'Pompeu Fabra' Library in Mataró, Spain

Description of the application

The Pompeu Fabra Library of Mataró is a building that was designed to integrate a photovoltaic and a solar thermal system in the own structure in order to produce electricity and heating, keeping the requirements of a public library. The optimal equilibrium between energy, comfort, natural lighting, aesthetical appearance and economical resources was applied in the conception of that building.

General description of the system

Between 2000 and 2002 a new project in the framework of JOULE III, called AIRCOOL, was carried out to develop a desiccant cooling unit integrated with the photovoltaic modules and a new solar air collectors field, with air as the only heating and cooling fluid, to provide air-conditioning to the audiovisual-children area. The responsible ones of this project were HfT Stuttgart, TFM S.A., Grammer, Loughborough University, Siegle+Epple and Sauter Ibérica.
This new system was designed to improve the global energy efficiency of the building, as well as comfort in the west side area, taking profit of the existing solar equipment.
The capacity of the new cooling unit is 55 kW with a solar air collectors field of 105 m², south oriented and with a tilt angle of 20º. The total airflow rate is 12,000 m³/h. A compression cooling unit and a gas boiler are the back-up systems to support the solar cooling and heating production.

Central air-conditioning unit


open cycle (DEC)

Nominal air volume flow rate

12,000 m3/h

Minimum air volume flow rate

6,000 m3/h

Desiccant cooling system type

solid desiccant

Desiccant type

silica gel

Cooling capacity

81 kW

Brand of desiccant unit

Siegle+Epple (ATU), Seibu Giken (wheel)

Solar thermal

Collector type

air collector

Brand of collector


Collector area

88 m2 aperture

Tilt angle, orientation

20°, 5° west

Collector fluid


Typical operation temperature

65 °C driving temperature for chiller operation


Heat storage


Cold storage


Auxiliary heating support


Use of auxiliary heating system


Auxiliary chiller


- type

el. compression chiller

- capacity

246 kWcold

System performance

About environmental impact it can be noticed that noise problems detected in start-up period has been avoided. The technology guarantees a high primary energy savings using solar energy. The main environmental problem is the high water consumption. Humidifiers must be kept very clean to minimize this problem. Moreover, some proposals to recycle the water from humidifier should be considered by the owner. Water consumption is not registered by the system but a comparison in the bills before and after the installation of the system shows a increasing of 217 %.
Desiccant and evaporative cooling system with vapour compression back up for cooling is a technology that works properly in a humid and hot climate as the Mediterranean coast premises.

System reliability and overall success of the installation

The system is working properly, the indoor comfort conditions are better than the ones obtained with the previous installation, due to the fact that air cooling capacity has been increased and the load has been reduced using shading devices over west windows. The users are satisfied with the system. The users do not notice any incidence about uncomfortable air conditions during 2004 year operation.
Besides these improvements on the building air conditioning system, this installation consists on a demonstration of an environmentally friendly technology.

General information

Type of building  library
Location  Mataró, Catalonia, Spain
In operation since  July 2002
System operated by  the owner
Air-conditioned area  471 m2
Capacity  81 kW


Dessicant machine
Caption 1
Collector area
Dessicant machine
Scheme of the system
Collector area

Clicking an image opens the gallery view.

Specific information

Further specific information about the system are included in the filled in technical questionnaire.


183 K


For more information on the project please feel free to contact:

Marie Proville