GROUND-MED PROJECT COIMBRA DEMO-SITE André Quintino Duarte Coimbra, 23 February 2012

Demonstration Building Total area: 3250m 2 Four floors Two public services installed Offices, laboratories, conference room Capacity for 250 permanent workers + 72 temporary people in a conference room Located close to a river “Fábrica dos Mirandas”

Demonstration Building

The heated /cooled spaces are located in level 3 of the building (last floor). 22 rooms (offices) Approximately space conditioned area 600 m 2

Demonstration Building

Simplified schematics of the hydraulic installation 75 mm Diameter PPR Pipes in the main sections

Borehole Heat Exchanger DOUBLE U TUBE Borehole diameter (d)160mm Pipe internal diameter (D2)32mm Pipe external diameter (D1)35mm Shank spacing (s)56mm Seven vertical boreholes 125 m deep 5x5 m rectangular grid grout material is graded sand (pea size mm )

Geological Profile Alluvium Limestone / Sand / Silt Clay Loam Earthworks High Groundwater flow Freatic Groundwater level – 5 metres

Location of the Boreholes

Heat Pump Reversibility is done on the water side in order to always be in counter current on the heat exchangers. This is achieved by 3-way motorized valves

Piping System

Heat Pump Test Results Conditions Cooling mode EvaporatorCondenser Cooling capacity EER Eurovent Class A InletOutletInletOutlet EUROVENT12°C7°C30°C35°C56 kW5.05>= 5.05 Coimbra demo site 15°C10°C25°C30°C63.5 kW6.19n.a. Conditions Heating mode EvaporatorCondenser Heating capacity COP Eurovent Class A InletOutletInletOutlet EUROVENT10°C*40°C45°C61 kW4.58>= 4.45 Coimbra demo site 15°C**35°C40°C70.4 kW5.65n.a. The performance of the heat pump prototype was tested at the CIAT Culoz research center. Heating Capacity – 70.4 kW Cooling Capacity – 63.5 kW

Circulation Pumps High efficiency permanent magnet motor pump supplied by Grundfos, with variable speed control.

FanCoil Units The Fan Coil units were supplied by CIAT. They are COADIS 2 fancoil units models 235/22 and 235/33. A total of 33 units were installed – 23 units of model 235/22 and 10 units of model 235/33. These fancoil units are equipped with high efficiency impellers and high efficiency permanent magnet motors.

FanCoil Units

Each fan coil can be individually regulated by means of a thermostat. Comfort temperature can be selected by the user by means of a wall mounted control and fan speed is controlled automatically by means of a 0-10V control signal. The fancoils had to be retrofited with an electronic fan speed limiter, because of the noise generated was unacceptable by the users.

Location of the fancoil units

Thermal Storage The thermal storage tank is to be located in a room adjacent to the machinery room. It is planned to have a volume of 3.5m 3 (40% water + 60% PCM). Research is being conducted with the support of the Fluids Thermal Transfer Group of the Department of Mechanical Engineering on the best design of the tank to ensure optimal heat transfer and to ensure that the storage maximum capacity of the PCM modules is used. It was found that the most suitable material would be the S46 salt hydrate from PCM products Ltd (UK)

Preliminary test results

COP = 6,03

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