University of Almería

The CIESOL building is one of the five C-DdI (research demonstration containers) of the Strategic Singular Project on Bioclimatic Architecture and Solar Cooling (PSE-ARFRISOL).

The CIESOL building at the University of Almería has an advanced, environmentally friendly energy-saving system based on solar thermal collection, used to produce hot water and air-condition the building.

Project basis

The main aim of the project was to show that it is possible to save 80 % to 90 % of conventional energy through the correct application of active and passive solar technologies, adapting the building’s design to its surroundings and climate. With this aim, a solar cooling and heating system was installed in the CIESOL building in 2006. The system essentially consists of a field of flat-plate solar collectors, a YAZAKI absorption chiller, a cooling tower, two thermal storage tanks and a back-up system.

The installation meets the CIESOL building’s cooling and heating demand and serves as a test bench for research.

Solar thermal field

The solar field is laid out on the building’s sloping, south-facing roof. The collectors are set at an angle of 30º to favour heat collection during the summer months, when the need for heat input is greatest.

The solar field consists of a total of 80 collectors, with a total collector area of 160 m2, arranged in 10 rows of 8 collectors each.

The installation has two thermal energy storage tanks of 5,000 litres each, which store the energy collected but not used immediately. There is also a propane-fired back-up boiler to maintain the service when solar energy runs out.

Absorption chiller

The plant installed is a YAZAKI WFC SC20 single-effect absorption chiller with a nominal cooling capacity of 70.2 kW, driven by hot water heated by solar radiation, which powers its absorption refrigeration cycle using a water and lithium bromide solution that is completely harmless to the environment.

The inlet temperature range to the generator of the YAZAKI absorption chiller is between 70 and 88 ºC.

Using this free thermal energy also avoids the CO₂ emissions inherent in consuming any other kind. The plant’s job is to chill the water in the closed circuit to 7 ºC to air-condition the research centre through fan coil terminal units.

Competitive advantages

• The absorption cycle has almost no moving parts, so wear and maintenance are very low.
• For the same reason, its performance stays constant over its long service life.
• In many cases it provides cooling without having to increase the contracted electrical capacity, and even avoids the need for a transformer substation.
• Using free or primary energy considerably reduces running costs.
• In all cases, the absorption cycle is completely environmentally friendly, both in the fluids and in the energy it uses.
• It helps reduce national dependence on imported hydrocarbons.