The performance of a passive heating system was evaluated as part of design works for the project of an office building. The passive heating system incorporates an array of buried pipes together with a solar chimney. The solar chimney collects solar energy, heating fresh air and pulling it from an array of buried pipes. The array of buried pipes was used as an open loop earth-to-air heat exchanger and air circulation inside pipes is due to the action of the solar chimney. We studied the heating fractions due to the solar chimney and to the buried pipes. The application of this system to the acclimatization of an office building was evaluated. A model was developed on this purpose, which allows foreseeing the temperature and relative humidity of the air in the building. The performance of the passive heating system was evaluated based on the energy absorbed by the ventilation air.