200 Braddell Road Singapore 579700
Building and Construction Authority
Development of a High Energy Efficient Hybrid-Passive Displacement Ventilation System
- Project Key Words:
- Hybrid-PDV, Modular Chiller, VRF M & V System
- PI:
- Mr. Kelvin Chay
- Organization:Yitac Ptd Ltd
- Designation:General Manager
- CO PI(s):
- Mr. Tan Seow Kee
- Organization:Yitac Pte Ltd
- Designation:Manager
- CO PI(s):
- Mr. Lam Kwok Ho Sam
- Organization:Ngee Ann Polytechnic
- Designation:
- CO PI(s):
- Mr. Tan Swee Ching
- Organization:National University of Singapore
- Designation:
- Collaborators:
- Nil
- Project Period:
- 01/12/2020 To 30/11/2021
- Project Description:
- Hybrid-PDV System
The Hybrid-Passive Displacement Ventilation (PDV) is a chilled water based air-
conditioning system that uses high efficiency DC inverter compressor and plate heat
exchanger to produce chilled water to serve passive displacement cooling coils that
provide space cooling with zero air-side energy. This revolutionary design minimizes
the need for expensive and on-going leak detection system needed for direct
refrigerant gas system.
As the Hybrid-PDV system is a chilled water based system, it will provide
comfortable, stable air temperature control in a quiet and energy efficient manner.
Hybrid-PDV system is a truly integrated cooling solution for office buildings, hotels,
hospitals, medical centres, schools, high-rise buildings, shopping centres and other
commercial premises, where occupant comfort is paramount.
Easy Installation & Operation
The system is modular in design so it can cater to different load requirements by
simply combining cooling modules in parallel. This allows installed capacities of up to
700kW to be achieved. The small footprint and modular design means building
owners can now take advantage of a manageable phased installation.
Key Features and Benefits
• The Hybrid-PDV system uses a chiller that adopts variable refrigerant flow
technology that allows it to vary its cooling capacity automatically according to
external load demand with constant chilled water leaving temperature.
• The chiller leaving water supply temperature can be set to produce chilled water
from 6 °C to 20 °C.
• Zero energy is consumed for space cooling as the Hybrid-PDV system uses passive
cooling (PDV) coils to provide space cooling.
• As water instead of refrigerant is circulated through the indoor PDV coils, good
thermal comfort, good indoor air quality and quiet operation is assured.
• Installation is simple and requires low maintenance.
Application
• Hybrid-PDV system is a truly integrated cooling solution for office buildings,
community halls, medical centres, schools, multi-tenanted buildings, shoppin
centres and other commercial premises, where the cooling requirement is less
than 200RT (700kW).
• It is a viable alternative to the VRF air-conditioning system and can be used in
facilities where chilled water supply is not made available.
• It can be used to serve buildings that has facilities operating outside normal
chiller operating hours such as buildings with cinemas, call centres etc. without
the need to operate the main night chiller.
• It can be used as a secondary chilled water plant to smoothen out spikes in
cooling loads in commercial building that has high load spikes.
- Lead Organization:
- Yitac Pte Ltd
- Project Impact
- The test results shows that the Hybrid-PDV system can be operated with lower
energy, capital and maintenance cost. This makes the Hybrid-PDV System a
viable and cost effective alternative to existing VRF cooling system or
conventional air-cooled system that requires less than 200RT cooling.
With this system, it is now feasible for facilities such as multi-purpose hall,
vertical farms, schools, low rise commercial/industrial to be equipped with a
chilled water system. It also provides building owner a wider choice of air-side
equipment (e.g. PDV system, chilled beams, AHU, FCU etc.) to serve their
specific cooling needs such as for:
- Cooling System for Vertical Farming
- Standalone Cooling System for Multi-Purpose Hall
- Warehousing
The Hybrid-PDV System has enabled building without a chilled water system to
implement the PDV system and allow users to reap the benefits of using a PDV
system.
- Project status:
- On-Going Completed Terminated
- Project Outcomes:
-
Project Objective
The objective is to develop an efficient Hybrid-PDV system that can provide cooling
to small scale buildings/facilities that have less than 200RT (700kW) cooling load. The
system shall generate chilled water efficiently and be used to serve a variety of air-
side equipment such as Passive Displacement & Ventilation System (PDV), Forced-
Circulation System such as Air-Handling Unit (AHU) or Fan Coil Unit (FCU) or other
passive air-side equipment. It can also be used as a heat recovery equipment to
produce hot water.
Key Deliverables
The key deliverable is that the Hybrid-PDV system is able to provide cooling at an
average Total System Efficiency (TSE) of less than or equal to the GM ENRB: 2017
Platinum Standard TSE of 1.03kW/RT.
Results Achieved
Based on the test results, the following Total System Efficiency (TSE) were achieved
for the Hybrid-PDV System:
• Hybrid-PDV using York Chiller – Average TSE 0.996 kW/RT
