boiler repairs Harrow Water heating
Circulating hot water can be used for central heating. Sometimes these systems are called hydronic heating systems.15
Common components of a central heating system using water-circulation include:
A supply of fuel, electric power or district heating supply lines
A Boiler (or a heat exchanger for district heating) which heats water in the system
Pump to circulate the water
Radiators which are wall-mounted panels through which the heated water passes in order to release heat into rooms.
The circulating water systems use a closed loop; the same water is heated and then reheated. A sealed system provides a form of central heating in which the water used for heating circulates independently of the building's normal water supply.
An expansion tank contains compressed gas, separated from the sealed-system water by a diaphragm. This allows for normal variations of pressure in the system. A safety valve allows water to escape from the system when pressure becomes too high, and a valve can open to replenish water from the normal water supply if the pressure drops too low. Sealed systems offer an alternative to open-vent systems, in which steam can escape from the system, and gets replaced from the building's water supply via a feed and central storage system.
Heating systems in the United Kingdom and in other parts of Europe commonly combine the needs of space heating with domestic hot-water heating. These systems occur less commonly in the USA. In this case, the heated water in a sealed system flows through a heat exchanger in a hot-water tank or hot-water cylinder where it heats water from the regular potable water supply for use at hot-water taps or appliances such as washing machines or dishwashers.
Źródło: https://en.wikipedia.org/wiki/Central_heating
Historical fact - central heating
The ancient Greeks originally developed central heating. The Temple of Ephesus was heated by Flues planted in the ground and circulating the heat which was generated by fire. Some buildings in the Roman Empire used central heating systems, conducting air heated by furnaces through empty spaces under the floors and out of pipes in the walls?a system known as a hypocaust.23
The Roman hypocaust continued to be used on a smaller scale during late Antiquity and by the Umayyad caliphate, while later Muslim builders employed a simpler system of underfloor pipes.4
After the collapse of the Roman Empire, overwhelmingly across Europe, heating reverted to more primitive fireplaces for almost a thousand years.
In the early medieval Alpine upland, a simpler central heating system where heat travelled through underfloor channels from the furnace room replaced the Roman hypocaust at some places. In Reichenau Abbey a network of interconnected underfloor channels heated the 300 m? large assembly room of the monks during the winter months. The degree of efficiency of the system has been calculated at 90%.5
In the 13th century, the Cistercian monks revived central heating in Christian Europe using river diversions combined with indoor wood-fired furnaces. The well-preserved Royal Monastery of Our Lady of the Wheel (founded 1202) on the Ebro River in the Aragon region of Spain provides an excellent example of such an application.
Źródło: https://en.wikipedia.org/wiki/Central_heating
Something about bathtub
A bathtub, bath or tub (informal) is a large container for holding water in which a person may bathe. Most modern bathtubs are made of acrylic or fiberglass, but alternatives are available in enamel on steel or cast iron; occasionally, waterproof finished wood. A bathtub is usually placed in a bathroom either as a stand-alone fixture or in conjunction with a shower.
Modern bathtubs have overflow and waste drains and may have taps mounted on them. They are usually built-in, but may be free-standing or sometimes sunken. Until recently, most bathtubs were roughly rectangular in shape but with the advent of acrylic thermoformed baths, more shapes are becoming available. Bathtubs are commonly white in colour although many other colours can be found. The process for enamelling cast iron bathtubs was invented by the Scottish-born American David Dunbar Buick.
Two main styles of bathtub are common:
Western style bathtubs in which the bather lies down. These baths are typically shallow and long.
Eastern style bathtubs in which the bather sits up. These are known as ofuro in Japan and are typically short and deep.
Źródło: https://en.wikipedia.org/wiki/Bathtub