– St James House is a live office 11 storey block in Sheffield city centre which did not have any form of extraction within the toilet areas on each floor
– We installed a new ducted system down an existing riser and ran branches out to each toilet area.
– The size of ducting was slightly restricted by the items within the service riser, with this in mind we agreed with the consultant that we would keep the extraction velocities higher than usual (but within industry standards) to compensate.
– The toilet area design flow rates were minimal at 6 air changes per hour
– The single inverter driven fan sighted within a plant area on L11 was controlled via the buildings existing BMS
– Each branch off the riser ductwork had volume control dampers fitted to allow for full system balancing.
– Fire dampers c/w access hatches were fitted where the ductwork left the riser and as the ductwork passed through into the toilet areas.
– All installation works were carried out during nights shifts, the client arranged for security to be present while our team was onsite.
– The site supervisor had his SSSTS accreditation and an in-date emergency first aid qualification.
– Tower scaffold were not practical for working off so we allowed step ladders, this was incorporated into our RAMS, a step ladder permit to works was put in place.
– The new ductwork was fitted to the building fabric via standard Unistrut and screwed rod.
– Drop tests were carried out on each fire damper as they were fitted.
– Upon completion the ductwork was balanced by specialists, the design flow rates and volume were met.
– Documentation of the new fan, extraction system commissioning and the fire damper drop tests were added to the Operation & Maintenance manual.