The UV rays and the heat generated are both extremely damaging to the art. Alternatives include pulling drapes across windows during the day. Particulates, whether from an open fire or from a person who smokes can over time build up a damaging layer on the art. Humidity is the enemy of your art. The more moisture in the atmosphere the more danger to your art, especially paper.
Moisture causes mold to thrive.
Keeping the house at a constant temperature helps, as does not hanging art in rooms that are particularly prone to moisture, the bathroom for instance. Have your art checked regularly. We suggest that you should think about a review of your art about once every five years. This might be as simple as a visual check on each piece, or a more thorough check up if necessary. Always remember that most damage to art in the home is completely preventable and a regular check-up can help stop any damage before it starts.