Public Works & Government Services Canada 

Tunney’s Pasture

HH Angus was engaged as Prime Consultant on a chiller plant installation for this public building in Ottawa. The project installation serviced nineteen buildings with a total floor space of ~3,170,000 ft2 and was comprised of two chillers @3500 tons. 

Tunney’s Pasture is a 49-hectare (121 acre) mixed-use campus in Ottawa, including government services, commercial offices and residential buildings. Its existing steam-driven chillers were at end of life and operating with R22 refrigerant, the import and production of which is banned as of January 2020. Also, the use of river water for free cooling needed improvement and the river water pumping system was not operating efficiently.

HH Angus, in joint venture with Goodkey Weedmark, was retained to undertake conceptual studies to evaluate changing the chillers from steam power to electrical power. We also made recommendations for improving the free cooling aspects of river water and making more effective use of the river water pumping system.

HH Angus provided conceptual evaluation of replacing the chillers, in terms of efficiency, physical location and necessary steps required to change from steam to electrical power. Once the chiller concept was resolved, we evaluated optimization of the river water pumps to undertake the condenser water cooling and considered how to efficiently use the free cooling available from the river in low load conditions.

Optimizing free cooling and condenser water, using river water instead of cooling towers, resulted in energy efficiency and reduced carbon footprint for this installation. We also identified benefits to the client through improvement in chiller efficiency using the latest technology, and the elimination of boiler operation during the summer months.

Prime Consultant | Mechanical Engineering | Electrical Engineering

Status: Completed: 2017

Ottawa, Ontario


Evaluation to optimize river water pumps to undertake condenser water cooling & efficient use of free cooling from the river in low load conditions | Consulted on technology that would eliminate boiler operations during summer months