How Do I Reduce or Eliminate Convection?
Window convection is a process often misunderstood by homeowners. Many people simply think it is the same thing as drafty windows. But window drafts and window convection are two different things. Window drafts are basically air flow in and out of the home through closed window spaces. Drafty windows are caused by many different things. Poor or cracked caulk jobs can create a draft, as can faulty or missing weather stripping. Even simply failing to lock a window when it is shut can prevent it from sealing properly and cause a leak. This is especially true in double hung and slider windows, which already do not tend to seal as well as hinged windows with compression seals.
Convection Differs from Window Drafts
But window convection is different. In fact, it can occur in a window that has no air leaks at all. Window convection is a process by which warm air flows up against the cooler surface of a window and forces colder air away from the surface. That colder air in turn sinks toward the ground and more warm air get moving toward the window surface. The resulting air movement cycle can feel a lot like a draft.
How to Combat Window Convection
To reduce the presence or frequency of window convection in your home, there are some things you can do. Leave your blinds or curtain slightly open to encourage warm air reach the glass. Promote a warmer glass surface and that cycle will not be as pronounced. Make sure heat registers are not blocked by tables, couches, or other furniture. Get good air flow and equalize air temperatures throughout the room. Of course, window replacement also helps, as reduced heat loss makes that inside pane temperature closer to the air temperature.