Grand Forks, North Dakota
The project included the addition of 74,000 square feet of manufacturing space, office areas, lunch room, maintenance shops, 4100 square feet material storage freezer and truck loading docks to an existing facility.
The Cirrus design chiller plant was designed with two 400 ton air-cooled chillers and three 150 ton dry coolers. Each chiller has two 815 GPM, 20 hp operating/standby pumps. Each dry cooler has two 300 GPM, 10 hp operating/standby pumps. The building side loop is powered by two 1,425 GPM, 50 hp operating/standby pumps.
One of the primary owner requirements was redundancy. Each of the two chillers has three compressors with separate disconnects in lieu of a standard single-point connection. At maximum design load, the chillers have an extra 33% capacity such that one compressor can be down on each unit, but the required capacity is still met. Having three separate disconnects allows the replacement of a failed compressor without shutting down the entire unit. The chillers have the capability of operating down to 0 degrees F. The dry coolers operate through the rest of the winter as the building requires year-round cooling. At maximum design load, the compressor can be down on each unit, but the required capacity is still met.