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The classical mathematical puzzle known as the three utilities problem or sometimes water, gas and electricity asks for non-crossing connections to be drawn between three houses and three utility companies in the plane. When posing it in the early 20th century, Henry Dudeney wrote that it was already an old problem.
A water heater 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 ...
Tankless gas electronic ignition water heaters. Gas water heaters have an exhaust vent or one to two exhaust pipes on the top, and still require electric power for electronics, sensing and ignition. A three-phase, 21 kW, 400-volt tankless water heater in Europe, with new European color coding for three-phase power.
More than 352 thermochemical cycles have been described for water splitting by thermolysis. [21] These cycles promise to produce hydrogen and oxygen from water and heat without using electricity. [22] Since all the input energy for such processes is heat, they can be more efficient than high-temperature electrolysis.
Without the excess energy, electrolysis occurs slowly or not at all. This is in part due to the limited self-ionization of water. Pure water has an electrical conductivity about one hundred thousandth that of seawater. [8] [9] [10] Efficiency is increased through the addition of an electrolyte (such as a salt, an acid or a base) and ...
Thermosyphon circulation in a simple solar water heater (not a working model; there is no water supply to replenish the tank when the tap is used). A thermosiphon (or thermosyphon) is a device that employs a method of passive heat exchange based on natural convection, which circulates a fluid without the necessity of a mechanical pump.
The distribution network is more costly to build than for gas or electric heating, and so is only found in densely populated areas or compact communities. Not all central heating systems require purchased energy. A few buildings are served by local geothermal heat, using hot water or steam from a local well to provide building heat.
Heat needs to be added to the upper part of the bed, either by combusting small amounts of the fuel or from external heat sources. The produced gas leaves the gasifier at a high temperature, and most of this heat is often transferred to the gasification agent added in the top of the bed, resulting in an energy efficiency on level with the ...