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Heat Pumps for Large & Industrial Buildings


  BUILDINGS                    INDUSTRIAL

       Heating, active cooling and hot water for large buildings                                   Process heat and cooling for factories (e.g. chemical, food),

           in commercial, industrial, residential construction                                               power plant engineering and manufacturing processes 

                       and district heating applications                                                                               with high-temperature heat pumps 

Ground Sun are UK distributors and service agents for Austrian-manufactured OCHSNER commercial heat pumps for large amounts of power ranging from 100kW to 1600kW per unit. Both screw and turbo compressors are used and the individual heat pump machines can be installed in series for installations up to 25MW.

OCHSNER can look back on decades of experience in manufacturing, installing and maintaining machines for industrial and commercial building use with temperatures up to 98 degrees. The machines are also used in high-temperature applications up to 130 degrees for power and process heat installations.

The main corporate purpose of OCHSNER heat pump energy technology is to contribute to primary energy savings and reduction of CO2 emissions and thus, reduce operating costs. Even in previously disregarded fields of use, a substantial increase in energy efficiency of the plant technology is achieved with the OCHSNER heat pump product range. Heat pump technology is mature, proven and available today. A perfect example of this is the Zurich city hall which has been heated by water from the River Limmat and a heat pump since 1937.


Screw Compressor Series IWWS, ISWS

  • Capacities - 100kwto 1,600Kw individual machines,placed in series up to 25,000Kw
  • Flow temperatures up to 75°C
  • COP - Typical Coefficient Of Performance Source W10 output 50~COP 4.1 
  • 1-Stage refrigeration circuit 
  • Semi-hermetic compact screw compressor
  • win-shaft rotation displacement machines with asymmetric high-performance profiles
  • Slide switch control, rotation speed control (optional)
  • High operational safety by means of efficient force-fed lubrication
  • Maintenance-free operation
  • Mechanical soft-start using pressure comp when compressor is on
  • Ochsner Electronic Injector technology - used for evaporator and Economizer
  • Highest COP due to precise overheat control
  • Max evaporator use, due to a stable overheating during the complete operational range
  • High security due to full compressor protection (no liquid slugging)
  • OVI-Technology (OCHSNER Vapour Injection)
  • Super-cooling circuit with partial flow vapour injection
  • Increase in heating capacity by increased mass flow
  • Refrigeration Circuit - Tube bundle heat exchanger as evaporator and condenser








  • Screw-type compressor, specially designed for continuous heavy duty at highest temperatures
  • High-performance cooling system with internal circuit  


  • 170 up to 750 kW, TWIN-UNIT up to 1,5 MW
  • In Cascade up to 25 MW 
  • Highest Temperature Heat Pump on the Market







Series High-temperature IWP 95 with Screw Compressor  

  • Capacities - 100kw to 1,600Kw individual machines, placed in series up to 25,000Kw
  • Flow temperatures up to 130°C recently upgraded from 103 °C
  • COP - Typical Coefficient Of Performance Source W10 output 50 ~COP 4.1
  • Multiple solid screw compressors in special high-temperature design
  • Ochsner Electronic Injector technology - used for evaporator and Economizer
  • Highest COP due to precise overheat control
  • Max evaporator use due to stable overheating during the complete operational range
  • High security due to full compressor protection (no liquid slugging)
  • OVI-Technology (OCHSNER Vapour Injection)
  • Super-cooling circuit with partial flow vapour injection
  • Increase in heating capacity by increased mass flow
  • Single-stage refrigerant circuit option:
  • For heat sources from 35-55°C and heat output up to 103°C
  • Use of solid tube heat exchanger for evaporator and condenser
  • Refrigerant: ECO 1 (HFCs / HFC) with low GWP
  • 2-stage refrigerant circuit option:
  • For heat source temperatures from 8-25°C and heat supply temperatures up to 103°C
  • Use of solid tube heat exchanger as evaporator and condenser
  • Plate heat exchanger used as interim heat exchanger, Incombustible safe refrigerant
  • Refrigerant type: 1st stage R134a, 2nd stage ECO 1 (HFCs / HFC), low GWP
  • Special start-up control



                   IKEA BERLIN                          VATTENFALL HAMBURG        CITIGROUP FRANKFURT 

Heating & Cooling Capacity: 3x500 kW                         Heating Capacity: 720kW                                            Heating capacity: 750kW

Source temperature: 10 ° C                                                Source Temperature: 6-16° C                                     Source temperature: 10° C

Flow temperature heating: 40 ° C                                    Flow temperature up to 45° C                                    Flow temperature: 50° C

Heat sources: Sewage, Sprinklers, Air                           Heat source: IT server/Data Rooms                         Heat source: Cooling water return from data centre

Large retail centre13 Storey building,                            50,000m2 floor area                                                      Data Centre build to achieve LEED gold Standard

Commissioning: 2011                                                           Commissioning: 2011                                                   Commissioning: 2008 

Based on decades of experience in process applications OCHSNER designs its high-temperature machines to use safe refrigerant. This represents a true breakthrough in the high-temperature heat pump technology. Comparable temperatures could previously only be achieved with CO2 as the working medium, which, however, meant restrictions on the heat consumption side. The high-temperature working fluid from OCHSNER ÖKO1 (ECO 1), is a non-flammable, safe refrigerant. This eliminates time-consuming safety and maintenance expenses. Due to the low-pressure position and the other thermodynamic properties of ÖKO1 an expensive high-pressure working circuit can be avoided as a high temperature spread on the heat consumption side. Furthermore, ÖKO1 is future-proof from an environmental sense by its low global warming potential GWP. Ochsner run a certified test for every machine on their in-house factory test rigs. They operate a test laboratory especially designed for large machines on which full load tests up to 1000 kW according to EN14511 and EN378, can be performed under field conditions. This creates trust and security for the customer and allows for full (FAT) factory acceptance testing.



Control is performed by a memory-programmable control in combination with a 10 "touch screen with a Human Machine Interface (HMI). The plant is visualized by means of an interactive hydraulic diagram. With pop-up menus, the operating states of the individual system components and compressor are presented. The HMI provides information on the operating state and allows the operation of the heat pump. The Megatronic records all relevant measurements of the system in real time and generates control signals for optimum control of the heat pump. The time profiles of the most important process variables can be displayed as a trend. An alarm management as a basis for possible errors and their prompt correction are also standard. The versatile Megatronic control has among other things a MODBUS®RTU interface for easy connection to process control systems. Continuous recording and storage of all measured values and operating states is possible. The data can be accessed via LAN or Internet. The Megatronic can be easily integrated into a customer's network, so customer adjustments may be carried out remotely.



Screw compressors are a solid design without oscillating parts which makes them most suitable for continuous operation over a long lifetime. This type of compressor offers maximum heating & cooling capacities and numbers with both full-load and part-load operation using Ochsner Vapour Injection (OVI) including a supercooling circuit. The power output can be easily controlled by a slide control to give 50%, 75%, 100% and of rated output slide in steps or continuously. This removes the need for using inverters which have higher losses when compared to variable speed machines. Screw compressors themselves are entirely maintenance free which is why they are chosen for heavy duty applications where continuous operation is required. They offer the highest reliability through efficient forced lubrication with 3-stage integrated oil separator.

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