Home heating systems. Home heating systems Egipt

No matter how hard we try to snug building, problem of insufficiently high or excessively high temperature in it during cold time of year is connected basically with of heating devices.
Basically we deal with radiators of water heating connected to central system of heating for one house or a group of houses. Radiators can be steel and iron, can be put near wall or built into it. principle of work of a radiator is limited to transfer of thermal energy of heating body (heat-carrier) through its case to environment (air, wall), for premises it is water or mineral oil. In industrial premises water pairs can be used as heat-carrier. It is obvious, that bigger area of surface of case of radiator, contacting with environment is, more warmth it will transfer. "To compress" working area of radiator in a more compact form, it is made in form of jointed tubular or laminar parts, heat-carrier circulates inside of them in special channels. more such parts it has - thermal efficiency gets bigger and a lot of air is involved in circulating heat exchange around radiator, as a result, it provides equal heating of all air of premise. When according to operating conditions large surface of thermal efficiency is not required, radiator is made in form of one smooth fin or a pipe.

Thermal efficiency of a radiator depends not only on volume of circulating air around it, but also on efficiency of natural air circulation around it, which exists because of heat exchange between warm and cold air masses.
Warm air rises from radiator or from heated wall, then it is cooled near ceiling, as it falls down, walls of room, objects in it, and at last, floor make air cooler; and it is directed again to radiator, filling tenuous zone in bottom part of radiator. main work peculiarity of a radiator is that 80% of its work is heat production (that is why it is called like that, its Latin base - Radio - means radiate) and 20% of its work is recirculation of air. While putting decorative covers and furnishing building it is important to remember that any barriers for heat or obstacles for air circulation make degree of efficiency of radiator smaller.

It is clear that no furniture should be put in front of radiator, if you want it to work with maximum efficiency.
best way to put radiator in room is to place it near cold (outer wall) wall and under window, if there is one in this wall. The warm air from radiator heats cold wall and window and impedes cold air from getting into room. zone near entrance door is another part of room, which needs a warm barrier (usually in a smaller degree). You should keep it in mind that if for some reason there are not enough radiators of central heating system, you will need extra heaters to have normal temperature in room.

The temperature of working surface of heating device (radiator) must not be higher than 70 degrees.
Otherwise dust in circulating air is burnt, which makes air drier and causes an unpleasant smell of heated radiator. By way, a lower temperature of radiator can cause dry air too, so when it is not possible to lower temperature because there is no an adjuster or because it is not practical, air in room must be humidified with help of special devices and equipment, which will be specified later.

Dust radiator in due time because dust makes level of heat capacity lower and creates an unpleasant smell in room. Wall or open radiators heat air in room better than closed ones, and definitely better than those which are built into wall. Form point of view of esthetic people want to hide radiators with help of decorative covers, curtains or furniture, but then it is necessary to observe following rules to make resulting heat losses minimal.

Autonomous heaters - heating stoves, fireplaces, electroradiators, electroheaters, electric blowers, conditioners have bigger degree of efficiency than central heating system because they are connected with source of energy; but they are much more expensive in exploitation, so it is recommended to use them only if there is no central heating or as n additional source of heat.

The convenient in use are radiators working on electricity - electrical radiators. They can be classified as radiators heating air (electroheaters and electric blowers), and radiators (electroradiators) which pass energy from heating device to coolant (mineral oil) and then through radiator to air.

The most fast-acting electroheaters are electric blowers. Their work is based on air circulation around heating device with help of a ventilator. That is why their main disadvantages are noise from working ventilator, and quite a big amount of used electricity which is necessary in this case not only for heat production but also for ventilator itself.

Electroheaters, unlike electric blowers, almost completely work as heat radiators recirculation of air in electroheaters is not big, that is for greater heating capacity of device directed or dissipative reflectors of heat emission are used in form of metal screens of different shapes.

electroheaters exploitation rules

There are functional varieties of electroheaters: electrical fireplaces, which have similar forms to traditional fireplaces and great capacity of heat emission. They create an illusion of open fire, unconsciously we always strain after it, and if placed sensibly can make room cozy, but they use a lot of energy and space.

Household electric blowers and electroheaters are handy in use because they are compact, but amount of heated air is not big as surface of heat emission is small, and their heating capacity is of immediate effect. That is why electroradiators are considered to be more effective as their surface of heat emission is considerably bigger and they are able to store heat in energy carrier - oil. Their work is similar to work of radiators of central heating system, but they have an advantage: they have a device for automatic regulation of temperature of oil (thermoregulator).

There are two kinds of thermoragulators:

Indicators of air temperature are put on a cord in some heaters, and that allows thermoregulator to react to changes in air temperature at some distance from source of heat. adjustment of work regime of such radiators is not supposed to be more-less, but it is performed according to scale of needed temperature in room. It is easier to use such kinds of heaters so it is better to give preference to them. For instance, if you want temperature in room to be 20 degrees all time, you adjust thermoregulator on mark 20 degrees; every time when air temperature reaches that mark, thermoregulator switches off heater, when temperature gets lower than 20 degrees it will switch it on.

The size of room and needed power of heater are in direct dependence. bigger size of room which must be heated, more powerful heater will be needed.