It is important to have proper ventilation so that the condition of the air in vents remains where it is supposed to, not compromising the condition of the rest of your home. This inefficiency will leave you uncomfortable and spending more money to try to condition the air quality of the space back to the way you prefer. One thing we do to manage this issue is properly insulate vents internally and externally. This photo shows a small vent which we will insulate inside and out to ensure there are no leaks.