Optidrive HVACs installed in major redevelopment of Rathbone Market.

Optidrive compact AC 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, recently completed installation of 11 Optidrive variable speed drives in the Rathbone development, working with smoke ventilation and fire engineering specialist, Interactive Special Projects Ltd.

Rathbone Market is currently undergoing substantial regeneration which will result in 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 variable speed 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. 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 VSDs that have been developed specifically for HVAC applications. Crawford Controls has 15 years' experience of Smoke Ventilation Installations and utilise the specific Fire Mode facility that the Invertek Drives HVAC drive 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, says, "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 HVAC 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. Full details can be found by visiting the dedicated HVAC building services section.

Find out more about Rathbone Market's conversion by visiting www.rathbonemarket.com.