Misplaced Pages

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82-442: Because water could not circulate in the lake as it is fed by springs and surface water, and because of nutrients introduced by plant growth and bathers, there was a risk of life in the lake dying out. This could only be prevented in summer 2013 by the intervention of the fire service who enriched the lake water by spraying it with oxygen. Thereafter the leaseholders of the lake, Sinzheim Sports Fishing Club, with financial support from

164-542: A closed circuit with small elevation changes. They are commonly found circulating water in a hydronic heating or cooling system. They are specialized in providing a large flow rate rather than providing much head , as they are supposed to only overcome the friction of a piping system, as opposed to a regular centrifugal pump which may need to lift a fluid significantly. Circulator pumps as used in hydronic systems are usually electrically powered centrifugal pumps. As used in homes, they are often small, sealed, and rated at

246-476: A continual supply of hot water are called water heaters , hot water heaters , hot water tanks , boilers , heat exchangers , geysers (Southern Africa and the Arab world), or calorifiers . These names depend on region, and whether they heat potable or non-potable water, are in domestic or industrial use, and their energy source. In domestic installations, potable water heated for uses other than space heating

328-738: A continuous flow of hot water at extremely low flow rates, unlike high-capacity tankless heaters. In tropical countries like Singapore and India, a storage water heater may vary from 10 L to 35 L. Smaller water heaters are sufficient, as ambient weather temperatures and incoming water temperature are moderate. The Coldest regions in India like Kashmir, people are mostly dependent on the storage type electric water heaters. Mostly 50L or 75L Storage type electric water heaters are connected to overhead water source. A locational design decision may be made between point-of-use and centralized water heaters. Centralized water heaters are more traditional, and are still

410-456: A continuously operating pump which consumes more electrical energy. Reduced energy waste and discomfort is possible by preventing occurrences of hot water line siphoning in open-loop hot water circulation systems which utilize the cold water line to return water back to the water heater. Hot Water Line Siphoning occurs when water from within the hot water line siphons or is forced into the cold water line due to differences in water pressure between

492-628: A continuously operating pump. By installing a thermostatically controlled pump just after the farthest fixture on the loop, cyclic pumping maintains ready hot water up to the last fixture on the loop instead of wasting energy heating the piping from the last fixture to the water heater. Installing a circulation pump at the farthest fixture on a hot water circulation loop is often not feasible due to limited available space, cosmetics, noise restrictions or lack of available power. Recent advancements in hot water circulation technology allow for benefiting from temperature controlled pumping without having to install

574-475: A cylindrical vessel or container that keeps water continuously hot and ready to use. Typical sizes for household use range from 75 to 400 L (20 to 100 US gallons). These may use electricity , natural gas , propane , heating oil , solar , or other energy sources. Natural gas heaters are most popular in the US and most European countries, since the gas is often conveniently piped throughout cities and towns and currently

656-568: A disappointingly small amount of water: about 0.17 US gal (0.64 L) per minute at 40 °C (72 °F) temperature elevation. The energy used by an electric water heater can be reduced by as much as 18% through optimal schedule and temperature control that is based on knowledge of the usage pattern. On April 16, 2015, as part of the National Appliance Energy Conservation Act (NAECA), new minimum standards for efficiency of residential water heaters set by

738-411: A fraction of a horsepower , but in commercial applications they range in size up to many horsepower and the electric motor is usually separated from the pump body by some form of mechanical coupling. The sealed units used in home applications often have the motor rotor, pump impeller, and support bearings combined and sealed within the water circuit. This avoids one of the principal challenges faced by

820-595: A good flow . In most other parts of the world, water heating appliances do not use a cold water storage vessel or container, but heat water at pressures close to that of the incoming mains water supply. Other improvements to water heaters include check valve devices at their inlet and outlet, cycle timers, electronic ignition in the case of fuel-using models, sealed air intake systems in the case of fuel-using models, and pipe insulation. The sealed air-intake system types are sometimes called "band- joist " intake units. "High-efficiency" condensing units can convert up to 98% of

902-403: A good choice for small buildings. For larger buildings with intermittent or occasional hot water use, multiple POU water heaters may be a better choice, since they can reduce long waits for hot water to arrive from a remote heater. The decision where to locate the water heater(s) is only partially independent of the decision of a tanked vs. tankless water heater , or the choice of energy source for

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984-416: A hair dryer. Electric showers have a simple electric system, working like a coffee maker, but with a larger water flow. A flow switch turns on the device when water flows through it. Once the water is stopped, the device turns off automatically. An ordinary electric shower often but not always has three heat settings: high (5.5 kW), low (2.5 kW), or cold (0 W) to use when a central heater system

1066-447: A house fire or explosion. The second feature prevents tank overheating due to unusual combustion conditions. These safety requirements were made in response to homeowners storing, or spilling, gasoline or other flammable liquids near their water heaters and causing fires. Since most of the new designs incorporate some type of flame arrestor screen, they require monitoring to make sure they do not become clogged with lint or dust, reducing

1148-459: A household at more than one point-of-use (POU), far from a central water heater, or larger centralized models may still be used to provide all the hot water requirements for an entire house. The main advantages of tankless water heaters are a plentiful continuous flow of hot water (as compared to a limited flow of continuously heated hot water from conventional tank water heaters), and potential energy savings under some conditions. The main disadvantage

1230-441: A nominal input of 22 kW (75,000 BTU/h) or less was able to have an energy factor as low as 53%, while under the 2015 standard, the minimum energy factor for a 75-US-gallon gas storage tank water heater is now 74%, which can only be achieved by using condensing technology. Storage water heaters with a nominal input of 22 kW (75,000 BTU/h) or greater are not currently affected by these requirements, since energy factor

1312-578: A rack, evacuated tube collectors form a row of glass tubes, each containing absorption fins attached to a central heat-conducting rod (copper or condensation-driven). The evacuated description refers to the vacuum created in the glass tubes during the manufacturing process, which results in very low heat loss and lets evacuated tube systems achieve extreme temperatures, far in excess of water's boiling point. In countries like Iceland and New Zealand , and other volcanic regions, water heating may be done using geothermal heating , rather than combustion. Where

1394-542: A return has the disadvantage of heating the cold water pipe (and the contained water). Accurate temperature monitoring and active flow control can minimize loss of cold water within the cold water line. Technological advancements within the industry allow for incorporating timers to limit the operations during specific hours of the day to reduce energy waste by only operating when occupants are likely to use hot water. Additional advancements in technology include pumps which cycle on and off to maintain hot water temperature versus

1476-402: A short time after a user's request for hot water. In regions where water conservation issues are rising in importance with rapidly expanding and urbanizing populations local water authorities offer rebates to homeowners and builders that install a circulator pump to save water. In typical one-way plumbing without a circulation pump, water is simply piped from the water heater through the pipes to

1558-435: A sink. They typically use low power heating elements , about 1 kW to 1.5 kW, and can provide hot water long enough for hand washing, or, if plumbed into an existing hot water line, until hot water arrives from a remote high capacity water heater. They may be used when retrofitting a building with hot water plumbing is too costly or impractical. Since they maintain water temperature thermostatically, they can only supply

1640-493: A space-heating water boiler is employed, the traditional arrangement in the UK and Ireland is to use boiler-heated ( primary ) water to heat potable ( secondary ) water contained in a cylindrical vessel (usually made of copper)—which is supplied from a cold water storage vessel or container, usually in the roof space of the building. This produces a fairly steady supply of DHW (domestic hot water) at low static pressure head but usually with

1722-665: A tankless heater, would take about 15 minutes to do this. At $ 1 per therm , the cost of the gas would be about 40 cents. In comparison, a typical 230 L (60 US gal) tank electric water heater has a 4.5 kW (15,000 BTU/h) heating element, which at 100% efficient results in a heating time of about 2.34 hours. At $ 0.16/kWh the electricity would cost $ 1.68. Energy efficiencies of water heaters in residential use can vary greatly, particularly depending on manufacturer and model. However, electric heaters tend to be slightly more efficient (not counting power station losses) with recovery efficiency (how efficiently energy transfers to

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1804-399: A water heater specifically designed for solar thermal. In Cyprus and Israel 90 percent of homes have solar water heating systems. The most basic solar thermal models are the direct-gain type, in which the potable water is directly sent into the collector. Many such systems are said to use integrated collector storage (ICS), as direct-gain systems typically have storage integrated within

1886-616: Is a significant delay before hot water is available again. Larger tanks tend to provide hot water with less temperature fluctuation at moderate flow rates. Volume storage water heaters in the United States and New Zealand are typically vertical cylindrical tanks, usually standing on the floor, a 'cylinder tray' or on a platform raised a short distance above the floor. Volume storage water heaters in Spain are typically horizontal. In India, they are mainly vertical. In apartments they can be mounted in

1968-685: Is also called domestic hot water ( DHW ). Fossil fuels ( natural gas , liquefied petroleum gas , oil ), or solid fuels are commonly used for heating water. These may be consumed directly or may produce electricity that, in turn, heats water. Electricity to heat water may also come from any other electrical source, such as nuclear power or renewable energy . Alternative energy such as solar energy , heat pumps , hot water heat recycling , and geothermal heating can also heat water, often in combination with backup systems powered by fossil fuels or electricity. Densely populated urban areas of some countries provide district heating of hot water. This

2050-622: Is available or in hot seasons. Higher power (up to 7.5 KW) and lower power (up to 3.2 KW) versions are also made, as well as versions with 4 heat settings or a variable heat setting. Recent advancements in solar water heaters, such as evacuated tube collectors, have significantly improved efficiency, especially in colder climates." (Source: Solar Water Heating - Misplaced Pages ). It should also be mentioned that Countries like China lead in solar water heating adoption, accounting for over 70% of global capacity." (Source: Solar Water Heating - Misplaced Pages ) The power consumption of electric showers in

2132-459: Is especially the case in Scandinavia , Finland and Poland . District heating systems supply energy for water heating and space heating from combined heat and power (CHP) plants such as incinerators , central heat pumps, waste heat from industries, geothermal heating, and central solar heating . Actual heating of tap water is performed in heat exchangers at the consumers' premises. Generally

2214-409: Is not defined for such units. An 80 US gal (300 L; 67 imp gal) electric storage tank water heater was able to have a minimum energy factor of 86% under the pre-2015 standard, while under the 2015 standard, the minimum energy factor for an 80-gallon electric storage tank water heater is now 197%, which is only possible with heat pump technology. This rating measures efficiency at

2296-631: Is often measured by volume or heat content. Common units of measurement by volume are cubic metre or cubic feet at standard conditions or by heat content in kilowatt hours , British thermal units (BTU) or therm , which is equal to 100,000 BTU. A BTU is the energy required to raise one pound of water by one degree Fahrenheit. A US gallon of water weighs 8.3 pounds (3.8 kg). To raise 230 L (60 US gal) of water from 10 °C (50 °F) to 50 °C (122 °F) at 90% efficiency requires 60 × 8.3 × (122 − 50) × 1.11 = 39,840 BTU . A 46 kW (157,000 BTU/h) heater, as might exist in

2378-522: Is often not sheathed and electrically isolated, in which case isolation is provided by earthing electrodes that directly touch the water before it exits the head. Electric shower heads with sheathed and electrically isolated heating elements are often marketed as such ( chuveiros blindados in Portuguese) and are more expensive. Due to electrical safety standards as well as cost, modern electric showers are made of plastic instead of using metallic casings like in

2460-418: Is often the case) may be dangerous, as the wires can overheat or electric current may leak via the water stream through the body of the user to earth. Increasingly, solar powered water heaters are being used. Their solar collectors are installed outside dwellings, typically on the roof or walls or nearby, and the potable hot water storage tank is typically a pre-existing or new conventional water heater, or

2542-507: Is repeated used as a film location. For example, in 1984 in the four-part historical series, The Lenz Papers  [ de ] , where it represented Hell Valley , in several episodes of the TV crime series Tatort and in 2010 as the scene of the showdown in the thriller, The Good Neighbour . Circulator pump A circulator pump or circulating pump is a specific type of pump used to circulate gases , liquids , or slurries in

Waldenecksee - Misplaced Pages Continue

2624-554: Is set up to heat a separate hot water cylinder or water heater for potable hot water. Such water heaters are often fitted with an auxiliary electrical immersion heater for use if the boiler is out of action for a time. Heat from the space-heating boiler is transferred to the water heater vessel/container by means of a heat exchanger, and the boiler operates at a higher temperature than the potable hot water supply. Most potable water heaters in North America are completely separate from

2706-534: Is still sometimes called a geyser in the UK and South Africa. Maughn's invention influenced the work of a Norwegian mechanical engineer named Edwin Ruud . The first automatic, storage tank-type gas water heater was invented around 1889 by Ruud after he immigrated to Pittsburgh , Pennsylvania (US). The Ruud Manufacturing Company, still in existence today, made many advancements in tank-type and tankless water heater design and operation. Water typically enters residences in

2788-419: Is the cheapest to use. In the United States, typical natural gas water heaters for households without unusual needs are 150–190 L (40–50 US gal) with a burner rated at 10.0–11.7 kilowatts (34,000–40,000 BTU/h). This is a popular arrangement where higher flow rates are required for limited periods. Water is heated in a pressure vessel that can withstand a hydrostatic pressure close to that of

2870-411: Is the energy wasted in operating the pump and the additional demand on the water heater to make up for the heat lost from the constantly hot pipes. While the majority of these pumps mount nearest to the hot water heater and have no adjustable temperature capabilities, a significant reduction in energy can be achieved by using a temperature adjustable thermostatically controlled circulation pump mounted at

2952-580: Is the subject of pump manufacturers warranty. As from 1 January 2013, circulators must comply with European regulation 641/2009. This regulation is part of the ecodesign policy of the European Union. Water heating Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating. In industry, hot water and water heated to steam have many uses. Domestically, water

3034-824: Is their much higher initial costs; a US study in Minnesota reported a 20- to 40-year payback for the tankless water heaters. In a comparison to a less efficient natural gas fired hot water tank, on-demand natural gas will cost 30% more over its useful life. Stand-alone appliances for quickly heating water for domestic usage are known in North America as tankless or on demand water heaters. In some places, they are called multipoint heaters , geysers or ascots . In Australia and New Zealand they are called instantaneous hot water units . In Argentina they are called calefones . In that country calefones use gas instead of electricity, although gas powered tankless water heaters can also be found in other countries. A similar wood-fired appliance

3116-411: Is traditionally heated in vessels known as water heaters , kettles , cauldrons , pots , or coppers . These metal vessels that heat a batch of water do not produce a continual supply of heated water at a preset temperature. Rarely, hot water occurs naturally, usually from natural hot springs . The temperature varies with the consumption rate, becoming cooler as flow increases. Appliances that provide

3198-741: Is usually achieved using an intermittent pilot together with an automatic flue damper, baffle blowers, or power venting. Direct electric resistance tank water heaters are not included in the Energy Star program; however, the Energy Star program does include electric heat pump units with energy factors of 200% or higher. Tankless gas water heaters (as of 2015) must have an energy factor of 90% or higher for Energy Star qualification. Since electricity production in thermal plants has efficiency levels ranging from only 15% to slightly over 55% ( combined cycle gas turbine), with around 40% typical for thermal power stations, direct resistance electric water heating may be

3280-565: The United States Department of Energy went into effect. All new gas storage tank water heaters with capacities smaller than 55 US gal (210 L; 46 imp gal) sold in the United States in 2015 or later shall have an energy factor of at least 60% (for 50-US-gallon units, higher for smaller units), increased from the pre-2015 minimum standard of 58% energy factor for 50-US-gallon gas units. Electric storage tank water heaters with capacities less than 55 US gallons sold in

3362-453: The 1940s, the electric shower is a home appliance often seen in South and Central American countries due to the higher costs of gas distribution, combined with households that in most cases do not support conventional water heaters. Earlier models were made of chromed copper or brass, which were expensive, but since 1970, units made of injected plastics are popular due to low prices similar to that of

Waldenecksee - Misplaced Pages Continue

3444-557: The Lichtental Formation, which is composed of remains of a volcano that is almost 300 million years old. The Baden-Württemberg State Office for Geology, Raw Materials and Mining ( Landesamt für Geologie, Rohstoffe und Bergbau Baden-Württemberg ) classifies the abandoned Waldeneck Quarry as a valuable geotope . The terrain of the quarry and lake, which is about 2 kilometres from the Baden-Baden broadcasting studio of Südwestrundfunk

3526-531: The US at about 10 °C (50 °F), depending on latitude and season. Hot water temperatures of 50 °C (122 °F) are usual for dish-washing, laundry and showering, which requires that the heater raise the water temperature about 40 °C (72 °F) if the hot water is mixed with cold water at the point of use. The Uniform Plumbing Code reference shower flow rate is 9.5 L (2.5 US gal) per minute. Sink and dishwasher usages range from 4–11 L (1–3 US gal) per minute. Natural gas

3608-454: The United States shall have an energy factor of at least 95%, increased from the pre-2015 minimum standard of 90% for 50-US-gallon electric units. Under the 2015 standard, for the first time, storage water heaters with capacities of 55 US gallons or larger now face stricter efficiency requirements than those of 50 US gallons or less. Under the pre-2015 standard, a 75 US gal (280 L; 62 imp gal) gas storage water heater with

3690-403: The advantage of using energy (gas or electricity) at a relatively slow rate, storing the heat for later use. The disadvantage is that over time, heat escapes through the tank wall and the water cools down, activating the heating system to heat the water back up, so investing in a tank with better insulation improves this standby efficiency. Additionally, when heavy use exhausts the hot water, there

3772-419: The availability of air for combustion. If the flame arrestor becomes clogged, the thermal cutoff may act to shut down the heater. A wetback stove ( NZ ), wetback heater (NZ), or back boiler (UK), is a simple household secondary water heater using incidental heat. It typically consists of a hot water pipe running behind a fireplace or stove (rather than hot water storage ), and has no facility to limit

3854-458: The boiler, or by an electric immersion heater (often as backup to the boiler). In the UK these vessels are called indirect cylinders and direct cylinders , respectively. Additionally, if these cylinders form part of a sealed system, providing mains-pressure hot water, they are known as unvented cylinders. In the US, when connected to a boiler, they are called indirect-fired water heaters . Compared to tankless heaters, storage water heaters have

3936-408: The ceiling space over laundry-utility rooms. In Australia, gas and electric outdoor tank heaters have mainly been used (with high temperatures to increase effective capacity), but solar roof tanks are becoming fashionable. Tiny point-of-use (POU) electric storage water heaters with capacities ranging from 8–32 L (2–6 gallons) are made for installation in kitchen and bath cabinets or on the wall above

4018-501: The circulation pumps. In a drainback system, the water drains into a storage tank contained in conditioned or semi-conditioned space, protected from freezing temperatures. With antifreeze systems, however, the pump must be run if the panel temperature gets too hot (to prevent degradation of the antifreeze) or too cold (to prevent the water/antifreeze mixture from freezing.) Flat panel collectors are typically used in closed-loop systems. Flat panels, which often resemble skylights , are

4100-410: The collector. Heating water directly is inherently more efficient than heating it indirectly via heat exchangers, but such systems offer very limited freeze protection (if any), can easily heat water to temperatures unsafe for domestic use, and ICS systems suffer from severe heat loss on cold nights and cold, cloudy days. By contrast, indirect or closed-loop systems do not allow potable water through

4182-474: The consumer has no in-building backup system as redundancy is usually significant on the district heating supply side. Today, in the United States, domestic hot water used in homes is most commonly heated with natural gas, electric resistance, or a heat pump. Electric heat pump water heaters are significantly more efficient than electric resistance water heaters, but also more expensive to purchase. Some energy utilities offer their customers funding to help offset

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4264-436: The energy demand on the water heater. It is important to take note of the increased heat in the piping system, which in turn increases system pressure. Piping that is sensitive to the water condition (i.e., copper, and soft water) will be adversely affected by the continual flow. Although water is conserved, the parasitic heat loss through the piping will be greater as a result of the increased heat passing through it. During

4346-409: The energy in the fuel to heating the water. The exhaust gases of combustion are cooled and are mechanically ventilated either through the roof or through an exterior wall. At high combustion efficiencies a drain must be supplied to handle the water condensed out of the combustion products, which are primarily carbon dioxide and water vapor. In traditional plumbing in the UK, the space-heating boiler

4428-400: The existing cold water line as return line from the point of use located farthest from the hot water tank back to the hot water tank. The first of two system types has a pump mounted at the hot water heater while a "normally open" thermostatic control valve gets installed at the farthest fixture from the water heater and closes once hot water contacts the valve to control crossover flow between

4510-423: The first instantaneous domestic water heater that did not use solid fuel . Named the geyser after an Icelandic gushing hot spring, Maughan's invention made cold water at the top flow through pipes that were heated by hot gases from a burner at the bottom. Hot water then flowed into a sink or tub. The invention was somewhat dangerous because there was no flue to remove heated gases from the bathroom. A water heater

4592-519: The graphical relationship between the values Q, ∆ p(∆H), P and η is used. These are called the pump curves. They are determined by studies, whose methodology is standardized. These curves are specified when water is pumped with a density of 1000 kg/m3 and kinematic viscosity of 1 mm2/s. When the circulating pump is used for liquids of different density and viscosity, the pump curves have to be recalculated. These curves are provided in catalogues and in operation and maintenance manuals, however their stroke

4674-500: The heat. Tankless water heaters—also called instantaneous, continuous flow, inline, flash, on-demand, or instant-on water heaters—are gaining in popularity. These high-power water heaters instantly heat water as it flows through the device, and do not retain any water internally except for what is in the heat exchanger coil. Copper heat exchangers are preferred in these units because of their high thermal conductivity and ease of fabrication. Tankless heaters may be installed throughout

4756-506: The heating. Modern wetbacks may run the pipe in a more sophisticated design to assist heat-exchange . These designs are being forced out by government efficiency regulations that do not count the energy used to heat water as 'efficiently' used. Another type of water heater developed in Europe predated the storage model. In London, England, in 1868, Benjamin Waddy Maughan , a painter, invented

4838-456: The higher first cost of energy efficient water heaters. Hot water used for space heating may be heated by fossil fuels in a boiler, while potable water may be heated in a separate appliance. This is common practice in the US, especially when warm-air space heating is usually employed. In household and commercial usage, most North American and Southern Asian water heaters are the tank type, also called storage water heaters . These consist of

4920-399: The hot and cold lines. A second type of system uses a thermostatically controlled pump which gets installed at the farthest fixture from the water heater. These thermostatically controlled pumps often have a built-in "normally closed" check-valve which prevents water in the cold water line from entering into the hot water line. Compared to a dedicated return line, using the cold water line as

5002-498: The hot and cold water lines. Utilizing "normally closed" solenoid valve significantly reduces energy consumption by preventing siphoning of non-hot water out of hot water lines during cold water use. Using cold water instantly lowers the water pressure in the cold water lines, the higher water pressure in the hot water lines force water through "normally open" thermostatic crossover valves and backflow check valves (which only prevent cold water from flowing into hot water line), increasing

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5084-448: The incoming mains supply. A pressure reducing valve is sometimes employed to limit the pressure to a safe level for the vessel. In North America, these vessels are called hot water tanks , and may incorporate an electrical resistance heater, a heat pump , or a gas or oil burner that heats water directly. Where hot-water space heating boilers are installed, domestic hot water cylinders are usually heated indirectly by primary water from

5166-405: The larger, two-part pumps: maintaining a water-tight seal at the point where the pump drive shaft enters the pump body. Small- to medium-sized circulator pumps are usually supported entirely by the pipe flanges that join them to the rest of the hydronic plumbing . Large pumps are usually pad-mounted. Pumps that are used solely for closed hydronic systems can be made with cast iron components as

5248-412: The last fixture on the loop. Thermostatically controlled circulation pumps allow owners to choose the desired temperature of hot water to be maintained within the hot water pipes since most homes do not require 120 °F (49 °C) degree water instantly out of their taps. Thermostatically controlled circulation pumps cycle on and off to maintain a user's chosen temperature and consume less energy than

5330-415: The least energy efficient option. However, use of a heat pump can make electric water heaters much more energy efficient and lead to a decrease in carbon dioxide emissions, even more so if a low carbon source of electricity is used. Using district heating utilizing waste heat from electricity generation and other industries to heat residences and hot water gives an increased overall efficiency, removing

5412-430: The max. heating setting is about 5.5 kW for 120 V and 7.5 kW for 220 V. The lower costs with electric showers compared to the higher costs with tank boilers is due to the time of use: an electric shower uses energy only while the water flows, while a tank boiler works many times a day to keep a quantity of standing water hot for use throughout the day and night. Moreover, the transfer of electric energy to

5494-490: The most durable type of collector, and they also have the best performance for systems designed for temperatures within 56 °C (100 °F) of ambient temperature . Flat panels are regularly used in both pure water and antifreeze systems. Another type of solar collector is the evacuated tube collector , which are intended for cold climates that do not experience severe hail and/or applications where high temperatures are needed (i.e., over 94 °C [201 °F]). Placed in

5576-597: The municipality of Sinzheim 2014, installed a solar-powered circulator pump , which pumps water from the lakebed to the surface. Quartz porphyry of the upper Rotliegendes is visible on the rock walls of the quarry. They are ignimbrite rhyolites , that is, pyroclastic volcanic rocks which have not flowed out as lava and cooled. but are formed from fluid suspensions of small magmatic particles in highly heated gases. Three of lava fields of ignimbrite of different colours and mineral composition are recognizable from bottom to top. The rocks are lithostratigraphically part of

5658-436: The need for burning fossil fuel or using high energy value electricity to produce heat in the individual home. Fundamentally, it takes a great deal of energy to heat water, as one may experience when waiting to boil a gallon of water on a stove. For this reason, tankless on-demand water heaters require a powerful energy source. A standard 120V, 15-ampere rated wall electric outlet, by comparison, only sources enough power to warm

5740-416: The panels, but rather pump a heat transfer fluid (either water or a water/antifreeze mix) through the panels. After collecting heat in the panels, the heat transfer fluid flows through a heat exchanger , transferring its heat to the potable hot water. When the panels are cooler than the storage tank or when the storage tank has already reached its maximum temperature, the controller in closed-loop systems stops

5822-410: The past. As an electrical appliance that uses more electric current than a clothes washer or a hair dryer, an electric shower installation requires careful planning, and generally is intended to be wired directly from the electrical distribution box with a dedicated circuit breaker and ground system. A poorly installed system with old aluminum wires, bad connections or an unconnected ground wire (which

5904-635: The point of use. Depending on how electricity is generated, overall efficiency may be much lower. For example, in a traditional coal plant, only about 30–35% of the energy in the coal ends up as electricity on the other end of the generator. Losses on the electrical grid (including line losses and voltage transformation losses) reduce electrical efficiency further. According to data from the Energy Information Administration, transmission and distribution losses in 2005 consumed 6.1% of net generation. In contrast, 90% of natural gas's energy value

5986-424: The pressure in the suction port (at the inlet of the pump) should be higher than the saturation pressure corresponding to the liquid temperature by the net positive suction head (NPSH). The following parameters are characteristic for the circulating pumps: capacity Q, pump pressure ∆p (delivery head ∆H), energy consumption P with pump unit efficiency η, impeller rotational speed n, NPSH and sound level L. In practice,

6068-479: The pump at the last fixture on the hot water loop. These advanced hot water circulation systems utilize a water contacting temperature probe strategically installed at the last fixture on the loop to minimize the energy wasted heating lengthy return pipes. Thermal insulation applied to the pipes helps mitigate this second loss and minimize the amount of water that must be pumped to keep hot water constantly available. The traditional hot water recirculation system uses

6150-407: The pump operation, there is a drop of the liquid flow in the center of the rotor, causing the inflow of the liquid through the suction port. In the event of an excessive pressure decrease, in some parts of the rotor, the pressure can be lower than the saturation pressure corresponding to the temperature of the pumped liquid, causing the so-called cavitation , i.e. liquid evaporation. To prevent this,

6232-502: The rate at which they can produce it is limited by the thermodynamics of heating water from the available fuel supplies. An electric shower head has an electric heating element which heats water as it passes through. These self-heating shower heads are specialized point-of-use (POU) tankless water heaters, and are widely used in some countries. Invented in Brazil in the 1930s due to a lack of central gas distribution and used frequently since

6314-445: The space heating units, due to the popularity of HVAC / forced air systems in North America. Residential combustion water heaters manufactured since 2003 in the United States have been redesigned to resist ignition of flammable vapors and incorporate a thermal cutoff switch, per ANSI Z21.10.1. The first feature attempts to prevent vapors from flammable liquids and gases in the vicinity of the heater from being ignited and thus causing

6396-404: The tap. Once the tap is shut off, the water remaining in the pipes cools producing the familiar wait for hot water the next time the tap is opened. By adding a circulator pump and constantly circulating a small amount of hot water through the pipes from the heater to the farthest fixture and back to the heater, the water in the pipes is always hot, and no water is wasted during the wait. The tradeoff

6478-418: The water in an electric shower head is very efficient, approaching 100%. Electric showers may save energy compared to electric tank heaters, which lose some standby heat. There is a wide range of electric shower heads, with various designs and types of heating controls. The heating element of an electric shower is immersed in the water stream, using an often replaceable nichrome resistive heating element which

6560-417: The water in the loop will either become de-oxygenated or be treated with chemicals to inhibit corrosion . But pumps that have a steady stream of oxygenated, potable water flowing through them must be made of more expensive materials such as bronze . Circulating pumps are often used to circulate domestic hot water so that a faucet will provide hot water instantly upon demand, or (more conserving of energy)

6642-571: The water) reaching about 98%. Gas-fired heaters have maximum recovery efficiencies of only about 82–94% (the remaining heat is lost with the flue gasses). Overall energy factors can be as low as 80% for electric and 50% for gas systems. Natural gas and propane tank water heaters with energy factors of 62% or greater, as well as electric tank water heaters with energy factors of 93% or greater, are considered high-efficiency units. Energy Star -qualified natural gas and propane tank water heaters (as of September 2010) have energy factors of 67% or higher, which

6724-402: Was known as the chip heater . A common arrangement where hot-water space heating is employed is for a boiler also to heat potable water , providing a continuous supply of hot water without extra equipment. Appliances that can supply both space-heating and domestic hot water are called combination (or combi ) boilers. Though on-demand heaters provide a continuous supply of domestic hot water,

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