (or vapor) to a liquid. ...
Gravity is a force of attraction that acts between bodies that have mass. ...
Despite its name, a steam radiator does not primarily heat a room by radiation. If positioned correctly a radiator will create an air convection current in the room, which will provide the main heat transfer mechanism. It is generally agreed that for the best results a steam radiator should be no more than one to two inches from a wall.
Single-pipe systems are limited in both their ability to deliver high volumes of steam (that is, heat) and the ability to control the flow of steam to individual radiators (because closing off the steam supply traps condensate in the radiators). Because of these limitations, single-pipe systems are no longer installed.
Two-pipe steam systems In two-pipe steam systems, there is a separate return path for the condensate and it may involve pumps as well as gravity-induced flow. The flow of steam to individual radiators can be modulated using manual or automatic valves. A condensate pump is a specific type of pump used to pump the condensate (water) produced in an HVAC (heating or cooling) or refrigeration system. ...
These water valves are regulated by handles. ...
Very large scale systems can be built using the two-pipe principle. For example, rather than heating individual radiators, the steam may be used in the reheat coils of large air handlers to heat an entire floor of a building. All-air and air-water HVAC systems use air ducts, outlets, and inlets installed throughout their buildings. ...
Water loops Modern systems often use heated water rather than steam. This opens the system to the possibility of also using chilled water to provide air conditioning. Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. ...
In homes, the water loop may be as simple as a single pipe that "loops" the flow through every radiator in a zone. In such a system, flow to the individual radiators can not be modulated as all of the water is flowing through every radiator in the zone. Slightly more complicated systems use a "main" pipe that flows uninterrupted around the zone; the individual radiators tap off a small portion of the flow in the main pipe. In these systems, individual radiators can be modulated. Alternatively, a number of loops with several radiators can be installed, the flow in each loop or zone controlled by a zone valve connected to a thermostat. A zone valve is a specific type of valve used to control the flow of water or steam in a hydronic heating or cooling system. ...
Bi-metallic thermostat for buildings A thermostat is a device for regulating the temperature of a system so that the systems temperature is maintained near a desired setpoint temperature. ...
In any water system, the water is circulated by means of one or more circulator pumps. This is in marked contrast to steam systems where the inherent pressure of the steam is sufficient to distribute the steam to remote points in the system. A system may be broken up into individual heating zones using either multiple circulator pumps or a single pump and electrically operated zone valves. A circulator pump is a specific type of pump used to circulate gases, liquids, or slurries in a closed circuit. ...
A zone valve is a specific type of valve used to control the flow of water or steam in a hydronic heating or cooling system. ...
Boiler water treatment Domestic (home) systems may use ordinary tap water, but sophisticated commercial systems often add various chemicals to the system water. For example, these added chemicals may: Corrosion is deterioration of essential properties in a material due to reactions with its surroundings. ...
A man pouring antifreeze into his vehicle. ...
It has been suggested that Toxic mold be merged into this article or section. ...
Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ...
Yarn drying after being dyed in the early American tradition, at Conner Prairie living history museum. ...
Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ...
Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ...
Air Elimination All hydronic systems must have a means to eliminate air from the system. A properly designed system that is air-free should provide many years of excellent performance.
Air causes irritating system noise in addition to interrupting proper heat transfer as the system fluids circulate throughout the system. In addition, unless reduced below an acceptable level, the oxygen found within water will cause corrosion. This corrosion can cause rust and scale to build up on the system piping. Over time these particles can become loose and travel throughout the system. The particles can reduce flow and even clog the system in addition to causing damage to pump seals and other system components. General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ...
Corrosion is deterioration of essential properties in a material due to reactions with its surroundings. ...
In steam systems, individual radiators are usually equipped with a thermostatic bleed valve. At room temperature, the valve opens the radiator to the air, but as hot steam flows into the radiator and pushes the contained air out, the valve heats and eventually closes, preventing steam from escaping into the room.
Water-loop systems can also experience air problems. Air found within hydronic water-loop systems may be classified into three forms:
1. Free air. Various devices such as manual and automatic air vents are used to address Free air which floats up to the high points throughout the system. Automatic air vents contain a valve that is operated by a float. When air is present, the float drops, allowing the valve to open and bleed air out. When water reaches (fills) the valve, the float lifts, blocking the water from escaping. Small (domestic) versions of these valves in older systems are sometimes fitted with a Schraeder-type air valve fitting and any trapped, now-compressed air can be bled from the valve by manually depressing the valve stem until water rather than air begins to emerge. A schrader valve (with cap) on a bicycle tire A keyed schrader valve cap used for removing/inserting the valves Unusually tall schrader valve The Schrader Valve is a valve stem invented by August Schrader and is used on virtually all automobile tires and wider rimmed (lower pressure) bicycle tires. ...
2. Entrained air. Entrained air is the air bubbles that travel around in the piping at the same velocity as the water. Air "scoops" are one example of products which attempt to remove this type of air.
3. Dissolved air. Dissolved air is also present in the system water and the amount is determined principally by the temperature and pressure (see Henry's Law) of the incoming water. On average tap water contains between 8-10% dissolved air by volume. Removal of Dissolved air and Free / Entrained air can be achieved with a high-efficiency air elimination device that includes a coalescing medium that continually scrubs the air out of the system. In chemistry, Henrys law is one of the gas laws, formulated by William Henry. ...
Accommodating thermal expansion Water expands and contracts as it heats and cools. A water-loop hydronic system must have one or more expansion tanks in the system to accommodate this varying volume of the working fluid. These tanks often use a rubber diaphragm pressurised with compressed air. The expansion tank accommodates the expanded water by further air compression and helps maintain a roughly-constant pressure in the system across the expected change in fluid volume. Compressed air is used to refer to: Pneumatics, the use of pressurized gases to do work, as used in the Air car Breathing gas, often used in scuba diving, also to inflate buoyancy devices Compressed air can also be used for cooling using a vortex tube. ...
Automatic fill mechanisms Hydronic systems are usually connected to a water supply (such as the public water supply). An automatic valve regulates the amount of water in the system and also prevents backflow of system water (and any water treatment chemicals!) into the water supply. A backflow prevention device is used to protect water supplies from contamination. ...
Safety mechanisms Excessive heat or pressure may cause the system to fail. At least one combination over-temperature and over-pressure relief valve is always fitted to the system to allow the steam or water to vent to the atmosphere in case of the failure of some mechanism (such as the boiler temperature control) rather than allowing the catastrophic bursting of the piping, radiators, or boiler. The relief valve usually has a manual operating handle to allow testing and the flushing of contaminants (such as grit) that may cause the valve to leak under otherwise-normal operating conditions. Relief Valve A relief valve opens to release excess pressure when the pressure is too high to protect the vessel or other equipment from overpressurization. ...
See also Radiant heating is a heating system which heats a building through radiant heat, rather than other conventional methods including convection heating. ...
A boiler is a closed vessel in which water or other fluid is heated under pressure. ...
York International water-cooled chiller. ...
External links - radiantpanelassociation.com
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