The world is constantly changing; as do people, technologies, ideologies and, most pertinently, buildings. Changes that directly affect condominium buildings include changing demographics of residents, building envelope deterioration and converting space within buildings to functions that it wasn’t designed for. All these changes affect how you would manage a building from a Property Managers perspective, but also need to be addressed from a mechanical operations perspective. HVAC (heating, ventilation and air-conditioning) is the heart of a condominium building; it is vital to a healthy home for residents, pumping clean fresh air (and hallway pressurization), critical heating and comfortable cooling to all areas of the building. However, HVAC systems are typically installed during the original construction of the building and commissioned (whether this is done properly also is often questionable) for the original design of the building by the builder. It is very common for the builder to try to complete the construction and set the occupancy date as soon as possible, so that they can request payment sooner; even if this means some “nuts and bolts” are forgotten. Hopefully, the Property Manager will identify these deficiencies within the warranty period and have them corrected; however, this is sometimes overlooked. Over time and use, mechanical equipment is replaced, repaired or abandoned and engineering designs change, and, suddenly, you won’t even recognize your mechanical room. This is where re-commissioning becomes very important.
Re-commissioning (also called retro-commissioning) is defined as the re-optimization process for existing buildings that improves a building's overall performance by optimizing energy efficient design features and directly addressing equipment performance and system integration issues (NRCan OEE 2011). It can be a one-time event, but more often is performed routinely every 2-5 years. Some re-commissioning can be done by building staff, but it is recommended that a proper re-commissioning agent (typically a professional engineer) lead the re-commissioning team to ensure quality and knowledge of best practices.
“Re-commissioning is a great opportunity for condominiums”, says James Mann, President of Mann Engineering Ltd., “not only because of the cost savings, but because you are improving the comfort of residents and increasing the lifespan of equipment. And while it’s obvious that older buildings will benefit from this, brand new buildings will often benefit too.”
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) sites energy savings of 20% and a two-year return on investment resulting from re-commissioning case studies (ASHRAE 2011).
In 2012, Enbridge Gas Distribution decided to offer a re-commissioning program, called Run-It-Right, to buildings that consume more than 300,000m3 of natural gas. Mann Engineering partnered with Enbridge on this initiative and was able to re-commission over 25 buildings for clients at no cost to them. Furthermore, Mann Engineering will be monitoring these buildings for the next year and providing energy savings reports to show the actual energy savings from the re-commissioning.
“The Enbridge Gas Run it Right program focuses on three (3) core concepts – Benchmarking portfolio of buildings, Re-commissioning Activities (Training/Education) and Monitoring/analyzing effects of re-commissioning activities,” says Paul Abate, Marketing Program Manager for Enbridge. “Enbridge has formed alliances with key re-commissioning training providers to assist and train natural gas customers to implement operational measures. These sessions will provide value added technical expertise for building operators.”
The scope of work for a re-commissioning varies by building, but should include, at a minimum, reviewing all temperature setpoints and control sequence of operations (heating, hot water, ventilation and cooling), reviewing the schedules and controls for make-up air units and exhaust fans, checking for equipment inefficiencies, balancing the air-distribution from the make-up air unit to the hallways, verifying temperature sensors and control points are working properly, reviewing equipment runtimes and trend logs (if available) and correcting deficiencies. Re-commissioning should be done alongside the building staff and residents, not in spite of them. It is important that the re-commissioning agent actively discusses suggested adjustments with the building staff and, when necessary, residents to ensure that the changes are agreeable and sustainable. Training site staff and ensuring they have proper documentation is an important part of re-commissioning.
Re-commissioning of a condominium building often starts with the controls installed on the HVAC equipment. For buildings with a building automation system (BAS), the re-commissioning agent will have ample information available to fine-tune the equipment operation and can work with the building to program tighter setpoints and schedules for further energy savings. For buildings without a building automation system, the re-commissioning agent will have to check the controls for individual equipment, noting opposing or redundant operations. Both arrangements can benefit significantly from regular re-commissioning.
It is not uncommon for a client to start with a basic re-commissioning and add additional scopes of work (such as thermographic scans of the building envelope or controls upgrades) through the process. A re-commissioning report will describe the conditions before the re-commissioning and the actions taken for improvement, noting identified deficiencies and inefficiencies. A re-commissioning report should also make recommendations for further improvements beyond just re-commissioning, such as capital upgrades for equipment and controls, changes to the sequence of operations, or design changes. As a result, re-commissioning can help you develop a new roadmap, or continue with an existing roadmap, to a greener building.
Mann Engineering Ltd has been a leading energy management service provider in Canada since 1988. Headquartered in Toronto, Mann Engineering offers a comprehensive approach to re-commissioning multi-residential, commercial and industrial buildings. Mann Engineering also offers mechanical, electrical and structural consulting engineering services as well as full in-house construction capabilities for boiler retrofits, chiller and cooling tower replacements, and advanced building automation system installations.