Case Study

Optidrive controlled smoke extraction systems

Optidrive controlled smoke extraction systems

Problem

The market was undergoing substantial regeneration and a new smoke control and extraction system was needed. The control system would need to comply with the latest building and safety regulations. The project required reliable variable frequency drives to control the speed of smoke extraction and pressurisation systems inside the high rise building – previously systems relied on mechanical and electromechanical dampers that needed regular maintenance and adjustment.

Solution

Optidrive Eco HVACs were used to control the smoke ventilation systems. With its Fire Mode maximum duty/running time is obtained when operating in a fire condition without the concern of loss of control due to overload and over temperature issues. The VFDs also provide increased efficiency of the systems which reduced energy costs.

Rathbone Market

Optidrive Eco HVAC variable frequency drives from Invertek Drives have improved safety and greatly reduced energy usage in HVAC systems installed as part of the major redevelopment of Rathbone Market in East London. Crawford Controls, one of Invertek Drives' UK sales partners, completed installation of 11 Optidrive VFDs in the Rathbone development, working with smoke ventilation and fire engineering specialist, Interactive Special Projects Ltd.

Rathbone Market was undergoing substantial regeneration which will resulted in a a new market, homes, retail and commercial units on the historic site. Interactive Special Projects was contracted to supply smoke control systems for the project to ensure compliance with the latest building regulations.

Interactive employs a wide range of the latest technology to ensure that buildings and escape routes are maintained free from smoke and fumes for the occupants, as well as a clear means of access for fire fighters and other emergency services.

The project required highly reliable VFDs to control the speed of smoke extraction and pressurisation systems inside the high rise building – previously systems relied on mechanical and electromechanical dampers that needed regular maintenance and adjustment. Operators didn't have any control over extract rates with the old system either - fans ran at full speed regardless of the necessity.

Interactive contracted Crawford Controls to design, build, supply and commission the control systems that included Optidrive VFDs that have been developed specifically for HVAC applications. Crawford Controls has many years experience of smoke ventilation installations and utilise the specific Fire Mode facility that the Invertek Drives Optidrive Eco offers. This ensures maximum duty/running time is obtained when operating in fire condition without the concern of loss of control due to overload and over temperature issues. The contract award was based on a number of factors including low maintenance requirements, reliability, energy efficiency, economy and controllability.

Interactive Senior Consultant, Andy Baker, said: "The significant reduction in energy consumption that will result from installing the Optidrives mean systems can now be used for day to day ventilation - running fans at low speeds on a daily basis. The system originally designed was a stand by fire only set up using additional fans for environmental ventilation and therefore not cost effective.

In the event of a fire, fan speeds are automatically optimised. Using PI pressure sensing control the new systems are far safer than older versions - lobby pressures are limited, minimising the likelihood that people may get trapped trying to escape a hazardous situation."

Optidrive Eco has been specifically designed to deliver improved performance, control and energy savings in fan and pump applications in building services and is available from 0.75kW to 250kW power outputs with IP20, IP40, IP55 and IP66 enclosure options. The drive features BACnet and Modbus on board as standard, plus energy optimisation, fire override and noise reduction functions.