Supply ventilation

Furnace was a Trane forced warm air manufactured in 1997. The furnace has a humidifier.

Return duct has a supply ventilation from the outdoors.

My question is in a cold climate like Cleveland is it really needed?

What advantages and disadvantages would this have. It does have a damper that can be closed or opened. There was no motorized damper.

Home is a 2 story colonial about 2500 sq. ft.

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