Case Study 1

We built an entirely new system around the occupants of a 17 story high rise tower without interrupting normal working hours.

Summary

Full replacement of a BMS system in a fully tenanted building, as the building transitioned from an inefficient Condenser Water System (Compressors) to a high COP Chilled Water (Chillers) system.

The Problem

The existing Mechanical AC system was at the end of its life, as well as the control system. This had caused high energy costs, near daily comfort complaints from occupants, simultaneous heating and cooling wasting energy and an inability to maintain comfort conditions due to control system limitations and inaccurate zoning.

Due to the building being occupied, air conditioning interruptions were not acceptable. So our challenge was to design and implement a BMS system that could be installed ahead of the mechanical demolition teams, take over control of the old compressor system to maintain AC system operation, and then transition to full chilled water Air Handlers out of hours with immediate control after cutover.

The Solution

We achieved our project goals by staging the networking and field installation works in a specific way to ensure we had the airside (119 VAV’s) installed and running prior to the air handler cutovers, and writing a BMS control program with the capability to switch from one type of system to another easily for a rapid changeover.

Because we had full control of the existing AC systems in advance we had insight into the additional anomalies and “unknowns” present within the existing system, which we shared with the Mechanical and Electrical contractors to ensure solutions were found and implemented ahead of time.

Result

System stability improved immeasurably – with happy tenants and occupants as a result. The new system maintains control using smart P/I (Proportional/Integral) control on flow variation and set point resets, resulting in very consistent zone temperatures, improved airflow and air quality consistency. To guarantee long-term reliability we used only high accuracy sensors, HVAC pattern recognition and High Level Interfaces to all new equipment.

By implementing our Optimal Start/Stop algorithm, the new BMS only runs for as long as absolutely necessary – and only as hard as required to achieve desired conditions without “Over Conditioning” the spaces. As for energy – an overall decrease of approximately 70% of the power consumption of the air conditioning system was realised.

Even the “Temporary” control system had an immediate impact on energy and comfort – electricity consumption dropped

For the occupants, the improvement in control and stability was like night and day.