Air to Water Heat Pump Retrofit
Project type: Air to Water Heat Pump Retrofit and Upgrade
This building was a Montessori school until it became the new home of the Nanaimo Community Hospice Society. The NCHS converted it for use as offices, training, and counselling spaces.
The existing electric boiler was very expensive to operate, and there was no cooling in the building. Stage 3 Renewables designed and installed a new heating and cooling system that will cut the energy bills dramatically and provide comfortable temperatures throughout the year.
- Nordic Air to Water heat pump: The heart of the new mechanical system – this Canadian made heat pump heats and cools the building. It’s designed for cold climates, so it’s still highly efficient below 0˚C. The Nordic ATW series come with their new GEN2 control board: BACnet integration, data-logging, custom control and a data rich interface set this unit apart. Advanced defrost logic eliminates inefficient cycling, and the PWM fan is whisper quiet as it adjusts to the load. The commercial level capabilities of this Nordic 6 ton Air to Water Heat pump make a big difference to the installer and the building owner. Download Brochure
- Advanced Building Controller: The Tekmar 406 Heat Pump building controller intelligently coordinates this complex system. It utilizes outdoor reset to supply different water temperatures to the radiant floors, baseboards, and fan coils. During floor cooling operation, it uses humidity sensors and a variable speed injection pump to prevent floor condensation. This maximizes floor cooling potential during changing building conditions
- Networked Thermostats: The Tekmar tN2 programmable thermostats save energy and precisely control temperature. They communicate and share a setback schedule based on occupancy. Intelligent recovery ensures each zone is at the right temperature when people arrive in the morning. The adjustment band has been limited to prevent visitors from causing control issues.
- Hydronic Fan Coil Units: Multiaqua wall mounted fan coils provide supplemental heating and cooling. Their attractive design and quiet operation blend into the space nicely.
- Radiant Floor Cooling: The floors throughout the building can now do radiant base load floor cooling. It’s a silent, low-energy way to keep temperatures under control during warm weather. During floor cooling operation, the building controller uses humidity sensors and a variable speed injection pump to prevent floor condensation. This maximizes floor cooling capacity as building conditions change.
- Additional Zoning: During the renovation, the large open classrooms were divided up into smaller counselling offices, training rooms, and treatment spaces. The new floorplan required better temperature control, so we added temperature zones, actuators, and balancing.
This retrofit application of an Air to Water heat pump was a good design challenge. Stage 3 Renewables provided a complete mechanical package that is reliable and easy to operate. The new equipment integrated seamlessly into the building, and we were able to keep costs down by repurposing most of the existing distribution. The non-profit client now has comfortable spaces to do their important work, and their future heating bills will be much more affordable.