Investigate the effect of balanced and unbalanced flow in energy recovery system in HVAC system

• Main Author: Lim, Quan Zhong
• Other Authors: Li Hua
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/71198
• Institution: Nanyang Technological University

In recent years, the energy conservation demand attracted much attention due to the depletion of energy source and the impacts of increasing energy consumption on the environment. Heating, Ventilation, and Air Conditioning (HVAC) systems in building contribute to a significant portion of global demand and Energy Recovery Ventilator (ERV) can be employed to overcome the increase of energy consumption without reducing the indoor air quality (IAQ). The purpose of this project is to evaluate the potential cooling energy saving and cost-effectiveness of an ERV. In this study, two separate experiments are carried out. The first experiment is carried out to investigate the effects of factors on the ERV such as: velocity, temperature, and humidity ratio of the airflows. The second experiment focuses on effects of unbalanced flow on the energy saving while other parameters are kept constant. Air temperature and humidity are controlled by a heater and a humidifier to simulate typical outdoor air conditions in Singapore and data are collected through a Data Acquisition (DAQ). Results are collected and discussions on the effects of each factors are explained explicitly. The highest saving of 1,169W for the first experiment is obtained when the outdoor air temperature, difference in humidity ratio and fan velocity are 35°C, 6 g/kg and 2.5 m/s respectively. In the second experiment, sensible, latent and enthalpy efficiency decreased when the exhaust fan velocity is increased. Energy saving is also observed to increase with the difference in fan velocity between supply and exhaust. The highest saving is recorded to be 872 W when the supply fan velocity and exhaust fan velocity are at 2.5 m/s and 3 m/s respectively at outdoor conditions of 30°C, 6 g/kg.