The Role of Microturbines in Hotel HVAC Systems
HVAC (heating, ventilation, and air conditioning) systems have a greater impact on guest comfort than any other building system. While guests won’t tolerate a stuffy room, hotel management must balance the realities of high operating costs or potentially dissatisfied and uncomfortable customers. Taking action to upgrade HVAC systems in today’s hotels and lodging facilities can help cut energy costs while improving guest comfort.
HVAC upgrades provide several benefits for hotel operations, including enhanced guest comfort, decreased energy consumption, higher reliability, longer equipment life, and overall cost reduction. Additionally, HVAC systems provide many options for increasing energy efficiency – programmable thermostats, room occupancy sensors, variable speed blowers, low pressure-drop air filters, and high efficiency chillers and boilers. The most energy efficient systems are combined heat and power (CHP) and combined cooling, heating, and power (CCHP) systems that combine an electric generator with a heating or heating and cooling system that uses the generator’s exhaust heat to provide heating or cooling instead of using more gas or electricity to drive these systems. This results in extremely high fuel efficiencies, which drives down costs and reduces carbon intensity. Best of all, these systems can be retrofitted easily, avoiding occupancy reductions and impacts to operations.
While most HVAC upgrades can be justified by improved reliability and increased guest comfort advantages alone, more efficient HVAC systems can reduce enough costs to completely pay for the upgrade, and then continue to provide significant annual savings over time. In many cases, return on investment (ROI) of HVAC system upgrades outperforms other property upgrades and improvements.
Customer Success Story: Logan Hotel Philadelphia
As a five-star luxury hotel in downtown Philadelphia, the Logan Philadelphia Hotel (formerly Four Seasons Hotel
Philadelphia) uses a tremendous amount of energy each day. From cooking, heating, lighting, laundry, showers, swimming pools, and more, the demand for steam and local electricity was high and costly.
Aiming to gain control of energy costs and reduce the hotel’s greenhouse gas emissions, the management of this opulent, 391-room icon turned to E-Finity Distributed Generation to install a natural gas-fueled system that could generate electrical and thermal power, onsite, for the hotel’s own use.
Installed in 2009, the combined heat and power (CHP) system features three Capstone C65 ICHP natural-gas microturbines installed atop the eight-story hotel’s roof, easily fitting in a 37-square-meter space. The system generates 195kW of electrical power, which covers 30 percent of the hotel’s overall electricity needs. During the generation process, exhaust heat from the microturbines is captured and used to heat water for laundry and other hotel operations. In fact, the energy-efficient CHP application provides 100 percent of the building’s day-to-day domestic hot water and 15 percent of its heating needs.
Aesthetically, the system is quiet and takes up minimal space, a key reason the C65 microturbines were selected over reciprocating technology. With a noise output of only 65 decibels at 10 meters, the microturbines do not disturb guests in the Presidential Suite directly below—or in the nearby rooftop lounge that was installed in 2016. Further, reciprocating engines’ energy efficiency is often less than 30 percent compared to a Capstone C65 microturbine in a CHP application, which boasts energy efficiencies greater than 80 percent.
To date, all three units have logged more than 85,000 hours of continuous run, representing 99.8% uptime. The overall ROI for the system was 4.2 years thanks to considerable cost savings and efficiency. Because the hotel buys natural gas from a third-party, it can shop around for the best rate. Doing so amounts to a 30 percent cost reduction over power purchased from the utility. The rooftop microturbines, which sit amid prime metropolitan real estate, are also ultra-low in emissions (< 9 ppmv NOx at 15% O2), making this onsite power generation system a clean-and-green, environmentally friendly option. Thanks to the system, 425 metric tons of CO2 emissions are avoided each year—the equivalent of removing 70 cars from the road.
The hotel has received recognition for its environmental achievements by being named one of TripAdvisor’s Green Leaders Partners (bronze level award) and in its ranking as #11 Green Hotel in Philadelphia, as well as being a featured case study in ASHRAE’s Combined Heat and Power Design Guide.
Capstone is exhibiting at AHR Expo Feb 6-8 at the World Congress Center in Atlanta, GA. The AHR Expo is the world's largest HVACR event, attracting the most comprehensive gathering of industry professionals from around the globe each year. Stop by booth B4575 and speak to a representative about our combined heat and power (CHP) systems that can reach efficiencies of more than 80%.