Warm House in All Weathers
A necessity to raise energy efficiency in the Russian housing and municipal sector (firstly in the field of heat supply) doesn’t give rise to doubt. A reform continues some years but both professionals of the sector and consumers of heat energy don’t have clear idea about the efficiency of different energy saving measures and their realization sequence. Many consider that it is enough to apply, for example, an automation of heat units in residential houses. Consumers very often believe that the heat supply is a synonym of heat insulation; and the heat system modernization is only an installation of general house counter.
A general state of heat supply systems in majority of residential houses built till 2000 year in Russia needs a reconstruction as technologies of head supply, distribution and recording applied before don’t meet requirements of the modern legislation on energy saving. It is impossible to save the heat until the consumption becomes regulated. Therefore, it is necessary to apply to basic principles for energy saving on the level of the central heating system before modernization. A heat consumption control is realized on three levels: heat input, balancing in pipes and direct adjustment on heat equipment.
HEAT INPUT OF BUIDING
The first level is a regulation of total heat volume consumed by a building directly in a heat unit. Elevatortype heat units applied before didn’t provide the opportunity and so were recognized ineffective. Edition of SNiP “Heat, ventilation and conditioning” which is in force doesn’t suppose an application of similar schemes (including “regulated electronic elevators” or “economizers”) in block of flats.
Today’s standard solution is an automatic heat unit: individual automatic heat point or automatic control unit (heat point with pumping addition and without heat exchanger for a system with dependent connection). A supply of heat-transfer agent is regulated directly at heat input and controlled by automation; the heat supply regime is controlled depending on inner supply and fluctuations of outside temperatures (weather compensation).
As a practical experience demonstrates, an automation of the heat unit gives averaged 15-25% of saving if heat isolation norms for envelopes are met.
HEATING SYSTEM PIPES
A hydraulic resistance of the system is increasing when moves from the heating input. As result, there is an overheating in some pipes and underheating in other pipes; and it happens all at once. Corner rooms which are the last in the chain often don’t receive enough heat. But if to regulate a heat consumption in accordance with them, the overheating will intensify more. Automatic balancing valves which justify a consumption of heattransfer agent in pipes help to avoid it. - It is another obligatory condition for the qualitative modernization of the heating system.
Developments appeared in recent years permitted to obtain other qualitative level for the efficiency of balancing and approximate single- pipe systems to double-pipe systems by indexes of energy efficiency. Specialists of the company “Danfoss” developed an adjusting thermoelement QT for automatic balancing valves AB-QM. The device permits to adjust automatic consumption in pipe depending on temperature changes of the reverse heat-transfer agent. Thereby, a general balancing valve serves a double function, permits to increase an efficiency of balancing due to adjusting of consumption in dependence on temperature changes of the reverse heat-transfer agent. But the thermoelement QT can be applied only with valves AB-QM made by “Danfoss”. An application of the additional device permits to approximate single-pipe systems to double-pipe systems in heat saving due to the energy efficiency balancing; and the heat saving due to the balancing is up to 5-10%. Before coming in Russia, the technology was successfully applied in foreign.
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Materials provided by the company “Danfoss”