Case Study: Corporate Oaks II, Chantilly, VA

The challenge with this project was to minimize downtime for the occupied building, reuse the existing roof curb and ductwork/utility connections, and upgrade the electrical wiring from aluminum to copper.

DMR Associates Case Study: Corporate Oaks II, Chantilly, VA.

Owner: H/F Water Dragon, LLC

Management: Metro Management Services, LLC

Contractor: Fidelity Mechanical Services

Summary: The project started on a Thursday night, and by the following Thursday, the new unit was installed and fully operational.

Watch Video: Time lapse of Corporate Oaks II installation

DMR Time Lapse Video 2021


Background

Built in 1987, the original 277-Ton, 85,000 CFM Mammoth Custom Penthouse supplied by DMR needed replacement. The challenge was to minimize downtime for the occupied building, reuse the existing roof curb and ductwork/utility connections, and upgrade the electrical wiring from aluminum to copper.

Project Schedule:

Thursday Night: Prep the unit for removal: evacuate refrigerant charge; disconnect utilities and supply duct connection; cut wiring and piping between unit sections, prepare sections for separation/removal.

Friday: Remove old unit and rig new unit, four sections each. Replace main electrical wiring.

Saturday: Prep new unit for start-up: connect new electrical; make factory pre-engineered electrical/control connections between unit sections; connect BMS communication wiring; perform pre-startup.

Sunday: Perform factory unit controls and fans startup for economizer operation and BMS interface control.

Monday: Unit operating in economizer mode. Begin connecting refrigerant piping across sections, evacuation, charging. Water treatment installed.

Tuesday:Two of four refrigerant circuits operating.

Wednesday: Final two refrigerant circuits operating.

Thursday Morning: Fully Operational.

Enhanced Features of New Unit:

Double Wall Thermal Break Cabinet, Embossed Aluminum Exterior, Aluminum Interior

VFD Supply Fan Control, One VFD per Fan

Exhaust Fans with Variable Speed EC Motors

304 Stainless Steel Coil Casings and IAQ Drain Pan

Updated Evaporative Condenser Design with Stainless Construction, R-410A Refrigerant, VFD Head Pressure Control

Change from (3) Screw Compressors, (3) Circuits to (4) Tandem Scroll Compressors, (4) Circuits

65 KIAC SCCR

Case Study Old and New Units

Contact DMR for more information on how our team can help with your next retrofit and replacement project.

About Mammoth

For more than 80 years, the Mammoth brand, from Nortek Global HVAC, has been creating a comfortable indoor environment for both industrial and commercial customers around the world. From factory-packaged rooftop systems to prefabricated mechanical equipment rooms, Mammoth custom commercial equipment improves air quality and reduces operating costs.