HeaMo – Heat in Motion
Effectively redistributing energy for simultaneous supply of heating and cooling
Everyone speaks about energy efficiency -- not only the lawmakers, but also from our demanding customers. Especially in building technology, sustainability with respect to energy-reduced operation has become essential. Investors, planners, and architects accordingly demand resource-conserving energy management for building services.
Buildings of all kinds account for 40 % of total world energy consumption, and are responsible for 21 % of global greenhouse emissions. There is great potential for energy savings here – both from ecological as well as economical standpoints. Simultaneous cooling and heating is no longer a rarity in advanced building services. Some reasons for this can be found in the reduction of heat-transmission losses, a high share of inner cooling loads, and also in the continually growing share of glass façade glazing in modern architecture. Certain types of buildings demand the simultaneous provision of heating and cooling over long periods.These include buildings with north and south orientation, facilities with requirements for all-year cooling of electronic switching and communications centers, and applications with great demand for warm water for sanitary facilities.The same especially applies to the spring and autumn of each year in hotels. The same particularly applies during the spring and autumn periods for hotels:
Simultaneous heating and cooling in individual rooms is often indispensable because of the individual temperature sensitivity of the guests during such periods.
Today it is no rarity for systems to provide chilled water for cooling requirements and systems to supply warm water, to be operated in parallel. However, energy optimization potentials then remain unused.
The HeaMo unit (HeaMo stands for Heat in Motion) uses the heat arising from refrigeration to supply the warm water requirements of the building. The output and temperatures of the chilled and warm water systems can be individually controlled depending on the cooling and heating loads prevailing in a building. The greatest possible effectiveness is achieved when simultaneously cooling and heating energy must be provided in equilibrium. This assures that no cooling or heating energy must be wastefully emitted to the environment. But also the purely chilled- or warm-water operation is possible with HeaMo without difficulty.
Up to now, chilled water for cooling requirements and systems to supply warm water are operated in parallel. But this left energy optimization potential unused.
The HeaMo unit uses the heat arising from refrigeration to supply the warm water requirements of the building. The greatest possible effectiveness is achieved when simultaneously cooling and heating energy must be provided in equilibrium.
Operating modes
One application – various operational modes
100 % cooling demand – 100 % heating demand
The HeaMo unit operates under an optimal energetic mode. The energy removed from the chilled water is added to the warm water. This way the unit can supply the building with chilled water for cooling and warm water for various heating purposes, without energy waste. Energy is re-distributed throughout the building wherever it is momentarily needed . The operation of this unit corresponds to that of a water-cooled chiller – whereby the output of the hot-water side can also be individually controlled, and not only the chilled-water side. The air-cooled third heat exchanger is not in operation.
100 % cooling demand – 50 % heating demand
All compressors are in operation, in order to meet cooling demand. Both of the refrigerant cycles remove energy from the chilled-water heat exchanger, which cools the chilled water. Since, however, only 50 % of the heating capacity is required, only one refrigerant cycle to the hot-water heat exchanger is in operation. The second refrigerant cycle uses the air-cooled Cu/AI heat exchanger as a condenser to give off surplus heat to the outdoor air.
100 % cooling demand – 0 % heating demand
The system functions as a chiller. Energy is removed from the cold-water heat exchanger and is given off to the outside air via the air-cooled Cu-Al heat exchanger. The compressors switch on and off according to the cooling demand, in order to assure constant chilled-water temperatures. If warm water becomes necessary again during this mode, one refrigerant cycle switches from the air-cooled heat exchanger to the hot-water heat exchanger.
0 % cooling demand – 100 % heating demand
The HeaMo unit uses the outdoor air as free energy source, in order to return the energy removed from the air to the building in the form of warm water. During this operational mode, refrigerant is not pumped to the chilled-water heat exchanger. If changes in the heating load occur, compressors will switch on and off accordingly. If the demand for cold water increases, one cold-water cycle will switch over from the air cooled heat exchanger (which is used as an evaporator in this mode) to the cold-water heat exchanger.
1 Refrigeration circuit 1 with compressor 1 + 2
2 Refrigeration circuit 2 with compressor 3 + 4
3 Condenser
4 Auxiliary air heat exchanger
5 Evaporator
The operating mode of the HeaMo AIR shown here is analogous to the HeaMo GEO manner of operation. The HeaMo GEO unit, however, uses geothermal energy sources for pure cold- or hot-water operation, and in cases of asymmetrical load distribution.