Delivering Quiet, Energy-Effective Comfort
During summer 2006, the Woodbury Corporation designed a 51-room addition to this 102-room, Residence Inn by Marriott extended-stay hotel 15 miles south of Salt Lake City, Utah. A leading commercial real estate firm since 1919, Woodbury owns and operates eight hotel properties in the Salt Lake metro area, with a ninth property currently under construction. For the HVAC needs in the new addition, Woodbury Corporation contacted Gary Wadsworth, senior account executive, Refrigeration Supplies Distributor (RSD), Salt Lake City. RSD is the oldest (1907) and largest refrigeration parts and equipment wholesaler in the Western United States.Silent, Rapid Response System Required
“For our new 51-room expansion, we required a reliable, quiet, energy-efficient and cost-effective HVAC system,” said Guy Woodbury, vice president of hospitality, Woodbury Corporation. “In the hotel business today, we guarantee our guests’ satisfaction. An HVAC system that doesn’t promptly deliver cooling and heating to guests’ liking can jeopardize a lot of revenue. For example, in our expansion, our rooms with a southern exposure can get very warm in the winter, while the rooms on the north can be freezing. We needed a system that could readily provide simultaneous cooling and heating to the ever-changing temperatures of both zones.”
Woodbury said that since Mitsubishi Electric Cooling and Heating Solutions, Suwanee, Ga., introduced Variable Refrigerant Flow (VRF) zoning technology, he’d been talking to Wadsworth about its application at his hotel properties. “We both knew the existing system in our original Marriott building could be improved, and decided this was a perfect opportunity to test this innovative class of air conditioning and heating.”
Based on 20 years of successful Mitsubishi Electric system installations in and around Salt Lake City, Ray Wilde, Dale R. Wilde Company, Salt Lake City, specified the R2-Series, part of the line of VRF systems by Mitsubishi Electric.
“This simultaneous cooling and heating two-pipe system with INVERTER-compressor technology was ideal for the Marriott addition,” said Wilde. “I specified this system because it could easily handle the precise cooling and heating load requirements of the new addition. What’s more, I knew Woodbury would value the quietness of the indoor and outdoor units, the overall energy savings, the advanced controls network and the flexible, ducted indoor units that fit the designed space perfectly.”
The Next Steps: A $27,000 Rebate
At this point, Woodbury assigned Dan Maynard, chief of hotel engineering, to learn more about the VRF zoning system design and how it could be applied at the Residence Inn. Wadsworth invited Maynard and Deserae Wilde, HVAC design engineer, to a Mitsubishi Electric Diamond Designer™ training seminar.
“The design training class was a great learning experience,” said Maynard. “It provided us with a hands-on opportunity to see how everything works together—the two-pipe VRF systems, INVERTER technology, the advanced controls network, modular design flexibility, easy installation and maintenance.”
The stick frame, three-story structure took one year to complete. Wadsworth described the R2-Series installation as trouble-free and uncomplicated. “Working under my direction, with savvy engineering guidance from Ray Wilde, Interwest Mechanical completed the installation of basic piping, wiring and ducted indoor units in less than six months. Because this is a two-pipe system, the installation was less expensive than a complicated three-pipe system and required fewer days to complete. Woodbury was so pleased with the outcome they plan to remodel their downtown Salt Lake City Radisson® Inn with the Mitsubishi Electric R2-Series,” said Wadsworth.
Once the R2-Series was installed and running successfully, Maynard was impressed not only by the response time and level of temperature and zone control, but also by the INVERTER-driven compressor that performs at the minimum energy level necessary to provide comfort in all zones of the hotel. “Because of the R2-Series’ design, we were given an energy savings rebate of $27,000 from our electrical supplier, Pacific Power,” said Maynard
Great Solution for Hotel Properties
“Mitsubishi Electric VRF zoning systems are able to satisfy a significantly higher building load by efficiently distributing the capacity of the indoor and outdoor units while using much less energy,” said Wadsworth. “And, they are extremely quiet (as low as 25 dB(A) for the indoor units and 61 dB(A) for the outdoor units).”
Wadsworth further explained that the total applied capacity of the R2-Series’ systems indoor units can be up to 150 percent of the capacity of the outdoor unit by taking advantage of load diversity and simultaneous cooling/heating operations. Especially for hotel owners and property managers, these combined benefits mean enhanced comfort, effective use of energy and quiet operations for sound-sensitive hotel rooms.
In addition to VRF zoning systems, Mitsubishi Electric has been known for its popular and proven split-ductless systems for more than 25 years. Wadsworth explained, “Split-ductless systems provide great spot cooling and heating solutions. We’ve specified them for the kitchens, computer, television, telephony and high-speed Internet rooms at Woodbury’s latest hotel property, the Hilton Garden Inn®, under construction in Sandy, Utah.
Total Control from Remote Laptop
“I now have remote access to the controls network at the Residence Inn,” Maynard said. “The network connects multiple VRF systems via a Local Area Network (LAN) to its exclusive TG-2000™ integrated systems software. Using a Web browser interface, I can access all remote controllers at the Residence Inn from my laptop at home—this is a huge benefit and convenience for hospitality engineers because it allows us to troubleshoot without being on site.”
