Overcoming Copper Thieves, Mold and Deadly Bacteria

January 26th, 2012 → 7:35 pm @ // No Comments

Plagued with Legionella bacteria infestation, copper looting and unabated mold growth, the 97-room Cortina Inn here was in need of an overhaul.  Among the needs: an entire heating and domestic water supply makeover. Originally constructed in 1968 with additions in the following decades, the Cortina Inn tested positive for Legionella bacteria in 2008. The hotel sat vacant for two years before the current owner purchased it in a badly neglected state. While abandoned, copper thieves stole all of the laerge hot water mains. With every puncture to the service lines, water at 50 PSI soaked the entire structure. This led to pervasive mold growth; times were bleak for the once-majestic Cortina Inn.

Multi-faceted retrofit

“The renovation was an extensive project for everyone involved, but for us, there were two main goals,” said Steve Ellerin, president of Excel Plumbing & Heating. “First, restore the entire plumbing and heating systems, and then mitigate the Legionella bacteria problem. The owner of the hotel didn’t want a full-blown engineering project, so, we sttled on an open-book, time and materials contract.”

Based in Rutland, Vt., the 11-person Excel crew has focused on residential and light commercial work since 1990.

Two huge oil-fired cast iron sectional boilers were still used for space heating in ’08, before the hotel closed its doors. The boilers were installed in 1987 when the last building addition was completed. They were connected to small hydronic coils within individual PTAC units in each of the guest rooms. For the domestic hot water, two 650,000 Btuh gas boilers heated 300 gal. indirect storage tanks.

One of the early tasks was to replace the stolen 2 1/2-in. hot water mains. Then, Excel crews focused their attention on installing smaller piping components and all bathroom fixtures.

As work at Cortina Inn progressed, all four boilers and the indirect tanks were pulled out of the mechanical room and replaced with new equipment. In their place, five 100-gal., 199,000 Btuh Bradford White eF water heaters with a thermal efficiency up to 99.1% were installed to provide domestic hot water for the building. The units werre selected because they were big enough to handle the load but small enough to avoid needing an ASME boiler stamp.

“By avoiding larger units, the hotel owner and maintenance crews have one less thing on their already-full plate,” added Ellerin. “The new gas fired water heaters are infinitely more efficient abd dependable than the original units.”

Next to the water heaters in the mechanical room are two gas-fired, low NOx Laars NeoTherm boilers. The 95% efficient, modulating-condensing boilers are twinned for lead-lag sequencing, providing a combined 400,000 Btuh for the five new, common area fan coil  systems.

Four 7 1/2-ton units were salvage before the remodel, and reinstalled.

“Two new units were also installed in the lobby and other common areas,” said Ellerin. “One was a roof-top model that we actually installed on a concrete pad on the ground, and the other was a 7 1/2-ton air handler with a hot water coil.”

The mechanical room is centrally located within the 500-ft.  hotel. One main goes east, the other west, each equipped with a Taco 2400 circulator.

“We chose the 2400 because it comes in many different configurations,” said Ellerin. “We were able to order the pump to precisely meet our flow rate and head loss.”

Excel used a primary/secondary piping configuration. Ellerin set up the two boilers to inject heat into a primary distribution supply and return main with with each fan coil being served from secondary bridge piping.

Two closely spaced T’s and a Taco 007 circulator were used to distribute water to each air handler or cabinet heater. This allowed for the use of much smaller, more energy efficient pumps. In this way, each pump was merely required to meet the flow specifications of each individual fan coil.

To provide space heat for the guest rooms, the old, R-22 PTAC units in each room were replaced with propane-fired, direct-vent PTACs. The direct-vent units have a heat input of 14,000 Btuh each. Many of the rooms and common area also have propane fireplaces.

Thermal Air Conditioning, as always, thanks you for reading.

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