ground cooling

The present study reports the results of a 12-month-long monitoring campaign of an earth-to-air horizontal heat exchanger (EAHX) system in a school complex in Imola, Italy. With more than 2 km of buried pipes, it represents one of the biggest Italian applications of this technology. Considerable differences between inlet and outlet air temperature have been noticed both in winter and in summer. Air temperature and relative humidity have been represented over a psychrometric chart while the energy performance of the system was analysed based on data of sensible heat exchange.

Passive cooling in the built environment is now reaching is phase of maturity.  Passive cooling is achieved by the use of techniques for solar and heat control, heat amortization and heat dissipation. Modulation of heat gain deals with the thermal storage capacity of the building structure, while heat dissipation techniques deal with the potential for disposal of excess heat of the building to an environmental sink of lower temperature, like the ground, water, and ambient air or sky.

This study presents some results from a monitoring project with night ventilation and earthto- air heat exchanger. Both techniques refer to air-based low-energy cooling. As these technologies are limited to specific boundary conditions (e.g. moderate summer climate, low temperatures during night, or low ground temperatures, respectively), water-based low energy cooling may be preferred in many projects. A comparison of the night-ventilated building with a ground-cooled building shows major differences in both concepts.