As part of their Capital Engagement and Conservation Program the Toronto Community Housing Corporation is focused on reducing their energy consumption. One of their main initiatives is to reduce their utility costs. As part of this amazing initiative they were looking to replace their central HVAC system at 2950 Lawrence Ave. with a more efficient solution. Their previous system included (4) make-up air units and (20) central washroom exhaust fans.
Working with Efficiency Engineering, we designed four Aldes energy recovery ventilators (ERV’s) to handle both the ventilation air and washroom exhaust. Using the exhaust air from the building to preheat the outdoor air in the winter and precool the outdoor air in the summer we were able to recover and reduce the heating & cooling capacity required by ~620 MBH and ~12 tons, respectively.
We often get asked about exhausting washroom air through a central ERV system with the worry that some of the odour will pass through to the supply air. The amount of exhaust air transferred into the supply air through energy recovery technologies is known as the exhaust air transfer ratio (EATR). For this reason, we used the Aldes CE series units with flat plate heat exchangers which have an EATR of <0.7%, alleviating any concerns with cross contamination.
As a side note, all certified ERV/HRV technologies will have their recovery components listed on the AHRI directory showing their performance (including efficiency and EATR). The Aldes core performance used in the CE series can be found here under reference number 202350394 https://www.ahridirectory.org/Search/SearchHome?ReturnUrl=%2f.
The supply air from the ERV’s is going into living areas so it needs to have post heating and cooling. The customer wanted to avoid gas heating to minimize their carbon footprint. Using an LG Electronics air source heat pump, we provided the heating and cooling loads required. The LG units were connected to DX coils installed internal to Aldes CE units and integrated and controlled through an LG communication kit and electronic expansion valve mounted to the side of the Aldes unit. The impressive performance of the LG condensing unit being rated down to -22 deg. F gave the customer confidence that the supply air would be maintained at the desired temperatures for their occupants all year round.
O’Dell is extremely happy to have been part of this project which shows our ability to combine products from our diverse offering to provide our customers with energy efficient solutions.