©2018 This excerpt taken from the article of the same name which appeared in ASHRAE Journal, vol. 60, no. 10, October 2018.
By Matt Branham, P.E., Associate Member ASHRAE
About the Author
Matt Branham, P.E., is a project manager and energy engineer with CMTA Energy Solutions, a division of CMTA, in Louisville, Ky.
The Kentucky Exposition Center (KEC), located in Louisville, Ky., features 1.2 million ft2 (111 484 m2) of indoor conference, arena, and exhibit space. The facility, which hosts a wide variety of events throughout the year, is the sixth largest in the United States. The Kentucky State Fair Board is responsible for managing and operating the facility.
Facility managers at the Kentucky Exposition Center were facing the steadily growing expense of operating and maintaining a 1956 vintage 45,000 lb/h (5.67 kg/s) inefficient steam boiler plant that served more than half of the facility. As an energy conscious owner their goal with a replacement project was to install a new heating system and improve the efficiency of the overall plant. The capital to replace the system was not available and earlier attempts to include the work in other projects had fallen through due to expense and complications. Addressing these improvements through a guaranteed energy savings performance contract seemed the only viable option. This type of project would need to be fully funded through energy and operational savings with no capital contribution from the state or agency. To accomplish this, the team needed to find other savings opportunities to supplement natural gas savings attained by simply replacing the inefficient steam plant.
Although this facility faced the not so unique challenge of aging infrastructure, they also have a unique energy use profile. Being a convention center, load peaks do not follow a typical 9 to 5 schedule; instead events like the Kentucky State Fair drive large spikes in electricity use. These spikes result in minimum demand charge “ratchets” that penalize the customer’s electric bill for the next 11 months. Ultimately, it would be through this penalty that an opportunity would be developed to leverage demand reduction savings to fund a significant infrastructure project. This project included several innovative solutions and a range of facility improvements that were creatively developed to achieve the goal.
Unique Operations, Unique Energy Profile
One weekend in February the facility hosted a home and garden show, a beef cattle livestock show and auction, a Kentucky artisan market, a demolition derby and an all-star cheerleading competition. All events were held indoors in fully conditioned spaces. This represents a typical busy weekend at the Expo center. Throughout the year many large-scale multi-day events ranging from automotive and agricultural shows to volleyball and archery competitions are also held. Surrounding each event are setup and tear-down periods often longer in duration than the actual event where the site is very active but typically HVAC systems are idle or in energy saving setbacks.
Facility managers are energy conscious and ensure runtimes are limited to show times when exhibitors are contractually paying for the HVAC. Limited run hours would typically diminish the savings opportunity of any energy conservation measure. However, in the case of the KEC during facility-wide events, the energy intensity can be very high. HVAC makes up a large portion of the electric demand. In the case of the Kentucky State Fair, the largest and most energy intensive event each year in August, HVAC loads are the primary driver of power consumption. In this extreme instance each year, fair demand exceeds 12.0 MW on the hottest days, while the typical summer day is 2.5 MW. This load profile plays out multiple times each year for other shows at a reduced magnitude.
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