Challenge
The building’s heating system was previously regulated with a control system based on heating curves that did not take heating demand into account. This resulted in energy waste and the building was easily overheated. The challenge was to control the heating system according to demand while ensuring thermal comfort for the occupants.
Approach
Spectral installed sensors to measure zone air temperatures and implemented active control to regulate the heating system based on heating demand. The temperature setpoint was gradually reduced by 0.5K each quarter to ensure occupants could adjust to the new temperature. The Air Handling Units (AHUs) were operated at lower supply air temperatures, and the secondary hot water temperature was regulated based on the measured zone air temperatures.
Outcome
After active control was implemented, the mean average zone air temperatures stayed close to the desired setpoint, resulting in reduced energy waste. Spectral recommended reducing the temperature setting on the thermostatic valve of the radiant floor heating circuit in the entry zone to prevent overheating. Spectral also suggested that the heating valves and supply air temperature sensors on the air handling units be inspected and repaired or replaced to improve their performance. Overall, the project successfully helped control the building’s heating system to meet demand while maintaining thermal comfort for occupants, resulting in less energy waste.
