Despite the challenges of working with increasing economic restraints, little changes in maintenance and operations can significantly impact the efficiency of a facility. While such energy savings can result from capital planning and proactive maintenance, a large portion of savings can be maximized through occupant engagement, sustainable practices and ensuring components perform at optimum level.
Taking all these factors into account, there is a potential 30 per cent minimum cost savings in older buildings (30 plus years) and up to 15 per cent savings in newer facilities.
Industry members shared such insight into effective methods for lowering maintenance and operating costs in facilities that also seek high sustainability standards at The Building Show in Toronto last December. They weighed apparent challenges against simple energy efficiency measures that also help achieve full life expectancy for building systems. Regardless of newer technology, much can be accomplished when taking a closer look at reducing demand.
“The challenge is to not have a large backlog in repairs,” noted Peter Leong, associate vice president, Building Sciences, WSP Canada. “Once you start deferring repairs and maintenance, you’re going to end up increasing your cost and will be faced with worse challenges.”
Leong pointed out that asset management figures highly in the whole life cycle of a facility, from pre-design to maintenance. Especially in newer facilities, asset management helps determine future planning and strategies. That said, he highlighted three basic maintenance strategies: corrective, preventative and condition-based. Look at major capital items and when they are due for repairs. Identify both significant and insignificant items, the maintenance strategy appropriate for each, what kind of regular intervals are needed and when condition will be assessed and activities performed. The key is to optimize a strategy according to when components will be maintained over their lifetimes and be as proactive as possible.
Energy efficiency measures
Ariel Feldman, project principal and technical lead at WSP, used an example of a leaky faucet to demonstrate simple cost savings. He said that one drop of water from a faucet, every second of every day for a whole year, amounts to $27 annually. Such small factors can have big impacts on utility costs, but are often overlooked. He also highlighted several short term paybacks inherent to mechanical systems.
High efficiency boilers have been on the market for a while. Knowing when to install these boilers depends on varying factors, so there are benefits to integrating capital planning into energy assessments. Feldman said a facility can receive a six to 16-year pay back if a boiler is replaced ten years into its life cycle. But when looking just at the incremental costs of moving to a high efficiency boiler, at the end of that boiler’s life cycle, the pay back drops to three to eight years. Sometimes it still makes sense to put in a high efficiency condensing boiler sooner rather than later, such as in a really old building with a 60 per cent efficient boiler. But for most buildings, he said, this won’t pay back effectively unless it’s integrated into a facility’s life cycle analysis.
The chiller plant will pay back in four to 12 years when you look at the incremental cost. If the chiller is just being upgraded, without the existing chiller running out of its life, a facility may not see the same payback or may not payback within the life of the chiller itself. That said, it is recommended that capital planning and energy auditing procedures should be integrated.
Look at upgrading air handlers when they begin to reach end of life. In Canada, high-efficiency natural gas burners can save enough energy to payback in two years. Facilities without economizers are missing out on the advantage of precooling in the shoulder seasons like fall or spring when it’s cool.
Feldman says that could pay back almost instantly. Other upgrades include high-performance casing, which pays back in four years. Advanced rooftop controls or retrofit measures, somewhat new technology, offer a one to four-year payback and can be added to an existing roof top unit.
A “perfect time” to conduct an energy audit is when a facility is reaching 25 to 30 years old, and various systems will need replacing.
“You get a sense of what opportunities are available before those [systems] start to fail and you are really panicking, trying to replace them as much as possible,” said Feldman.
An ASHRAE Level 1 audit offers a list of measures, but may not offer a financial analysis. That said, there are higher level energy assessments. An ASHRAE Level 2 energy audit delivers great value, which is why IESO has been offering incentives to pay for almost half of the audit. Costs vary depending on the size of a building. Generally, said Feldman, depending on what details are analyzed, a commercial building could cost about $25,000 to $100,000, with incentives covering half of this expense. An ASHRAE Level 3 audit focuses on the potential capital-intensive projects identified in Level 2, but with more detailed field analysis and engineering data.
For instance, if you have an idea of changing fan coil units to heat pumps and want to understand very specifically how it will affect your whole building, deep energy modeling might be needed. According to Save on Energy, audit funding includes detailed analysis of capital intensive modifications that identify potential capital-intensive projects from the electricity survey analysis. Detailed field data combines with in-depth engineering analysis to provide potential project costs and savings calculations. Other incentives stem from Toronto Hydro, Enbridge, Union Gas and PowerStream.
Retrocommissioning is a higher level energy assessment that involves looking at how a system is operating and what low and no cost measures can be implemented. If every measure is implemented, the average energy savings from a retrocommissioning job, including the cost of the consultant, is estimated to be 16 per cent with a 13-month payback.
Back in 2013, WSP retrocommissioned the Metro Convention Centre in downtown Toronto, and found a small steam leak that was occurring every minute of the day all year round.
“The steam usage we found was high in the summer, and this went unnoticed for a long time because domestic hot water runs off of steam,” said Feldman. “People assumed if it’s high in summer, people are using a lot of water. Turns out they were spending about $26,000 a year on this steam leak.”
Turning if off. Turning it down. Turning it back
“The cheapest kilowatt hour you’re ever going to pay for is the one you don’t use,” said Feldman. “So, turning a system off when it’s not in use is a no brainer.”
This thinking extends to lighting and carbon monoxide sensors in parking garages. Parking garage exhaust fans don’t need to be running all day; only when carbon monoxide reaches a certain level. LED lighting offers short-term paybacks. For instance, when considering maintenance costs related to high pole lighting in the exterior of a facility, payback from LED are less than a year with incentives. With precooling systems, take advantage of the cold air outside, and look for opportunities to turn systems down. During colder months, heat pumps don’t need to be running at peak load on warmer days.
Issues can arise as building operations drift over time due to turnover. Operators may not know what their previous successor did. For example, said Feldman, maybe there is an override because some tenants asked for it, but ten years later, a new operator might not understand why the override still exists, but still decide to keep it in place.
Since tenants control about a third to half of the energy in a building, specifically commercial buildings, consider how and when these occupants use space and look for opportunities to reduce HVAC schedules, lighting or flood loads.
After a delving into other various energy efficiency measures, Feldman summed up the process of implementing a project. Use expert advice and start with energy assessments and capital planning as soon as possible so strategies are in place when equipment begins to fail, Develop a plan and ensure funding is available when it needs to be. Budget for training as systems, especially new management software, is only as good as the people operating it. Once implemented, celebrate success and monitor performance to guarantee benefits.