PROJECT DESCRIPTION

MAT 4Site Engineers was retained for the engineering work for the replacement of the existing steam heating system. The facility is occupied by the Government of Canada as an office building for the Canada Revenue Agency. The facility is designated as a heritage facility.

The existing heating source, steam supply from the district steam plant was scheduled to be disconnected. The project includes replacement of existing steam to water heat exchangers with new high efficiency heating boilers, retrofit of the existing perimeter heaters with new 2-way valves, new pumps and all associated equipment replacement. In addition new heating pumps were equipped with Variable Frequency Drives (VFDs), what allowed the facility to take advantage of the variable flow that would be caused by the perimeter system’s 2-way valves.

The humidification was provided through the air handling units throughout the facility (total of 13 units) by injecting low pressure steam (15 psi) directly into the air stream. The existing steam and condensate infrastructure presently used for humidification was reused. A new steam boiler was installed for this duty. As part of the new steam humidification system, a new condensate return system and a new feed water tank were installed along with water softeners.

The specific project details included:

• Decommissioning and demolition of existing steam equipment (heat exchangers, pipes) in the penthouse
• New hot water heating boiler system to replace the existing steam supply system for heating of the facility. New system consist of; three boilers, 2,500 MBh each for the low temperature heating loop and one 600 MBh for the high temperature heating loop.
• Replacement of existing heating system pumps with new VFD pumps
• New steam boiler system for humidification, 2,000 MBh c/w new feed-water and condensate return system;
• New local perimeter heating, 2-way control valves with tie-in to existing VAV supply air box controllers (approx 500);
• A new building automation system upgrade to an Open Protocol system (BACnet);

Services

Project services included feasibility planning, conceptual design, detailed engineering & design, construction review, contract administration and commissioning.