Study on the energy efficient potential of natural ventilation for residential building in Guangzhou

Natural ventilation is the most effective to reduce the energy consumption of air conditioning for residential building in Guangzhou with subtropical climate. But the effect of natural ventilation on energy saving couldn't be evaluated quantitatively at present. In this paper, an analysis method to evaluate quantitatively the energy saving potential of natural ventilation was proposed. Firstly, the base room temperature with different air change times of natural ventilation was simulated. The number of hours in that the indoor air temperature could meet thermal comfort requirement only by natural ventilation in occupied period was calculated. Secondly, the cooling loads of building were simulated when the air conditioning intermittently run. The air conditioning system run when the base room temperature is higher than 29°C with natural ventilation even the air change times could reach 120h
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. Then cooling loads reduced rate was calculated by comparing the result to the baseline, which is the cooling loads of building with the air change time 1h
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. Based on the results of calculation, it was found that air change times 80h
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could be as a requirement to realize the largest energy saving potential of natural ventilation. The energy saving effect of natural ventilation is the most obvious while air change time is not less than 20h
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. The energy saving potential of natural ventilation in general structure in 1980s is smaller than that in the building with the new structure according to the energy efficiency standard of China.