Because carbon monoxide is slightly lighter than air and also because
it may be found with warm, rising air, detectors should be placed on a
wall about 5 feet above the floor. The detector may be placed on the
ceiling. Do not place the detector right next to or over a fireplace or
flame-producing appliance. Keep the detector out of the way of pets and
children. Each floor needs a separate detector. If you getting a single
carbon monoxide detector, place it near the sleeping area and make
certain the alarm is loud enough to wake you up.