Centre of Metallurgic Research Azterlan

Heating and cooling for the new office building of Centre of Metallurgic Research (CIM) Azterlan in Durango, Basque Country is provided by a ground-source heat pump / chiller with a nominal heating capacity of 205 kW, connected to a vertical closed-loop geoexchange system consisting of 23 boreholes. Peak load is covered by a roof-top heat pump with a heating capacity of 240 kW. The installation is working succesfully since March 2006. The Seasonal Performance Factor (SPF) for the period December 2006 to May 2008 was 3,6.

General Description
Client nameC.I.M. Azterlan
Application areaIndustry
Building typeOffice building
Year of construction2006
Heat source/sinkBrine/Water
Heat pump typeElectric heat pump
Year of installation2006
PurposeHeating and cooling
Heat source systemBorehole heat exchanger (vertical)
Operation modeBivalent
Contact nameIñigo Arrizabalaga
Contact E-mailiarrizabalaga@eve.es
Contact websitehttp://www.eve.es

Project description

Building, overall energy concept

The new headquarters of CIM Azterlan in Durango, Basque Country is a new building (three storeys plus basement) with a conditioned surface of 3.750 m2 (Photo 1) . Heating and cooling is provided by a 2-pipes distribution system supplying a radiant ceiling and a water/air climatization battery. The heat generation is based upon a GSHP with a nominal heating capacity of 205 kW, connected to a vertical close-loop geoexchange system having a length of 2.780 m, built in 23 boreholes. The GSHP supplies the base load of the building and the main part of the thermal energy demand. The principle sketch of the installation is shown in the figure below.

Design data of the project

- Thermal load of the building:

Heating: 278.551 kWh/year
Cooling: 236.747 kWh/year

- Power consumption of the air-to-water heat pump:

Heating: 112.319 kWh/year
Cooling: 83.069 kWh/year

- Power consumption of GSHP:

Heating: 65.541 kWh/year
Cooling: 53.806 kWh/year

- Geothermal energy output/heat rejection:

Heating: 213.010 kWh/year
Cooling: 290.553 kWh/year

- Final energy reduction GSHP vs. best conventional:

Heating: 46.778 kWh/year
Cooling: 29.263 kWh/year

Heat pump system

Main part of the heat demand is covered by a GSHP/chiller of 205 kW heating capacity (at W7/W45). The heat pump model Dynaciat LG600V was manufactured by Ciatesa. It uses the refrigerant R410a and has two circuits and four scroll compressors. Switching from heating to cooling mode is done by using an external hydraulic circuit based on 2 DN80 four-ways valves (Photo 2).

Operation experiences

The geothermal system is working properly since March 2006. The evaporator outlet temperature is over 5 ºC, using water as heat transfer medium. In cooling operation the condensing temperature is below 35 ºC.

The global performance factor for the period from December 2006 till May 2008 was 3,69 including the energy consumption of the brine pumps and all control devices not included in a conventional system.[Global performance factor = (Thermal energy generation heating+ cooling)/(electrical consumption heating+cooling) along the whole live of the system.]

Main troubles occur in the conventional hydraulic inversion circuit. The two 4-way valves cause up to a 20% of thermal losses, depending on operation conditions and differential pressure between primary and secondary circuits. Several hydraulic troubles are still decreasing the performance of the system that could be improved to more than 4.2. At the moment generation is monitored before and after these valves. The circulation pumps are powered by inverters. There is a full monitoring of thermal energy, generation, electric energy consumption and boreholes production.

Costs, economic efficiency, incentives

- Estimated energy cost savings:

heating: 5.613 Euro/year
cooling: 3.512 Euro/year

- Additional costs against convential air/water heat pump (heating): 176.123,76 Euro

Boreholes (60,6 %)
Civil works & pipes (13.2 %)
Manifold & hydraulic group (9,0 %)
205 kW Chiller ( 10,0 %)
Electric installation, control & monitoring equipment (7,2 %)

- Cost savings (heating):

Not installed 220 kW roof-top heat pump: 40.000 Euro

Subvention as a renewable energy source (RES): 35.200 Euro

Maintenance expenses: 1.500 Euro/year

- Pay-back period (heating): 9,5 years

Regulations, guidelines, benchmarking

Not available.


Characteristic values, performance data
  Design value Measured data
Heating capacity (kW)2205>205
Cooling capacity (kW)3182>182
COP (Heating, appliance)4,0>4,0
EER (Cooling, appliance)4>13,65up to 20
SPF (Heating)53,60
SEER (Cooling)63,82
Annual heat delivery (kWh/year)7278.551153.200
Annual cooling delivery (kWh/year)8236.747120.750
PER (Heating /Cooling)9,101,44/1,53
Annual CO2 emissions (kg CO2/year)25.216

1 Monitoring results covering the period from December 2006 till May 2008.
2 Up to 240 kW
3 Up to 240 kW
4 In passive cooling (geocooling) mode.
5 Including the energy consumption of the brine pumps and all control devices not included in a conventional system. Chiller production up-ward 4-way valves leakage: 4.14
6 Including the energy consumption of the brine pumps and all control devices not included in a conventional system. Chiller production up-ward 4-way valves leakages: 4.26
7 2006/2007/2008 were warm winter years
8 2006/2007/2008 were cool summer years
9 Primary Energy Ratio: Useful heating (and cooling) energy delivered / primary energy input (kWhUE / kWhPE)
10 1,66/1,70 Chiller production

Contacts, Links
Institution/CompanyC.I.M. Azterlan
Responsibility/FunctionOwner, explotation management
Street/PoBoxPol: Montorreta
Contact PersonJ.M. Murua
Phone/Fax+34 94 6215470 / +34 94 6215471
Website (URL)http://www.azterlan.es
Institution/CompanyEVE Basque Board of Energy
Responsibility/FunctionDesign, construction and funding
Street/PoBoxAlda. Urquijo, 36-1º
Contact PersonIñigo Arrizabalaga
Phone/Fax+34 9440 35600 / +34 9440 35699
Website (URL)http://www.eve.es

Supported by

Seventh Research Framework Programme
Collaborative project
No TREN/FP7EN/218895