Is there a potential for heat loss in the winter after installing attic ventilation?

The potential for heat loss in the winter is more dependent on the amount of attic insulation than the attic ventilation system.

The potential for heat loss in the winter is more dependent on the amount of attic insulation than the attic ventilation system. An attic without attic insulation in the winter should be pretty close to outside temperature conditions because there is very little R-value in the roof deck. Adding ventilation should therefore only reduce the temperature a little. The reason an attic may be warm in the winter is because heat is escaping from the living space. In a poorly insulated house, the addition of an attic ventilation system could increase the amount of heat loss, but only because there is insufficient insulation. Furthermore, any possible heat losses in the winter are outweighed by the potential savings in summertime cooling with proper attic ventilation.