MEP designed a complete retrofit of the existing heating, ventilation, and air conditioning system. The existing variable air volume system with hot water reheat and direct expansion cooling will be replaced with a geothermal chilled water plant with ice storage. The geothermal system will provide chilled water for cooling by utilizing ice storage that will be made during off-peak hours. Design calculations estimate that this system will reduce overall energy consumption by 15% and reduce costs by 30%. Key design features include modular reverse cycle chillers and variable speed pumping to all loops including the geothermal well field. The building received an ENERGY STARÂ® Performance Rating of 93 out of 100 and qualifies for LEED Silver certification.
Solar Heating Systems
MEP provided design services for the addition of a solar heating system for the â€œEnergy Renovationâ€ at the Minnesota Valley National Wildlife Refuge. MEP designed a solar thermal heating system with 1,000 SF of collector located on the south face of the Visitor Center roof.
There are twenty-four panels connected to approximately 1,000 gallons of water for thermal storage. The system is tied into the buildings heating system and is utilized as the first stage of heating. The panels are designed to drain when heating is not needed or not available to prevent potential freezing issues and to eliminate the need for adding heat rejection equipment.
MEP provided Fundamental Commissioning Services for the new mechanical systems in the existing building. The systems included water-to- water heat pumps, energy recovery air distribution systems, hot water boilers, ice storage, as well as hot and chilled water primary/secondary distribution systems.