There’s more than just smoke alarms to consider when installing fire protection in houses and apartments. In addition to deciding whether to use ionization or photoelectric smoke alarms, you must determine if you need to install carbon monoxide (CO) alarms or a fire sprinkler system. You also need to consider placement of any CO or smoke alarms. The rules are changing!
First of all, NFPA 72 2010 now has language in Chapter 29 that restricts you from installing a smoke alarm within 10 feet of a fixed cooking appliance. Then, between 10 and 20 feet of the appliance, you have to install either a photoelectric type or an alarm with a silence feature. An exception would apply if there is no other choice to meet code requirements. In addition, you can’t install them within 36 inches of a bathroom that contains a tub or shower. These two areas are the source of most nuisance alarms in homes and apartments (for more on these requirements, see the Fire Focus on page 66). NFPA 72 also states that, at minimum, you must have at least one smoke alarm for each 500 square feet of living space. NFPA 72 still requires smoke detectors to be installed outside each sleeping area within 21 feet of the bedroom door and in each bedroom. NFPA 101 has an exemption to eliminate the smoke alarm in bedrooms in apartments that are fully covered by quick-response sprinklers. Smoke alarms also need to be installed on each level in accordance with NFPA 72. You do not need to install smoke alarms in unfinished attics or garages.
Most homes and apartments have ionization smoke alarms installed because they are cheaper. Today, there is quite a bit of concern about nuisance alarms caused primarily by cooking fumes or steam from showers. Some jurisdictions now allow only photoelectric type smoke alarms to be installed. The problem with this requirement is it prevents any new technology detector, similar to today’s commercial multiple-criteria smoke detectors, from being installed. Proposals were submitted for the 2013 NFPA 72 that would require smoke alarms to be tested for immunity to a number of known nuisance-alarm sources. In my opinion, the greatest problem with nuisance alarms is not the type of smoke alarm installed, but the improper placement of the installed smoke alarms.
Ionization and photoelectric detectors identify different types of fire. Ionization detectors are better in detecting flaming fires, and photoelectric detectors are better for smoldering fires. Some organizations, such as the International Association of Fire Chiefs, promote using combination ion-photo detectors to respond, regardless of the type of fire.
There also are requirements for CO alarms in both the International Residential Code and the NFPA 101 Life Safety Code. Typically, they need to be installed in homes and apartments that have fossil--fuel burning equipment or attached garages. The wording may change slightly depending on the code you are using. The document used for the installation of CO alarms and detectors is NFPA 720, Standard for the Installation of Carbon Monoxide Detection and Alarms. CO alarms have a life span of approximately 5–7 years and must sound an “end of life” warning to alert the homeowner that the alarm will no longer work. CO alarms must be installed outside of each sleeping area and at least one per floor including basements. Since the location requirements are similar to smoke alarms, you could install combination CO-smoke alarms in these areas, thus saving some money and installation time.
Another recent requirement in the codes is for the installation of residential fire sprinkler systems in one- and two-family dwellings. There are a number of battles brewing around the country between the fire service and the homebuilders over residential sprinklers, and in some states, the homebuilders have been successful in eliminating the requirement. These sprinkler systems are intended to be stand-alone systems and do not have to be monitored.
The codes don’t address water flow switches yet. In my opinion, water flow switches connected to sound either a smoke alarm, a separate sounder or a fire alarm system would greatly enhance them, providing earlier warning of a fire emergency to the occupants. Having a sounder outside would also be an asset. Imagine the system activating while you are on vacation. It would be nice if it were possible for a neighbor to hear it and call the fire department to shut the water off.
There is a lot to residential fire protection today. Check your locally adopted codes or talk to your fire marshal to confirm what is required in your area.
HAMMERBERG is currently the president/executive director of the Automatic Fire Alarm Association Inc. headquartered in Jasper, Ga. He serves on a number of NFPA committees, including the NFPA 72 Technical Correlating Committee and the Protected Premises Technical Committee. He can be reached at TomHammerberg@afaa.org.