Region of Waterloo Lab - Fume Hoods Replacement and AHU Upgrade


The Region of Waterloo environmental laboratory building is single story, sprinklered and standalone, facility measuring approximately 10,000sf. The facility consists of several laboratories and a large office area. The existing fume hoods in the laboratories have passed their expected life time and had numerous issues with air flows and face velocity and therefore did not comply with today’s guidelines. This project involved the engineering for the replacement of the laboratory fume hoods (total of 14) and upgrade of the base building air distribution system. Project services included feasibility study, engineering design and construction review and contract administration.
The project has been carried out in two phases. Phase 1 includes the replacement of the fume hoods and VAV boxes in labs and upgrade of the control system. The second phase includes the replacement of the air handling units located in the penthouse c/w all associated equipment (condensing units, humidifiers, boilers, etc).

A feasibility study was completed for the ROW. The study involved a detailed review of various types of the laboratory fume hoods (low flow vs standard flow) with advantages and disadvantages. Following the study we had provided guidance to the client through the fume hoods selection process to best suit their needs. The design was provided with the standard flow hoods which required higher rate of the make-up air from the building but provide more comfortable environment for the client’s needs.

A subsequent study of the existing Air Handling Units (AHU) and existing cooling systems was also conducted in Phase 1. This detailed study focused on the condition of the AHUs and cooling equipment to determine their existing condition and capacity. It was determined that both AHUs were at the end of their useful lives and that the AHU serving the lab areas was undersized for the expanded program requirements. The supplemental cooling systems were in good condition. An ultimate recommendation and work plan was developed that culminated in the initiation of Phase 2 that would involve the replacement and upgrade of this equipment.

Phase 2 involved the replacement of the facility’s two main AHUs, condensing units, boilers and all related controls. As this would have been very disruptive to the programs within the facility, a temporary ventilation system was also designed to allow the building to function during the course of the work.

Due to higher required volumes of the make-up air we have designed for replacement of several VAV boxes, exhaust terminals and upgrade of the Building Automation System to DDC to maintain proper air pressure in the laboratories.

The project also included removal of the charcoal filters from the fume hood strobic exhaust fans which was approved through the application to the Ministry of Environment. The system was constructed and exceeded all clients’ requirements

It was also noted by our staff that the existing facility lacked the necessary separation of potable and laboratory water systems; and that the facility lacked the correct level of backflow prevention from the municipal water supply. The issue was rectified with a design that provided new backflow preventers, and new water supply piping that separated the lab and potable systems.

Challenges and complexities overcome for this project that would be relevant for work in this category included:

• Phasing the project to replace fume hoods in one lab at the time and ensuring all work was capable of being constructed in this 24/7 operation facility with clean environment;
• Maintaining system operational during the air handling units replacement including temporary equipment;
• Ensuring minimal disruption to the facility’s functions throughout the construction period.
• Integrating the new and old systems to function harmoniously.
• Working within existing facilities and systems (some of which contain hazardous substances)
• Working in occupied facilities
• Being mindful of long lead items and creating a strategy to minimize impacts to schedule (such as pre-purchasing of items)
• Improving existing systems and creating more energy efficient systems and buildings in the process
• Ensuring all systems are properly commissioned

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