CEE reveals $77K in annual energy-efficiency savings for historic Hotel Ivy
Luxury generally comes at a cost. But with CEE’s help, luxury can also come via cost savings.
Take the Hotel Ivy in the heart of downtown Minneapolis. As one of Starwood Hotels and Resorts’s exclusive Luxury Collection Hotels, it incorporates the city’s historic Ivy Tower — a striking, pyramidal structure originally built in 1930 for a religious congregation. Despite its original purpose, the tower was used mostly as an administration building and then eventually boarded up for over a decade until it was transformed into a luxury hotel in 2008. The Ivy Tower was added to the National Register of Historic Places in 1986.
In 2014, Hotel Ivy’s building owners turned to CEE’s Engineering Services team for some needed help. (Full case study here)
At the time, the hotel was battling higher-than-normal chilled water usage, especially during winter months. Big buildings often use chilled water to cool their air and equipment, especially when individual rooms (such as hotel rooms) need individual controls. The chilled water can be produced onsite or supplied by a vendor; in the Ivy’s case, it comes from NRG Energy Center Minneapolis. After an initial review, CEE’s engineers were optimistic that, with a little research, they would be able to identify savings opportunities to benefit all.
Over about four months in late 2014, CEE collected a variety of continuous data on all available mechanical equipment in the building. Over 5.2 million data points were collected across 600-plus channels from the building automation system and supplemental dataloggers. Complexities arose because some of the hotel’s central systems also serve separately owned condos. As feasible, however, CEE’s main focus stayed on the lodging, restaurant, spa/fitness, conference center, and garage functions of the hotel.
Using data-tracking, multiple site visits, and deep analysis through CEE’s proprietary TRAVIS software, CEE identified several major savings opportunities. A natural fit for a project like this, CEE also leveraged its One-Stop Efficiency Shop® program to identify some economical internal and external lighting efficiencies. CEE also found that the site’s free-cooling system — designed to capitalize on weather and reduce chilled water use during cooler months — was not functioning optimally, which resulted in less free cooling and more chilled water consumption than needed.
All told, CEE uncovered potential for the Ivy to make improvements that would save up to $77,000 annually, with improvements essentially paying for themselves within 3 years. Optimizing the building's chilled water system eliminated needs for simultaneous heating and cooling, which provided immediate savings. Other savings opportunities were found in adjusting airflow, improving hotel kitchen exhaust hoods and facility controls sequences, and incorporating energy-efficient lighting throughout the facility.
As part of its process, CEE helped bring together the building’s ownership parties, the controls contractor, and energy provider NRG Minneapolis to document the free-cooling system’s faults and CEE’s recommendations to maximize the instrumentation and onsite controls. This important step of documentation will help existing operators gauge building load and take action more quickly.
To most of us, luxury is synonymous with living in style and comfort. CEE’s Engineering Services aim to ensure that everyone living and working in the buildings we serve is provided with a setting that is effective, economical, and comfortable.
Download the full case study here