Draft vs. Convection 

Drafty Windows

Windows can seem “drafty” for a variety of reasons:

• Cracked caulk
• Improper window locking
• Interlocks that are not lined up to seal properly
• Damaged or missing weather stripping
• Poor insulation within the interior walls.   

These types of problems are easy to remedy, however windows may seem “drafty” for another reason:  a process in physics known as “Convection”. 

Convection

Convection occurs when air gives up its heat to the colder glass and sinks to the floor.  This movement sucks new, warmer air toward the glass that is simultaneously cooled, creating air movement.  What you are actually experiencing is the process of warm air forcing colder air to move due to differing density properties.  Heated air circulates through the home.  When it reaches window glass it effectively pushes the existing air off the glass.  This movement can be perceived as a “draft”. 

Try this easy experiment as an example of how convection works:

• Fill a glass with ice and water.  Let it stand for about ten minutes.  When you return, without touching the glass, place your hands around it.  You will feel cold air on your hands as warm air pushes it away from the glass surface.

Convection is actually proof that your new Comfort Windows are energy efficient and working at peak performance. 

Tips to Reduce Convection

• Leave your blinds or window treatments open ¼ of an inch so that heated air can reach the glass.
• Make sure that your heat registers are not obstructed by couches or other furnishings.

A Comfort customer has the option to choose either of these:

 A Retrofit installation is the industry standard and is typically where the operating sash vents of an existing window are removed, but the existing window main frame remains intact. The new custom sized window, along with its new main frame and sashes, is then installed into the existing main frame. There is virtually no disturbance to any existing trim or wall area. Most of the time, a wood stop will be applied on the interior perimeter of the new window and the existing exterior trim is wrapped with formed aluminum trim, caulked and sealed, maintenance free!  Note: Glass sizes of the new window will be slightly smaller than the original window.

 A Rough Opening installation is where the entire window, main frame and sashes are removed back to the original wall studs. No trace of the original window will remain. The opening is then reconstructed with the new window installed, and includes a new wood extension jamb, new interior perimeter stops, new interior ranch or colonial style wood trim, a new interior sill or stool if required, new exterior stops and exterior wood casing with a sill, and the complete new wood exterior is then wrapped with new formed aluminum trim, caulked and sealed, maintenance free!

Moisture goes away quickly as the morning sun makes things warmer. Exterior moisture rarely forms in the colder, less humid winter months.

A single pane glass window will be much less likely to ever show exterior condensation because it stays directly warmer from the interior temperature of the building. A triple pane glass window is at least 75% more efficient against heat loss than the original single pane glass, but condensation can still result due to the physical conditions of its surroundings.

The extra measures that Comfort Windows takes to insulate our windows are unsurpassed. They are built to stop heat loss, which is a primary concern in our harsh northern climate.

September through December interior and exterior condensations become the nemeses of homeowners when they start to heat their homes. In the fall and early winter, humidity levels are still high inside the house. When outside temperatures drop drastically, they cause the exterior glass to get cold, sometimes causing condensation on the bottom of the interior glass. This usually goes away when temperatures stay low during the heart of winter.

If interior condensation continues during winter, it usually means there is a higher than acceptable level of moisture present inside the home, suggesting that ventilation and humidity levels need to be adjusted. Curtains and blinds over the window also stop the interior heat from getting to the glass, which in turn makes it colder. Condensation on the glass when blinds or curtains are first opened in the morning should be expected.

It should be noted that no Window manufacturers warrant against any type of condensation, interior or exterior, and it is specified in their written warranties.

Click on the link below to view "Your Guide To Common Household Condensation".

Condensation Guide