Improving thermal comfort and energy efficiency at Clean Tech One

The Energy Research Institute @ NTU (ERI@N) offices at Clean Tech One are cooled via a centralized chiller which distributes chilled water to individual Fan Coil Units (FCUs). The flow rate of the chilled water circulated is controlled by a solenoid valve in the return line of FCU – controlling the flow rate is essential for efficient cooling of a space. One common complaint made by occupant is that the offices can be “overcooled”, leading to thermal discomfort. This in turn leads to both energy wastage and thermal discomfort.

Challenge

ERI@N is looking for solution(s) that eliminates thermal discomfort from overcooling, while at the same time maintaining or improving the energy efficiency of the cooling system.

The proposed solution should:

1. Readily integrate with the existing systems at Clean Tech One, with minimal down time (max 9 days, i.e two weekends)
2. have a TRL of >=7
3. achieve thermal comfort at least 95% of the time
4. achieve energy savings of 5-10%

1. To improve energy efficiency of Clean Tech One’s ACMV systems by reducing the occurrence of overcooling.
2. To improve the occupant comfort levels at ERI@N’s offices.

• High frequency and high responsive solenoid valve
• PID controlled valves
• Special control circuit
• Special control algorithm
• Hybrid cooling for the office  

6 month R&D + 6 month testbed

• Testbed/ Trial site (envisioned deployment site): Clean Tech 1 – Level 1 - 02-24 (2 FCUs in a 146m2 office space)
• Number of occupants in the office vary daily (avg 10, max 25). Applicants may want to allocate time/resources to study occupancy patterns when proposing solutions.