Dry conditions can lead to guitar damage. A guitar humidifier will protect your acoustic guitar and keep it playing and sounding its best.
Most acoustic guitars are built in a relative humidity (RH) range of 45%-50%. This range is right in the middle of the average yearly climate swing in countries where guitar is most popular. The danger to your guitar occurs during the fall, winter, and early spring heating seasons. The colder it is outside, and the more you need to heat your home, the drier the air becomes in your home. It can often drop to less than half of the RH of the factory. When the RH in your home drops to 35% or lower, look out! The guitars top will start to sink in, the neck angle can change, cracks often occur in the top, the bridge can lift from the top, and action will drop, causing fret buzz. Most guitar manufacturers will not honor warranties if you allow your guitar to dry out like this, and the resulting repairs can be very expensive.