First National Bank

FIRST NATIONAL BANK

MANITOWOC, WISCONSIN

RENOVATION / REPLACEMENT

The focus of this project was to replace an existing 30 year old Trane 60 ton compressor condensing unit located on the roof with a Dunham-Bush HWSC 060 Small Hermetic Screw water cooled compressor condensing unit. We located the new unit in the basement mechanical room, near the air handling unit, and served the new unit with a cooling tower. This would eliminate years of mechanical transmission of noise and vibration throughout the building, reducing employee fatigue and increasing productivity

There were three predominant issues justifying this retrofit.

1) We would improve energy efficiency and system reliability.

2) We were replacing equipment which was approximately 30 years old.

3) We would eliminate the noise issue within the building caused by the type of reciprocating mechanical equipment located on the roof of the building over second floor offices and eliminate the refrigeration piping operational noise in the second floor ceiling which was amplified throughout the entire building.

SAMSA, Inc. provided a Dunham Bush HWSC 060 water-cooled screw compressor condensing unit. This unit would be extremely quiet, infinitely track building load and be water cooled to provide greatly improved efficiency over the existing air cooled equipment. We located the new screw condensing unit in the basement mechanical room next to the building air handling unit. We custom designed the unit to fit into an already tight mechanical room. Dunham-Bush custom built the unit and designed the Micro Processor control panel to SAMSA, Inc.'s specifications

The new custom built Dunham-Bush HWSC 060 Screw Condensing unit slid into the building through the existing louver opening on the west side of the mechanical room. This required removal of some ductwork, outside air intake louvers, and opening up the area well including excavating a small area away from it. Following entry of the equipment the area well was rebuilt and the Bank's drive through filled and patched. The AHU was cleaned including cooling and heating coils, outside air louvers and all ductwork cleaned and then replaced. The insulation was repaired and service of the AHU was restored within one working day.

The cooling tower is a Baltimore Air Coil model VTL 059 - Design capacity is 180 USGPM from 95 deg. F to 85 deg. F with 77.77 deg. F entering air wet bulb. This unit sits on the old compressor condenser frame with modifications and extra steel added. This unit was provided with custom vibration isolators and the fan motor is served by a Danfoss VLT 2800 variable frequency drive which will match the exact fan speed to the rejection cooling water requirements. This is an extremely quiet unit and will eliminate the past noise problems caused by reciprocating mechanical equipment.

All water treatment chemical and equipment is automated and independently pumped into the system weekly reducing the human factor to alternate chemical.

SAMSA, Inc. furnished and installed all necessary condenser water piping, valves, drain valves, chemical treatment access valves,(i.e. tower blow down), makeup water, pressure gauges and thermometers for a completely operational system.

Condenser water pipe was routed through the AHU room subfloor wall and followed up the back of the building and was connected to the tower sump from the suction side of condenser pump.

The condenser water piping was provided between the water-cooled condenser in the basement and the cooling tower on the roof. This piping was routed out through the area well next to the louver, up the side of the building, and run across the roof on pipe supports to the cooling tower. The piping also included make up water for the cooling tower. The cooling tower piping up the side of the building was enclosed by an architectural enclosure. The enclosure was coordinated with the piping supports so that enclosure framing could be attached to the pipe support system. Enclosure system was installed to match the building glazing and door entry or vestibule trim.

Insulation: All refrigeration piping was insulated with 3/4 inch armaflex insulation to include: valves flanges and any equipment that could sweat. Insulation exposed to outdoor elements was painted.

Salvage: Removal of old Trane condensing unit located on roof was disposed of in accordance with all State and Federal regulations. Refrigerant was recovered into DOT approved recovery cylinders and shipped to a reclamation facility. System oil was withdrawn from the compressor oil sump and disposed of as a hazardous waste.

Start up service and warranty: SAMSA, Inc. provided start up and warranty service on all new equipment. All manufacturers supplied one year parts warranty on their equipment.

Project Management:.SAMSA, Inc. managed all facets of this project with respect to the installation of the new system. SAMSA, Inc. also directed all subcontractors to ensure a sound installation.

SAMSA, Inc. supplied all subcontractors with necessary diagrams and information required for the installation of equipment.

SAMSA, Inc. is the contractor for your next retrofit. When the heat is on and the system fails, no other performs with just a handshake like SAMSA, Inc.