When the Nanaimo Community Hospice Society contacted British Columbia company Stage 3 Renewables to consult on ways to lower their heating and cooling bills, they didn’t know they would end up with one of the most advanced heating systems available in Canada.
The NCHS had moved into the building, which originally housed a Montessori school, and wanted to upgrade the existing electric boiler while adding air conditioning to keep their residents comfortable year round.
Stage 3 Renewables chose a Nordic air to water heat pump for this project and designed the new mechanical system to compliment the ATW Series. They chose this heat pump because the unit’s Canadian design meant it would perform well in colder temperatures, and the fully reversing heat pump could provide chilled water for air conditioning.
The ATW Series has a built-in Gen2 control board with BACnet capability, which allowed it to integrate seamlessly with the Tekmar 406 heat pump controller the installers used to coordinate the system and take advantage of the integrated outdoor reset control for maximum efficiency. The outdoor reset controller varies the output temperature of the heat pump to the different radiant floors, hot water baseboards, and fan coils so that each zone can be individually satisfied.
Also included in this system was smart thermostats, programmed to vary the building temperature depending on occupancy. For example, when staff left part of the building for the evening, the thermostat in that area is programmed to lower the temperature, and then raise it before staff returns the next morning.
Integrated Air Conditioning
The air to water heat pump was also chosen because its fully reversing system allows for heating and cooling in a single unit, eliminating the need to install an additional air conditioner. Air conditioning was achieved on this project through a combination of Multiaqua hydronic fan coil units, which were mounted on the walls of rooms where their low profile and quiet operation allowed for unobtrusive operation, and radiant floor cooling.
The radiant floor cooling was used for base load cooling, where the building controller uses humidity sensors and a variable control injection pump to prevent condensation.
Upgraded Mechanical Systems
Stage 3 Renewables was able to work with most of the existing distribution systems, and even maintained the existing electric boiler as backup heat. In some areas where changes needed to be made, this British Columbia heat pump installer upgraded systems as necessary.
The NCHS required a system that would operate silently both inside and outside the building. The radiant in-floor system is ideal for quiet operation, and the indoor unit can be located away from living areas. Outside the building, the outdoor portion of the ATW Series operates at a low volume, providing residents with a quiet and tranquil outdoor space.