Like an erv a ventilating dehumidifier introduces fresh air from outside your home filters it and removes indoor air for consistent circulation.
Air exchanger or dehumidifier.
Try the air exchanger.
If the smell occurred right after you installed the exchanger i would suspect the exchanger either smells or is pulling air from an area that smells.
The supply air temperature from the sd 12 is significantly closer to the return air temperature than a typical ac system but it is still a lower temperature than the return air temperature.
Dehumidification should be done by a dehumidifier and fresh air exchange should be done by an air to air exchanger hrv erv etc.
Call your contractor and have him check it out.
Since it is a basement the dehumidifier is not a bad thing.
Ac dehumidifier also has a condenser evaporator and metering device to gauge the air in the room.
I would recommend not running the dehumidifier in the winter.
The heat exchanger is not 100 effective so there is some sensible cooling from the sd 12 in addition to the dehumidification.
Cooling dehumidifier heat exchanger main features finned tube heat exchanger type for dehumidification of air by means of condensation by using ice water or other cooling media flowing through the heat exchanger tubes followed by a demister and re heater steam or hot water to heat up the air above the dew point.
In a ventilation dehumidifier equipped with a heat pump the heat pump functions both as a dehumidifier and a dedicated heat pump.
In our climate zone the best equipment for ventilating your home and dehumidifying indoor air is a whole house dehumidifier with positive pressure from fresh outdoor air.
Indoor air contamination continues to rise with time and oxygen levels continue to fall a fresh air exchange is crucial to good long term health.
The energy from the warm humid air in the swimming pool room is recovered in the heat recovery section normally in a plate heat exchanger.
As the other poster said the fresh air ventilation has nothing to do with dehumidification.
You will want to run a dehumidifier in the summer because if you bring air in from outside it will contain humidity possibly more than what is already in the basement.