Digitizing a School

ST. JOSEPH’S COMPOSITE HIGH SCHOOL RENOVATIONS, EDMONTON

HEMISPHERE ENGINEERING

St. Joseph’s High School in Edmonton’s inner city was originally built in 1931, with additions in 1951 and 1966. However, last year this elderly building was transformed into one of Edmonton’s most innovative learning centres for a student population that is expected to grow to 1,600. Hemisphere Engineering overhauled the mechanical and electrical systems throughout the 30,200 square metres of space while the building remained operational. The project won an award of merit for its infrastructure in the Consulting Engineers of Alberta Showcase Awards 2000.

Electrical and lighting

The school’s existing electrical systems dated to the 1950s and 60s. Lighting quality was generally poor, and the electrical power distribution needed to be upgraded to ensure quality power to approximately 600 computer workstations. The complete new infrastructure systems for communications, security and life safety had to be fitted within the existing concrete and block walls, and the ceilings.

The engineers changed the centralized electrical systems to a decentralized configuration. They added new small electrical rooms on each floor to form vertical risers at the south centre and north centre area. The riser rooms contain power distribution at one end of the room, and communication, low voltage and wired building infrastructure at the other.

In the basement main electrical rooms the engineers replaced the 208-volt substations with 600 volt substations. In place of the central 208 volt buss riser, they added separate step down transformation at each floor’s electrical riser room to handle the needs of that floor and to ensure high quality power to the computers. Lighting and mechanical loads are sourced directly from the main substations.

The large open interior workspaces presented a lighting challenge. The designers had to minimize the contrast of artificial lighting with bright natural light from a 30 ft. x 30 ft. light well that was inserted to penetrate three floors. They needed to maintain a uniform appearance across the ceiling and provide low glare lighting for the computer workstations. The chosen solution was three-lamp recessed fluorescent luminaires with variable switching. The entire area has low glare lensing, which gives wider vertical distribution and requires less maintenance than parabolic lens lighting.

Computers and communications

The computer learning centres are located throughout the school, requiring an infrastructure that is being used as the basis for a University of Alberta graduate course in networking that is partially taught at the site. The site has also been selected as an APPLE partnered school facility.

Two of the electrical riser rooms have been customized as central hub rooms for the large digital network cabling system (the power transformers are located in the room above or below to minimize electrical disturbance). From these hubs, approximately 2,000 data cables are terminated to patch panels and hubs, and connected to a full fibre optic backbone loop. A separate server room (located in the third floor north computer centre) is connected to the fibre backbone.

Mechanical systems

As each addition was made to the building, a new mechanical system had been installed, each with its own steam or hot water boiler plant. The result was a system so complex that it was an operational nightmare for the maintenance staff.

As part of a major retrofit, the engineers added new air systems that use fresh air cooling, and replaced the existing hot water pipe system with a new hydronic system that uses less pipe and reduces the energy load by 85%. One of the boiler plants was demolished and the remaining two systems were interconnected to provide back-up heating.

A new direct digital building management and control system has centralized the plant operations and further reduced energy use. Integrating a network of controllers, the system allows the operator to adjust the individual space conditions. Now, students and staff working in the several parts of this venerable school building can be comfortable.CCE

Client: Edmonton Catholic Schools

Mechanical and electrical consulting engineer: Hemisphere Engineering (Vernon V. Mantai, P.Eng., Robert A. Campbell, P. Eng.)

Prime consultant: Workun Garrick Architects