Source: https://www.zehnderamerica.com/why-ventilation-should-be-separate-from-heating-and-cooling-systems/

We often get asked if our HRVs and ERVs can be coupled with a building’s heating and cooling system. It makes sense, right? If there is already a system of ducts in place for the furnace and or air conditioning system, why have a second parallel system? While it may be less expensive to combine the two systems together and it may save a little space, the project is better served by having independent systems that each focus on their task. This blog entry will explain the reasoning why. Note that for simplicity in writing I will use “HRV” to represent either an HRV or ERV system and “air handler” to represent a furnace, air conditioning system, heat pump etc – whatever forced-air system is meeting the heating and cooling needs of the building.