Mechanical engineering | Air conditioning, HVAC » Air Conditioning Systems with Gas Absorption Heat Pumps

Source: http://www.doksinet Air conditioning systems with gas absorption heat pumps Natural gas/LPG fired Gambro Dasco S.pA Medolla (Modena), Italy A unique combination considerably different: actually, water-ammonia absorption It’s not easy to find thermal the temperature of the chillers. In this particular case storage systems combined antifreeze (water-glycol) the utilisation of variable phase with absorption chillers. solution can go well below storage systems, it’s even The main reason is the 0 °C, which allows full more attractive than standard incompatibility of lithium compatibility with thermal ice storage. The installation of bromide absorption chillers storage systems. such a system in a small sized and outlet temperatures below The application described office building demonstrates 0 °C. The situation of water- below is a good example of the huge potential for the ammonia absorption chillers is thermal storage coupled with construction

industry. Source: http://www.doksinet Gambro Dasco S.pA, Italy Robur Case History BUILDING DESCRIPTION Floors nr. 2-floor building: ground level and first floor Surface 2512 m2 Heating capacity 291.3 kW Cooling capacity 190.8 kW Absorption with thermal The application The Cooling/Heating System Installed equipment energy storage The HVAC system, installed The HVAC system of the The outdoor thermal station Although uncommon when at the Gambro Dasco S.pA conference rooms combines consists of a gas fired water- applied to absorption factory in the city of Medolla a primary air system with fan ammonia absorption system, refrigeration systems, (Italy), serves a 2-story building, coils. In particular, the primary manufactured by Robur and the use of a thermal storage including offices and air system consists of an air composed with different system can lead to conference rooms. treatment unit combined with models, as follows: considerable energy

savings The 1269 m2 ground floor and ductwork and diffusers, • 1 factory-assembled and gas emission reductions, the 1243 m2 first floor, cover customized for the building; absorption heat pump link as experienced by this medical a combined area of 2512 m2, air treatment unit and fan coils RTAR300-600 CC equipment company. while the average floor height are directly linked (by means (nr. 5 GAHP-AR units); The expansion of the medical is about 3.2 m of a hydronic loop to the • 2 factory-assembled equipment company Gambro The company has outdoor thermal system. absorption chiller links Dasco S.pA, generated the approximately 105 employees: In the offices, heating and RTCF180-00 LB opportunity to install a new 55 of them usually work on cooling is provided by fan coils (nr. 6 ACF60-00 LB units); cooling & heating system, the ground floor, 50 of them connected to the same • 1 factory-assembled link which could guarantee the on the second floor.

hydronic loop. (specifically configured for needed comfort level. Besides the HVAC system, this application) consisting The system was designed an on-demand water heater of 2 absorption chillers with care considering high system coupled with a plate ACF60 HR (with heat efficiency, energy savings and heat exchanger produces hot recovery) coupled with 2 high- low environmental impact. water for sanitary use. efficiency outdoor heating This is the proof of the social The building requires a heating modules (boilers) AY00-119. and environmental corporate capacity of 197 kW and a The outdoor thermal station is responsibility that justifies a cooling capacity of 285 kW. integrated by an ice storage higher initial investment. system, with 2 storage tanks Source: http://www.doksinet Gambro Dasco S.pA, Italy Robur Case History and a heat exchanger. 2 absorption chillers with heat required to recharge the plant produce chilled water at a For the on-demand

production recovery, running by day mode. from 8:00 pm to 8:00 am. temperature of 7 °C while the of hot water for sanitary use, As a result, a gas inlet of The temperature of the ACF60-00 LB chillers an additional plate heat 50.6 kW can generate water/glycol outlet is -7 °C, connected with the storage exchanger was installed. 35.44 kW cooling capacity while inlet temperature is 2 °C. tanks loop send chilled water and 42 kW free heating output Thermal energy is stored in at 5 °C to the heat exchanger. Energy Evaluation simultaneously, covering the storage tanks, containing the Obviously, once the energy The goal of obtaining the needs of hot water for sanitary PCM nodules by means of stored in the tanks has been highest efficiency from this use. In summer, their combined phase changing of the depleted, the tanks are application was obtained by efficiency can reach an nodules’ fluid solidifying at completely cut off and the the installation of gas

fired outstanding rate of a temperature of approximately absorption chillers provide water-ammonia heat pumps approximately 153%, 3 °C and is then released by the entire demand of and chillers manufactured by improving the performance of day to the cooling system thermal energy. Robur. This gas absorption the entire system. through a heat exchanger. The electronic control manages Normally, the cooling demand the entire system automatically. technology gives heating efficiencies up to 140% How the system runs is entirely supplied by thermal A multi-stage thermostat (according to Modena, Italy, In winter, only the GAHP-AR storage tanks, in this case switches on DDCs with this average temperature conditions units and the AY00-119 energy passes throughout priority: first ACF60 HR and provided by UNI 10349) thanks high-efficiency boilers operate, PCM nodules. GAHP-AR units, then the to recovering heat energy from supplying the fan coils, the air When the

demand of cooling ACF60-00 LB units. external air (renewable energy). treatment unit as well as the energy raises, the gas fired In summer, the 2 independent The number of heat pumps plate heat exchanger for the aabsorption chillers switch-on, AY00-119 high efficiency (GAHP-AR) is designed to hot water production. improving the total energy boilers produce on-demand cover the winter heating base The outlet temperature to the capacity. Finally, when the hot sanitary water. load while the boilers hydronic loop is 50 °C, with energy stored in the tanks is However, when the ACF60 HR (AY00-119) cover peak demand. inlet water temperatures at completely depleted, the units become operational, Thanks to an efficient 40 °C, and a combined heating absorption chillers will supply hot water is produced by application, 7927 m3 of natural capacity of 214 kW. the entire air conditioning means of free heat recovery, gas are saved during winter. GAHP-AR gas

absorption heat demand. When air conditioning avoiding unnecessary use of Moreover, in winter the pumps, controlled by a Robur runs on thermal storage only, the boilers and boosting overall application can lead to a Direct Digital Controller (DDC) the system works as follows. efficiency. considerable reduction of with five-step staging logic, Once air conditioning is Conclusion 14 Tons of carbon dioxide. shall have the right of priority switched on, the circulation The utilization of thermal Similarly, further arrangements during winter. pumps shift chilled fluid at 5 °C storage systems with were implemented to allow the The two high-efficiency boilers, from the thermal storage absorption chillers is possible installation of a lower cooling managed by another DDC, system to the heat exchanger. with water-ammonia absorption capacity and provide energy become operational in case of Then, energy passes through refrigeration systems, savings in summer.

temperature or demand peaks, the hydronic loop to the air the only equipment providing First, the installation of two fitting into the system’s treatment unit and fan coils antifreeze solution at thermal storage tanks with a sequence with two-step staging with a temperature of 7 °C. a temperature below 0 °C. capacity of 6500 litres of logic. The control panel When energy stored in the Polyolefin nodules integrating the 2 DDCs is tanks is not adequate to satisfy (manufactured by Cristopia) managed by 2 on-off consent demand, the absorption chillers filled with PCM, Phase Change switches, driven by a 2-step become operational. Material. Thanks to this thermostat. The thermostat A thermostat-driven control arrangement, only 133 kW switches on the heat pumps’ panel switch as on the by day mode and 88 kW DDC first, then the high ACF60 HR units first, the by recharge mode have been efficiency boilers’ DDC. GAHP-AR units second and installed,

allowing savings In summer, the process is finally, in case of high demand, of 64 kW on the installed characterized by a 2-phase the ACF60-00 LB chillers also. capacity, 23% less than operation: recharge by night ACF60 HR and GAHP-AR units necessary. and running by day. directly connected with the air Second, the installation of Six ACF60-00 LB units are conditioning hydronic loop Source: http://www.doksinet Gambro Dasco, Italy Robur Case History Robur S.pA advanced heating and cooling technologies wwwroburcom export@roburit Via Parigi 4/6 24040 Verdellino/Zingonia (Bg) Italy T +39 035 888111 F +39 035 4821334