HEALTH CARE: Vancouver Island Cancer Centre
August 1, 2002
By Canadian Consulting Engineer
Keen EngineeringThe Vancouver Island Cancer Centre adjacent to the Royal Jubilee Hospital in downtown Victoria, British Columbia was built on a fast track schedule with the aim of reducing waiting tim...
The Vancouver Island Cancer Centre adjacent to the Royal Jubilee Hospital in downtown Victoria, British Columbia was built on a fast track schedule with the aim of reducing waiting times for cancer patients. Opened in 2001, it is one of several new buildings on the site and has connections to the main hospital’s new Diagnostic and Treatment Facility. The Cancer Centre replaced an ageing cancer treatment building and is owned and operated by the B.C. Cancer Agency. It is a 8,360-m2, three-storey building, with circulation routes radiating off a Y-shaped central lobby.
Keen Engineering’s Victoria office was responsible for the heating, ventilation and air-conditioning. They used a dual fan/dual duct air-handling system, as well as twin air-cooled chillers. Tom Wilson, P.Eng., a principal and Victoria regional manager at Keen, admits: “It’s not the kind of system you’d use in every building by any stretch of the imagination.” Still, they found that a dual system is very functional for health care installations. “The main reason is that we can maintain precise indoor climate conditions. Regardless of whether the system is trying to heat or cool, we can precisely control the amount of ventilation air.” He also finds that that the dual system gives energy savings and can be easily modified.
The system has two custom-built air handling units located in a penthouse mechanical rooom. One unit provides for the hot deck, the other provides for the cold deck. The two units are interconnected and calibrated in such a way that in low load situations one fan can service both sides, giving an improved energy performance. The air handling units incorporate all the heating, cooling and heat-reclaim coils, filtration systems, motorized dampers, fans and variable speed drives used for air volume control. Control of the supply air is also orchestrated to work with the exhaust system. This approach has particular energy advantages in this building because it is only when the laboratories are occupied that they are venting and create a heavy demand for replacement air.
More than 20 per cent of the building area consists of laboratory and research space. The laboratories are served by a central exhaust, whereby the fume hoods feed into one manifold. This 30-foot high chimney is carefully positioned to ensure that the exhausted air is not ingested into the building. A central system is more reliable since the individual workstation fans provide back-up for each other. The engineers were able to specify one higher quality exhaust fan rather than several lesser quality fans, and maintenance is easier and more cost effective. There is also a central bio-safety cabinet exhaust system and a central radioactive exhaust system.
A sophisticated pressure balancing control maintains the air pressure of individual spaces inside the laboratories. This in turn is tied in with a centrally controlled, automated direct digital control (DDC) system that provides a cost-efficient method of monitoring and adjusting the operations. It allows the indoor air quality to be monitored and modified from a remote location if necessary.
In massive concrete vaults in the basement are six linear accelerators used for cancer diagnosis and radiation treatment. To keep this critical equipment cool and operating effectively, the accelerator’s internal cooling system is connected primarily to the central chiller, and secondly to the domestic system as a back-up. To prevent radioactivity escaping, the engineers had to offset the duct and pipework in these rooms to ensure that there are no straight lines of sight from inside to outside. The walls and all the pipework in the rooms are shielded in lead.
Client: B.C. Cancer Agency
Mechanical: Keen Engineering (Matt Younger, P.Eng.)
Prime consultant: Merrick Architects Ltd.
Structural: Bush Bohlman and Partners
Electrical: RA Duff and Associates
General contractor: Campbell Construction
Project managers: B.C. Building Corporation