A: Remember: Windows do not cause condensation, therefore windows cannot cure condensation!

Condensation and ice form on windows because the temperature of the window surface is below the dew point for the air near the window. The colder temperature of the glass causes the moisture in the air to "condense out" onto the glass. To eliminate condensation you either need to raise the temperature of the window surface or reduce the relative humidity in the room. If the condensation is on a double glazed window and the temperature outside is above zero the problem is probably high indoor relative humidity. The best way to deal with condensation on high quality, double glazed windows is to reduce indoor relative humidity to no more the 40 percent.

Several conditions can increase condensation problems. Closing drapes causes the glass temperature and the temperature of the air between the drape and the glass to become cooler, making condensation more likely. If the thermostat setting is dropped substantially at night, this will cause an increase in relative humidity and may increase condensation. This condensation should vanish once the temperature rises in the morning.

Q: I hope you can help me. Our windows are twin-pane and they have condensation in the middle. This does not look very nice and we were told that we could drill a small hole and the condensation would go away. Is this true? And if so, do we drill on the inside window or the outside window and just one hole? Thank you.  

A: The reason you have moisture between your panes of glass is that the seal has  failed allowing water or moisture to enter. Drilling a hole will not alleviate your problem and can potentially make it worse. The only way to rectify this is to replace the insulating glass (IG) unit. Check your warranty to see if the manufacturer has a full or pro-rated warranty on the sealed-glass unit. You may be able to have the unit replaced for little or no cost if it isn't that old. If you do not have a warranty or cannot find the manufacturer, a local glass house can probably replace the IG unit for you. This is mostly likely what you didn't want to hear, but it's the best solution for correcting the situation.