Energy savings in the Heating Ventilation and Air Conditioning (HVAC) systems have attained significant awareness recently not only because of its high energy consumption but also due to our nation’s objective of reducing global warming. Hence, smart and power-efficient HVAC systems have substantial requirement.

The conventional HVAC system is not aware of the heat load and occupancy of the building since each of its equipment works independently from each other. Hence, the system is unable to control certain parameters appropriatelyeventually resulting in imbalanced cold air distribution, cooling of unoccupied zones, excessive cooling at certain location and inability to control different HVAC machines dynamically. Since the conventional system cools the unoccupied zones, there is more energy spent than it is supposed to. Another impediment is the lack of visibility of its equipment due to the predicament of integration of subsystems. The existing solution to these impediments is complicated and pricey. But the Green HVAC system proposed as part of this thesis, has a plug and play and economical solution to all these concerns encountered by the conventional system.

The principal component of Green HVAC system is the Variable Air Volume (VAV) box which assists in providing customized temperature control in each zone and reduced cooling in unoccupied zones. It also takes care of the indoor air quality, rapid cooling and automatic cold air balancing inside the office. Variable Frequency Drive (VFD) is liable for energy savings by modulating the motor speed to regulate the fan speed, consequently controlling the amount of cold air pumped into the office. Based on the fan speed, the required water flow is further optimized,therebydecreasingthe load on chiller and pumps resulting in a massive reduction of the power bills. This precise control on AHU chill water maintains the Chill water Delta T in a band of 4 - 5°C, which increases chiller efficiency and AHU performance.The in-built BTU meter displays the instantaneous power consumption that incentivizes people to further act upon reducing the power consumption. Individual components of Green HVAC communicate with each other by Standard Modbus protocol which makes the integration more straightforward.

The cost comparison amidst conventional and Green HVAC system demonstrates that the later saves approximately 23% in the cost of air-conditioning. The cost of automation is also drastically reduced due to the lesser number of components required in Green HVAC system. As part of the monthly running cost, the customer also saves up to 35% every month in Green HVAC system compared to the conventional system. The value propositions to customers obtain in this system makes the Green HVAC commercial, and easily sellable.