Marriott Intl. Inc. will soon have a LEED pre-certified hotel prototype, available from April 2010, for its Courtyard brand hotels. This project was started at the end of 2007 when Marriott joined the USGBC. The prototype, which will guarantee the basic U.S. Green Building Council LEED certification level (owners can achieve a higher certification, depending on the site) will reduce a hotel’s energy and water consumption by up to 25%, and save owners approximately $100,000 and six months in design time.

Scheduled to open this summer, the Courtyard Settler’s Ridge in Pittsburgh, Penn., will be the first hotel built, based on the pre-certified LEED hotel prototype concept.

A heat recovery system with a roof top air handling unit and a guestroom bath exhaust system are incorporated in this hotel. During the past few years, a guestroom bath exhaust system in a horizontal configuration with a constant draw of 30 cfm, produced by main exhaust fans at both ends of the corridors, was utilized.  But in this project, an additional exhaust was achieved by installing individual, locally switched, exhaust fans in each guestroom bathroom, providing an additional draw of 65 to 80 cfm.

Introduction of the heat recovery wheel into the outside air supply system requires mechanically balancing the cfm of supply and exhausting air to meet ASHRAE 62.1 outside air minimum ventilation requirements for LEED pre-requisites. Therefore, the size of exhaust duct work was increased and balancing louvers were added as the individually switch exhaust fans in each room were eliminated. 

The public areas in the hotel are controlled by thermostats and are conditioned with five fan coil units and three air handling units suspended from the second floor deck, and supplemental heat is provided by two electric horizontal heating units in the main mechanical and electrical rooms, and electric wall heaters in entrance vestibules.   

The Energy Efficient features of the HVAC system are two 100% dedicated outside air system roof top units equipped with an energy recovery wheel that will reclaim heat energy from the guestroom bathrooms, and energy efficient fans in the units that provide additional energy savings when compared to the minimum requirements for ASHRAE 90.1. 

Energy saved by the HVAC system for space heating was about 72% and 30% for space cooling, interior fans contributed about 17% energy savings, but LEED energy calculations are based on the overall building and site energy use in dollars, higher U-values for glass, exterior insulation and roof insulation helped play a role in the overall energy savings for the HVAC systems. The overall building energy savings was about 19% kWh, and the overall LEED energy savings in dollars was about 24%.

Water conserving features in the hotel include 1.28 GPM water closets by Kohler, 1.5 GPM lavatory faucets by Simmons, and 2.0 GPM shower heads by Speakman, which meet the 25% water savings in LEED requirements. Based on the LEED calculations, the annual water savings will be estimated as 319,275 gallons.

Marriott plans to introduce similar green hotel prototypes this year for its Fairfield Inn, Residence Inn, SpringHill Suites and TownePlace Suites brands.