Residential home fire alarm protection methods can be broken down into two distinct applications: stand-alone detection devices, known as smoke alarms or carbon monoxide (CO) alarms, and combination fire alarm and detection systems that employ smoke detectors and CO detectors connected to a residential fire alarm system control unit.


Most spec home builders will only want the minimal code-required smoke and CO alarms. These individual devices are not systems and simply exist as an interconnection of devices powered by alternating current (AC) with an integrated detection component and an alarm component; they provide minimum life safety protection for the occupants with only a local alarm within the home. They do not possess the ability to send a signal to a remote supervising station, nor are they monitored for integrity. If the owner chooses to remove them or disconnect the power sources, no one outside the home will know.


As a contractor providing these devices, you need to have a copy of NFPA 72 2013, National Fire Alarm and Signaling Code, and NFPA 720 2012, Standard for the Installation of Carbon Monoxide (CO) Detection and Warning Equipment, to ensure that you correctly install a sufficient number of these devices to comply with the code requirements.


Typically, the code requires you to install smoke alarms and CO alarms outside of each separate dwelling-unit sleeping area in the immediate vicinity of the bedrooms and on every occupiable level of a dwelling unit, including basements but excluding attics and crawl spaces.


Some of these devices are combination units, making compliance with the code requirements relatively easy. The location of the combination devices does not generally depend on mounting height for effective performance. CO and air at room temperature have similar densities that generally mix readily. However, ceiling mounting is the preferable location.


The code requires installers to interconnect these devices, especially where a dwelling has separated sleeping areas. To ensure the occupants can hear the alarm from one device, all of the alarm appliances within the other devices must actuate.


Sophisticated builders and homeowners who build the larger, more expensive homes will want more than the minimum code requirements. They will usually choose to install combination smoke and CO system detectors connected to a listed residential fire alarm system control unit. In fact, they will generally want a monitored security system as well as a more sophisticated fire alarm and CO system. 


This presents an opportunity to design and install these systems, upsell the type and amount of security and fire protection, and integrate other systems that will meet the homeowner’s safety and comfort goals. In developing your proposal, you should understand that, if the only CO-generating appliance in their home consists of a vehicle in a garage, you still should include CO detection in the overall system design. Recent research reports show that CO generated by a vehicle in an attached garage will penetrate gypsum walls, and the occupants will feel the effects.


To design and install security and fire alarm systems, you still need to completely understand the customer’s protection goals. The customer will know generally what features he or she wants, but you will need to present them with all of their protection options.


For example, they may desire the life safety protection afforded by the fire alarm system, and they may want to ensure the system design provides more complete protection to minimize their property losses. Adding detection will often help you achieve this goal—don’t forget the attic and garage—but detection by itself may not limit the losses enough to satisfy the owner’s property-protection goals. In order to judge whether or not you can meet these goals, you will need to understand the water availability and fire departments’ capabilities and their response time. This information—which you need to know prior to sitting down to discuss options with the owner—will help you to better judge if more early detection will compensate for any negative fire department- or water-related aspects..


Early in the selling process, you want to establish yourself as the go-to person for all protection, so now may be a good time to recommend the owner purchase a residential sprinkler system. I am not advocating that you become a sprinkler system designer and installer, rather I’m suggesting you team up with a company that matches your good reputation. Then, when you are in front of the customer, you will have the necessary answers. One of the answers you can give when the customer expresses concern over water damage from a sprinkler system is that your fire alarm system will monitor the sprinkler system, so any inadvertent water discharge will report through your system to the supervisory monitoring company.


The owner may have other low-voltage systems that he or she would like to have installed such as temperature monitoring and control, or at least low-temperature monitoring, to avoid frozen pipes during a winter cold snap with concurrent power loss. You also can add devices to the security/fire alarm system to monitor water leakage.


To comply with the code, you need to understand the requirements for combination systems as defined in NFPA 72. Typically, a combination system includes “a fire alarm system in which components are used, in whole or in part, in common with a non-fire signaling system.” As mentioned previously, you may combine a fire alarm system with nonfire systems that include a security, access control, background music, paging and building automation to name a few. In many cases, the nonfire systems connect to the fire alarm system, and the nonfire system reacts to signals from the fire alarm system.


In many cases, with systems such as CO detection, fire extinguisher electronic monitoring devices, emergency communication (mass notification), or intrusion, one benefit of combining systems comes from using common wiring.


The code states in the annex that, “If the equipment in the combination system is of equivalent quality to fire alarm equipment, and the system monitors the wiring and equipment in the same way as fire alarm equipment, then sharing of wiring is permitted. If the equipment is not of equivalent quality, isolation between the systems would be required.”


Therefore, ensure that the equipment you include in the combination system within the residence meets both the owner’s protection goals and the code requirements. This way, you provide economic benefits to the owner as well.


Another design issue you need to consider when planning combination systems stems from the requirement that fire alarm signals must be distinctive, clearly recognizable and be indicated in descending order of priority, except where otherwise required by other governing laws, codes or standards, or by other parts of the code as follows: “(1) Signals associated with life safety, (2) Signals associated with property protection, (3) Trouble signals associated with life and/or property protection, [and] (4) All other signals.”


As with any sophisticated system, avoid providing confusing information to the first responders. The code allows the authority having jurisdiction to permit only the display of required fire alarm system information as a priority at the remote annunciators and fire alarm control units.


However, the code does require that signals from CO detectors and CO detection systems transmitted to a fire alarm system shall indicate as “Carbon Monoxide Alarm” on the fire alarm system control unit or annunciator.


So, depending on the customer’s sophistication, you have the opportunity to increase your overall sales package by specifying a code-complying combination system whenever such a system will best meet the customer’s wishes and protection goals. As a top-rated contractor, it becomes a part of your job to know the code requirements and to fully understand the systems technology available to do the job.