Optimal operation condition division with profit and losses analysis of energy recovery ventilator

•Energy recoveried by ERV should balance its fan power consumption.•Fresh air parameters were classfied into four zones according to profit and losses analysis.•Optimal operation condition can save more energy and decrease operation time.

Energy Recovery Ventilator (ERV) is one of the efficient ways to reduce fresh air load. However, there is a major concern, which energy recovery cannot trade off ERV's fan power consumption, even with causing counteraction to precool (preheat) fresh air in winter (summer). In this study, energy recovery is quantitatively evaluated during cooling season and heating seasons for an office building in Chongqing by employing TRNSYS. Based on the ERV's fan power consumption and energy saving which is converted to chiller's electricity consumption, outdoor fresh air is divided into four zones (zone I, zone II, zone III and zone IV) on a psychometric chart (ID chart). The results show that ERV which only operates in profit zones (zone III and zone IV) can increase electricity saving by 65.23% and reduce operating time by 31.18% than that operating throughout heating and cooling seasons. The proposed operation condition zones method can help identify profit pattern, minimize the energy consumption of ERV and air conditioning system.