Don't install alarms where air movement can delay the alarm. This means they should be away from windows and at least 3 feet from warm or cold air ducts or return ducts. Also, don't install them between an air return and a bedroom door.
- Within 3 feet of an air supply vent (supply or air flow) - Within 1 foot of a light fixture. - Within the “dead air space” where the wall meets the ceiling (ceiling smoke alarms must be at least 4” from the wall, wall mounted smoke alarms must be at least 4” and no more than 12” from the ceiling.
Guideline. The guideline in this case is that you shouldn't put alarms within 400mm of air conditioning vents or the blades of a ceiling fan, however we recommend 1m if possible.
Do not site detectors less than 1m from air supply points or air circulating units. A device should not be mounted within 500mm of any obstruction.
Annex A, A. 17.7. 4, recommends that detectors not be located in the direct airflow or closer than 36 inches from air supply diffuser or return air opening. This recommendation is intended to prevent airflow from diluting smoke or delaying smoke reaching the detector, both of which can significantly delay detection.
Many building owners working through retrofit or new construction projects are familiar with International Mechanical Code (IMC) standards, which state that an HVAC smoke detector be installed on any air handling system with a capacity greater than 2,000 cubic feet per minute (CFM).
The most common application of the Point 7 Rule is smoke detectors in corridor applications. Applying the Point 7 Rule allows spacing between smoke detectors to be extended beyond 30 feet in corridors that are less than 30 feet wide.
On every occupiable level of a dwelling unit, including basements. 3. Where a fuel-burning appliance is located within a bedroom or its attached bathroom, a carbon monoxide alarm shall be installed within the bedroom. Alarms shall be installed at a minimum distance of 3 feet from fans and vents.
Install smoke alarms inside and outside every bedroom and sleeping area (like a hallway). Install on every level of the home, including the basement. A smoke alarm should be on the ceiling or high on a wall. Keep smoke alarms away from the kitchen to reduce nuisance, or false, alarms.
For many years NFPA 72, National Fire Alarm and Signaling Code, has required as a minimum that smoke alarms be installed inside every sleep room (even for existing homes) in addition to requiring them outside each sleeping area and on every level of the home. (Additional smoke alarms are required for larger homes.)
You may have noticed while looking through these explanations that problems associated with air conditioners are not listed. This is due to the fact that air conditioners do not, in fact, play a direct part in triggering your smoke alarms.
Install smoke alarms in all circulation areas/ escape routes and high risk areas. Have at least one smoke alarm in every circulation space on each storey (such as hallways and landings) Position at least one smoke alarm in the principal habitable room (generally the living room)
Smoke alarms and smoke detectors shall not be installed within a 36 in. (910 mm) horizontal path from the supply registers of a forced air heating or cooling system and shall be installed outside of the direct airflow from those registers.
An enclosed, individually exhausted, negative-pressure room won't prevent smoke from traveling into adjacent spaces. Standard HVAC systems by themselves don't control secondhand smoke exposure and may help distribute smoke particles and gases.
NFPA 90A and International Mechanical Code
The International Mechanical Code requires a duct smoke detector in the return for units over 2000 cfm and requires a detector in the supply duct for systems over 15,000 cfm.
Carbon monoxide is lighter than air. It also rises with warm air, so the United States Environmental Protection Agency (EPA) recommends placing a carbon monoxide detector on a wall about five feet above the floor or about eye level. You can put them on the ceiling, too.
According to the United States Department of Homeland Security, and the California Building Code, at least one smoke detector needs to be placed in each of the following areas of your home: On Every Floor Level. In Every Bedroom. In Every Hallway Outside of a Bedroom.
Causes of Carbon Monoxide Poisoning
Ways carbon monoxide can enter your home include: Blocked vents: During the winter months especially, it's important to keep your furnace vents, intake valves, and chimneys free of snow.
“(2)* All points on the ceiling shall have a detector within a distance equal to or less than 0.7 times the nominal 30 ft. (9.1 m) spacing (0.7S).
Install a least one on every level of the home, including the basement. Place a smoke detector in every sleeping area. Ensure a smoke alarm is outside of every room, like in a hallway.
Have smoke alarms on every level of your home and in each bedroom and hallway. If you mount alarms on the ceiling, place them 4 inches from the wall. If your alarms are on the wall, they should be 4 to 12 inches from the ceiling. Don't install alarms near windows, vents, or drafty areas.
The NFPA requires AC-powered, interconnected smoke alarms to be installed inside each bedroom, outside each bedroom area, and on every level of the home. They also require a minimum of two AC-powered, interconnected smoke alarms in any new construction home.
If you are installing only one carbon monoxide detector, the Consumer Product Safety Commission (CPSC) recommends it be located near the sleeping area, where it can wake you if you are asleep. Additional detectors on every level and in every bedroom of a home provide extra protection against carbon monoxide poisoning.
5.6. 5.1 of NFPA 72-2010 says you need to have smoke detection within 5 feet of the door. If the wall section above the door (sometimes called a 'transom') is greater than 24 inches, then you need a smoke detector on both sides of the door.