In December of 1998, the 170-unit St. Petersburg North La Quinta® Inn in St. Petersburg, FL, replaced its three aging water heating systems. The previous systems were more than 10 years old, and wisdom dictated replacing them before they failed and created an emergency which would leave guests high and dry.

Since La Quinta has been purchasing A.O. Smith water heaters for the past five years for its entire chain of more than 230 inns and 70 inns and suites, the selection of A.O. Smith as the manufacturer of the replacement equipment was a natural choice. For this particular inn, the chain specified three Cyclone XHE® BTH-150, 150,000 Btu units. The Cyclone offers 94% thermal efficiency and La Quinta hoped to take advantage of the changeout to reduce its water heating costs.

Installation Challenges Abound

Florida Boiler Sales & Service, Inc. (Tampa, FL) installed the units and faced a unique challenge during the installation: a remarkably narrow mechanical room with limited space to maneuver in, along with the need to continue providing hot water to residents of the inn during changeover. Providing uninterrupted hot water is a standard requirement during installation, and under normal circumstances satisfying this requirement is not a problem. The new equipment is usually installed in the mechanical room and put on-line before the old equipment is even removed to ensure that the hot water service continues without any interruptions. However, due to the fact that the mechanical room at the inn was only 3 ft wide, conducting the installation in this manner was not an option.

The situation required the removal of all the old equipment before the new units could be brought into the room and put on-line, which would leave the inn without hot water during that phase of the installation. The solution Florida Boiler came up with, according to project leader Denny Bailey, was to preplumb all the new heaters, run the necessary electrical conduit, and perform any additional tasks in advance of the changeover. Then, at a time predetermined by the inn's management, the crew pulled all the old equipment out of the mechanical room and moved in the first Cyclone. The unit was placed, the plumbing and venting was completed, and the unit was then started up. This single Cyclone XHE carried the entire hot water demand of the 170-unit inn until the installation of the additional two units was completed, about four hours later.

"This is when a product's track record for quick, reliable service and immediate starting capability really pays off," says Bailey.

Installation of the three Cyclone units in the small space was itself not a problem. The units require zero clearance and vent either vertically or through sidewalls, making them ideal for installation in limited areas. For the La Quinta Inn, the installers used an existing pipe chase built for the previous equipment to vent the Cyclones, eliminating the need to make any new penetrations - another time and effort savings.

Cost Savings

At the same time that the Cyclone XHE water heating units were being installed, Kim Ackles, La Quinta's director of energy and engineering, made a change in gas suppliers that produced additional savings. The total gas cost savings in 1999 came to 27% of the previous year's total gas costs, which equals roughly $3,600. Ackles calculates that 10% of the total savings is attributable to switching gas suppliers, leaving the remaining 17% of the savings as a direct result of installing the new, more efficient A.O. Smith Cyclone XHE water heaters.

The heaters boast 94% thermal efficiency, due primarily to the design. Gas and intake air are mixed by being swirled in opposite circular directions, much like a cyclone, producing a nearly perfect mix of the two for maximum combustion efficiency. The resulting flame is directed to a submerged combustion chamber, and hot fuel gases are forced through the unit's heat exchanger coil. The shape of the coil, together with the force behind the gases, provided an extra high heat transfer rate, which translates into higher thermal efficiency.

The three units have been operating for more than a year and, according to Ackles who keeps a close watch over the performance at all of the La Quinta Inns, the Cyclones have continued to provide fuel cost savings and a reliable hot water supply even during the busy tourist season. ES