Evergreen North Apartments
Property Details: Located in Kalamazoo, it is a 165 unit, low income, senior housing facility
Products Installed:
- (8) Robur 95 MBH Natural gas powered absorption heat pumps (121% thermal efficiency for hydronic heating and cooling)
- (6) Robur Heat recovery chillers
- (1) Raypak XTherm 1,500 MBH Condensing Natural Gas fired boiler (96% thermal efficiency)
- (2) ECM Motor (Variable speed building pumps, 93% efficient)
- (1) Magnetic strainer/filter
Contractor: William E. Walter
Their HVAC system was scheduled for a 2017 boiler and chiller replacement project based on a site inspection and equipment review. Performance Engineering Group reviewed the systems connected to the boilers and found that they were candidates for gas fired heat pumps, due to the low water temperature requirements of the fan coil units in each apartment. Ventilation air is provided to the hallways by a separate gas fired make-up air unit located on the building roof. In late March, 2017, as the project was being scheduled for construction, the back-up chiller failed and caused the implementation plan to be accelerated. The lead time of the replacement cooling equipment became a driver of the decision to replace all the boilers and both failed chillers using the natural gas powered heat pumps which can provide either hot or chilled water. The replacement system was providing cooling by the 1st of May in 2017. Year over year total electrical savings are 140,000 kWh, almost 40% of total electric usage, and peak demand was reduced from 87 kWh to 40 kWh, or 54%.
