Ahhh winter, the season that my wife hates. Along with the higher heating bills comes along dry skin, chapped lips and cracks in walls and ceilings. The colder air of winter is not able to hold as much moisture as warmer air has the potential to do. As the dryer winter air normally infiltrates the home the home itself can become dryer. This drying of the home air and the materials used to build the home results in the materials shrinking a bit and the small cracks will form. Usually the cracks will form where sections of drywall meet. This is common and not a structural concern. It is common for Ohio home inspectors to find cracks in the ceiling and walls. The image above is where the ceiling and wall meet in a home where the humidity level was a dry 28%.
The commonly recommended humidity range for a home is 35-50%. If over 60% the chance of mold increases. If the humidity levels are low then the chances of dry skin, chapped lips, dry throats, wall cracks and static (you do get to zap your friends and family with this) rise.
To increase moisture in the air use a humidifier. These are not expensive and will help out. You can also get a humidifier to attach to the furnace duct work. These things will work very well. However if they develop a leak you will not see the leak immediately. Another great way to add moisture to the air is to cook pasta and leave the lid off the boiling water. Not only will you add moisture, you will also feed yourself.
The keep humidity levels low in the more humid months you will need to use an air conditioner and or a dehumidifier (usually placed in the basement)