Chapter Winner

Category: Health Care Facilities for an Existing Facility.

Submitted by, Robert McLean, P. Eng.

Avalon Mechanical Consultants Ltd.

Royal Jubilee Hospital Diagnostic and Treatment Centre,

Heat Recovery Chiller Phase 1

Project Summary:

This project was to add heat recovery chillers (HRCs) for Island Health in the Diagnostic and Treatment (D&T) building at the Royal Jubilee Hospital. The D&T building contains operating rooms, laboratories, MDRD, morgue, computer rooms, imaging, emergency department and various administration and support spaces such as general stores, pharmacy stores and major mechanical rooms. This project affects the entire building, approximately 500,00 square feet.

The HRCs take condenser water from the main hospital chiller plant before it goes to the existing cooling towers.  This warm water is used, through heat recovery chillers, to preheat the building heating water loop before it goes to an existing steam to water heat exchanger. The building uses heating water year-round in a constant volume reheat system.

Project Criteria:

Energy Efficiency: It is anticipated this system will operate when the chillers are running through the cooling season with estimated gas savings over 7000 GJ annually and over 350 tons of greenhouse gas emissions. A phase 2 and 3 of the project, to be constructed by March 2021 will add year-round chiller loads and thus year round heat recovery.

Innovation:

The project utilized existing infrastructure and took what was previously waste heat and converts it to useful heat. Although this is not new technology or a new use of existing technology it is an innovative method of reclaiming waste heat by capturing it before it is rejected to atmosphere. Due to the requirement of reheat in the building even during the height of the cooling season this waste heat capturing diverts steam load, previously used to make the reheat hot water, from the main  boiler plant and reduces natural gas consumption for the site.

Operation & Maintenance:

An added benefit to the operation of the condenser water systems is that this project introduced a large surface area mesh strainer which helps remove particulate (dust, pollen, rust from the open system) from the condenser water thus providing a cleaner and less abrasive water system, reducing wear and prolonging the service life of the pumps, chillers and cooling towers.

Cost Effectiveness:

This heat recovery system provides net savings of approximately $63,000 annually.

Environmental Impact:

The reduction of natural gas usage due to the preheating of the building heating water equates to over 350 tons of greenhouse gas emissions deferred annually. This is the equivalent emissions from 75 typical cars.