Chicago’s buildings will soon resemble New York City restaurants.
No, they won’t be offering greasy pizza. But, like NYC restaurants, Windy City buildings will be required to post their “rating” in a prominent location. Instead of a health grade, Chicago ratings will focus on the building’s energy use—the first rating system of its kind in the U.S.
Beginning early August 2019, Chicago buildings 50,000 square feet or larger will be required to post their designated rating based on energy use, corresponding to the City of Chicago’s four-star flag. The intent of the rating system is to disseminate already publicly available building energy usage data in a way that is more understandable to the masses.
The new City of Chicago Energy Rating System will translate each building’s annual ENERGY STAR Portfolio Manager score into the one- to four-star rating. The current compliance deadline for the energy rating system coincides with the benchmarking ordinance: June 1, 2019.
Four best practices for benchmarking
According to the city’s 2017 energy benchmarking report, properties have reported annual average energy reductions of one to two percent, equating to over $39.2 million in cost savings. To put this in perspective, the total energy savings equates to over 1 million metric tons of CO2, equivalent to 2.5 million barrels of oil.
Those that have benchmarked and reported two years in a row save an average of 2 percent of their energy expenditure, or over $6 million in annual energy costs. According to 2018 statistics, cumulative city-wide energy cost savings since 2014 have reached nearly $61 million.
To improve a building’s ENERGY STAR and Energy Rating System score, consider the following low/no-cost measures that can save a building as much as 3 to 5 percent in energy expenditure.
1. Reevaluate building occupancy hours
Adjust HVAC temperature set points for specific areas of the building, based on tenant occupancy and schedule. When tenant office hours are from 8 a.m. to 5 p.m., schedule unoccupied set points before 8 a.m. and after 5 p.m. that are higher (for cooling), or lower (for heating), than the optimal occupied temperature set point. This will reduce the need to continually condition the space during unoccupied hours.
2. Schedule AHUs and check dampers and actuators
Delay the air handling units’ (AHUs) start time to as close to building occupancy hours as possible to limit unnecessary energy usage. Several factors, including age and performance, will dictate how close the unit can be started to achieve the desired temperature at occupancy. TIP: Trial and error is the easiest method to determine the optimal schedule.
Check the dampers and actuators on AHUs often to ensure they are operating correctly. Improper dampers and actuators may leak air into the building, thus requiring additional conditioning and energy to achieve the desired temperature. When dampers and actuators are past their prime and need to be replaced, a significant energy savings can be garnered. Have maintenance personnel check them quarterly. TIP: When the damper is moving/opening less than 30 percent, it’s time for a new one.
3. Retrofit lighting to include LEDs
Many Chicago high-rises still employ T8 or T5 lamps. Replacing them with LEDs is a quick and easy way to lower energy consumption. New LEDs may also be covered in the ComEd Energy Efficiency incentive program, as applicable.
With their long lifespan and low wattage, LEDs reduce first costs, operating costs and energy expenditure simultaneously. Even when it’s not possible to change bulbs in tenant spaces, moving to LEDs in the base building areas like elevators, lobbies and hallways will still make a difference. TIP: Consider including a clause in tenant agreements that require the use of LEDs—a move that will make LEDs a building standard and lower total building energy consumption. Also, depending on the building’s electrical infrastructure, an LED upgrade may require new drivers, which will add to the relatively low cost to change over.
4. Change filters
Changing and cleaning filters on a regular basis reduces the buildup of dust and debris which affects the static pressure of the system and saves energy. Include filter checks in your facility’s regularly scheduled annual maintenance program. When old filters aren’t changed, the air stream gets clogged, requiring AHUs to use more fan energy to achieve the required temperature and ventilation rates, thus increasing energy use. Less air to a tenant space can lead to thermal comfort issues and higher tenant complaints.
Still have a low ENERGY STAR score?
Buildings that have already picked the low-hanging fruits and instituted best practices will want to consider an energy audit or retro-commissioning. ComEd and Peoples Gas offer attractive incentives for optimizing building performance with no/low-cost measures from a professional service provider at no cost to the customer. They offer retro-commissioning (RCx), which identifies energy conservation measures, or continued monitoring-based commissioning (MBCx), which provides fault detection, diagnostics software solutions and energy conservation measure identification.
In addition to reducing your energy and operational expenditure, energy efficiency services like these often lead to an increased ENERGY STAR score, thus a higher City of Chicago energy rating.
Samantha Davidson, LEED AP, BD+C, is a Fitwel Ambassador and Energy & Sustainability Engineer at Environmental Systems Design, Inc.
