Yes -- if the cold-air input is uncontrolled. In fact, uncontrolled cold-air drafts are the reason for dryness in older houses. Damper control of the cold-air intake (not the hot-air exhaust) will allow you to maintain whatever level of humidity you want.
If your furnace combustion air is provided by a large "L" shaped duct (horizontal from outside and then dropped down next to the furnace) as is often installed for gas furnaces, these uncontrolled ducts can cause a serious dry air problem in the house. The only code approved motorized dampers that interlock with the furnace to close these ducts off when they are not needed that I have found is called a Hoyme damper. (search the keyword "Combustion Air" for the title "WHAT IS A COMBUSTION FRESH AIR SUPPLY?")