When considering installation, be aware that Carbon Monoxide has the same density as air and, therefore, distributes equally around a room. However, as CO is formed by a combustion process, the gas is likely to be hotter than the surrounding air and will be forced towards the ceiling. Detailed recommendations can be found in EN50292, a guide on selection, installation, use and maintenance for residential CO alarms. Ideally, an alarm should be fitted in every room that contains a fuel burning appliance and for additional safety, fit one in each bedroom.
For premises such as bedsits, caravans or boats where the accomodation is a single living space incorporating the sleeping area, the alarm should be positioned as far from the cooking appliances as possible, but near to where the person sleeps.
The alarm should be fitted on the ceiling, as close to the centre of the room as possible but at least 50 cm (20 inches) from any wall or light fitting. This is to avoid dead air in the corners of the room where smoke might not reach, or possible obstruction by light fittings.
It is the responsibility of the installer to ensure the product is installed in line with current regulations. If in doubt please consult a competent professional installer.