Cramped Mechanical Room Spurs Switch to Multi-Unit Tankless Water Heating System for 130-Room Hotel Project

When the original boiler spec proves unworkable, hotel ownership switches to a 93%-efficient condensing tankless solution to save both space and fuel costs. With inputs up to 3.4 million BTU per hour, 17-unit system uses innovative common-venting approach to minimize exterior wall penetrations.


The space-saving advantages of tankless water heating recently came into critical play at a 130-room hotel renovation project in Florence, Alabama. The original specification for the Florence Residence Inn by Marriott called for a pair of 750-gallon, 750,000 BTU per hour (BTU/h) boilers, each measuring roughly five feet by 12 feet. The mechanical room where they were to be squeezed into could accommodate both pieces of equipment, but with just a few inches of clearance between each unit and the surrounding walls. Contractor Anthony Crouch, owner of Crouch & Sons Plumbing LLC in Florence, reviewed the original specification with his plumbing distributor, the Tallman Company, and quickly concluded that the installation was all but unworkable.


Jason Veal, whose company distributes tankless water heaters made by Noritz America,  immediately saw a fit for tankless because of its space-saving benefits.  A multi-unit system would be required to meet all of the hotel’s hot-water needs, especially during peak periods. These units are not only much smaller than the two specified boilers, but because they would also wall-hung, there would also be more room for service work. Furthermore, if one unit had to be shut down, the others would still operate as usual. Guests would see no interruption in service.


Location: Marriott Residence Inn
City: Florence, AL
Max. occupancy: 130 guest rooms 


Location: Indoorinstallation, mechanical room
Applications: 130 showers, tubs, sinks, dining area and laundry room
Vent set-up: Fan- assisted, common vent system by Exhausto Inc.




Noritz units: 17 Noritz NCC199-SV
Noritz accessories: Isolator valves and System Controllers
Fuel type: Natural gas
Gas consumption: Max. 3.4 Million BTU/H
Thermal Efficiency: 93%
Flow rate performance: 0.5 – 115.6 GPM
Temperature settings: 100-180 degree F
Warranty: 5 years on heat exchanger and parts (non-prorated)






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