Presentation Title Date xx, 2004

1
EDRASIS HEADQUARTERS Vassilios Ramoutsakis,
EDRASIS C. Psalidas SA Angelos Goumas, Dimitrios
Mendrinos, CRES
Building and Use
Heating Cooling System
Heat Pump

• The heat pump used at the EDRASIS demonstration
  site is a prototype developed by OCHSNER
  Wärmepumpen specifically for the Ground-Med
  project.
• It is an improved version of OCHSNER WP model
  OWWP56S. The machine uses one compressor and
  R407c as refrigerant.
• The improvement focus was on COP optimization.
  For this purpose tasks carried out by the heat
  pump manufacturer included
• calculation and optimization of heat exchangers
  as evaporator and condenser,
• design of optimum refrigerant distributor for
  evaporator with the goal of optimizing
  refrigerant-impingement for increasing the
  evaporation pressure on the refrigerant side,
• theoretical calculation of the amount of
  refrigerant for all three refrigeration circuits,
• interpretation of refrigerant lines
• definition and dimensioning of heat pump
  components.
• The result was a heat pump prototype of superior
  efficiency with 15 improved COP over the
  marketed machine.
• Heat pump parameters at 10/6//30/35ºC are
• Heating capacity 57,75 kW
• Power consumption 9,76 kW
• COP
  5,92
• Improvement 15

Heating
Building location

photo 2
BHE field
Cooling (Active)
photo 3
Building plan
EDRASIS C. Psalidas SA is a public construction
company located near the Athens airport. It hosts
the corresponding Ground-Med demo site, in order
to cover base load heating and cooling needs of
its headquarters, which comprise the main hall,
offices, conference rooms and lobbies. Total
area of the building 2860
m2 Heating power demand 249
kW Cooling power demand 273 kW
Cooling (Passive)
GROUND SOURCE HEAT PUMP SUPPLIER
OCHNER MODEL OWWP 56 i DIMENSIONS
695mm x 585mm x 1850mm WEIGHT 238 kg HEATING
CAPACITY 55 kW (40/35C in heating
circuit, 11/7C in BHE) COOLING CAPACITY 48 kW
(6/10C in cooling circuit, 30/35C in
BHE) REFRIGERANT R407C COMPRESSOR POWER 9,75
kWe WATER PUMP WILO IPL32/160-1.1/2 PUM
P ELECTRICAL POWER 1,1KW NOMINAL WATER SUPPLY
2,64 l/s
Borehole Heat Exchanger
Heating Cooling System
For heating operation the GSHP supplies only the
fan coil units on a continuous basis. The total
heating load of the fan coils is approximately 65
KW. Whenever the demand is more than 55KW, the
existing boiler will be automatically connected
by the BMS system. For cooling operation the
GSHP works on a continuous basis connected to the
entire system (AHUs and FCUs) up to the its
maximum power. When the system requires more than
this, the existing chiller is connected to the
system, automatically by the BMS.
12 Borehole HEXs, PE 100/16 bar, closed loop,
Double U, Ø 32 mm, water as working
fluid. Grouting Above water level
bentonitic cement Below water level
graded sand or gravel Borehole Specifications
Depth 110 m Diameter 165 mm Spacing 6
m Soil Parameters General soil profile clay
and limestone Water level
30 m Thermal conductivity 2,016
W/mK Volumetric heat capacity 2,3 kJ/Km³