Heating and ventilation flow pulsation for energy saving and indoor air quality

Heating and ventilation of buildings is the second largest energy consumption after transportation and significantly contribute to the CO2 emission. The current heating and ventilation systems operate at constant flow strategy with On/Off control which leads to higher energy consumption. Therefore there is a need for alternative ways of operating the heating and ventilation systems so that energy can be saved without compromising the occupant's wellbeing including indoor CO2 and humidity levels. Flow pulsation has been applied for various applications to enhance heat transfer for heating and cooling appliances. This work mathematically investigates the effect of radiator hot water and inlet air ventilation pulsation for a living room in a 4 bedroom house with 5 occupants to improve the energy consumption and indoor air quality (IAQ) using demand based embedded control system in MatLab/Simulink software. The developed model is targeting to control the indoor air quality and thermal indoor comfort of occupants, including temperature of 20± 2 (°C), CO2 level of 1000 ± 100 (PPM) and relative humidity of 50± 10 (%). Flow pulsation for both heating and ventilation was applied at flow frequency of 0.016 (Hz) with the amplitudes of the water and air flow pulsation vary depending on heated space environment. Results showed that pulsating the flow of hot water through the panel radiators of the central heating system can achieve an average of 20(%) energy saving compared to the constant flow currently use. Also, using pulsating air flow to the heated space (for ventilation purpose) can achieve energy saving of 34.5% in the fan power consumption of the ventilation system by keeping the level indoor CO2 concentration and relative humidity at an acceptable level. The significant saving achieved by flow pulsation indicates the potential of using this approach to reduce energy consumption and improve the indoor air quality.