Research on the Energy Saving Performance of the Enthalpy Recovery Ventilator in Chinese Residential Buildings

In order to fulfill the indoor comfort and health requirements, people need to supply a large amount of outdoor fresh air into the indoor environment. In the past, because of the poor airtight performance of the residential buildings in China, there is usually no mechanical ventilator installed, almost all of the outdoor air infiltrates from the leaks through the windows and doors. Recently, in order to improve the energy saving performance, the windows and doors of the residential buildings become more and more airtight so that the outdoor air can’t infiltrate into the rooms easily, but it results in the worse and worse indoor air quality. People need supply enough outdoor fresh air into the rooms without increasing the energy consumption greatly. The installation of the enthalpy recovery ventilator (ERV) is an effective method. It can transfer heat and moisture from the exhaust air into the outdoor fresh air to save energy. Nowadays, ERV has been widely used in the commercial and industry buildings, and started in the residential buildings in China. But ERV is not always energy saving in anywhere and anytime. Its energy saving performance depends on a lot of factors, such as the outdoor environmental condition, the enthalpy effectiveness of the enthalpy recovery medium, the Coefficient of Performance (COP) of the air condition system and so on. Based on the weather data, this paper calculates the hourly energy saving performance of ERV for residential buildings that are hypothetically located in five Chinese representative cities of five different climate zones in summer. It gives the definition of the cooling ventilation season and studies the influence factors related to the energy saving performance of ERV.