PENGHEMATAN ENERGI PADA BANGUNAN DENGAN MENGINTERVENSI SET POINT PADA HVAC BERBASIS PADA KEADAAN PENGHUNI DI DALAM GEDUNG

• Main Author: ARDIYANTO (NIM: 23216030), DIMAS
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/26655
• Institution: Institut Teknologi Bandung

Energy savings and occupant thermal comfort are the two most important factors in controlling heating ventilation and air conditioning (HVAC) operation in buildings. Thermal comfort is typically measured by Predicted Mean Vote (PMV), which is derived using information on air temperature, radiant temperature, air velocity, relative humidity, metabolic rate and clothing isolation. In typical buildings, it is found that thermal comfort is not always met. Hence, there is still an opportunity to improve indoor thermal comfort, and at the same time save energy by controlling HVAC set points. The objective of this research is to propose a method to obtain energy savings by adjusting HVAC set points based on occupant comfort measured using PMV and occupancy information. The idea is to calculate hourly PMV values based on real-time occupancy information, indoor temperature set points and humidity in a building. Then, a new set of temperature set points that can maintain occupant comfort, i.e., PMV = 0, is derived. <br /> <br /> To evaluate the effectiveness of the proposed method, a building model is developed in eQUEST using the information from a real-world building located in Alexandria, VA. The building has three zone groups which are office, storage and warehouse. An occupancy sensor and a Netatmo weather station have been deployed in a laboratory environment to record hourly occupancy and temperature/humidity information for PMV calculation. The data have been recorded over the period of three months and used as inputs to the eQUEST building energy simulation model. Energy savings is quantified by comparing the base case scenario (that has the set point of 72.5oF during occupied periods and 86oF during unoccupied periods, using the measured occupancy numbers) with the case that has new temperature set points adjusted based on PMV value. Research findings indicate that HVAC electrical consumption savings of 14.58% are achieved when the proposed set point adjustment method is implemented as compared to that of the base case. To study the impact of adding occupancy information on HVAC energy savings, another scenario is simulated where HVAC set point is increased when the building is unoccupied, e.g., during lunchtime or holidays. Research findings indicate that additional HVAC electrical consumption savings of 8.79% are achieved when taking into account occupancy information in HVAC control. Another objective of this research is to predict the HVAC set point temperature that satisfied thermal comfort for occupant using multiple regression and the value of PMV, the old HVAC set point temperature before PMV value is zero, CO2 levels (ppm), the number of people in the building and also the outside temperature as the independent variables and is expected to be used in near future and may help the building owners to save the energy consumption in their building. <br /> <br /> Overall, it can be observed that both thermal comfort and occupancy numbers have an impact on electrical energy consumption of HVAC units. This research presents a method to save energy by performing on-demand HVAC set point interventions– based on thermal comfort and real-time occupancy information and demonstrates how HVAC electrical consumption can be reduced. It gives an insight into the impact of thermal comfort and occupancy in reducing the AC electrical consumption. <br />