Performance investigation of a fresh air pre-handling system integrated with pipe-embedded envelopes by utilizing shallowgeothermal energy.

Traditionally, shallow geothermal energy is utilized by ground source heat pump. Actually, the temperature of shallow geothermal energy is much suitable for the cooling/heating of the building envelope and fresh air in most of time. To utilize shallow geothermal energy more efficiently, an integrated system combined pipe-embedded walls, pipe-embedded windows, and fresh air prehandling system is proposed based on the temperature comparison among the indoor air, envelopes, fresh air and the undisturbed soil. The simulation model of the integrated system is developed on the platform of TRNSYS. The free-running temperature of the integrated system applied in an office building in Shanghai is investigated. The results show that the free-running temperature of the integrated system is always higher than 15 °C throughout the year, the free-running temperature that higher than 30 °C accounts for a fewer ratio and the non-air conditioning period extends approximately 20% compared with the conventional GSHP system.