Installation Guide

w Check for exhaust backflow from CO sources. Check the draft hood on an
operating furnace for a backdraft. Look for cracks on furnace heat exchangers.
w Check the house or garage on the other side of shared wall.
w Keep windows and doors open slightly. If you suspect that CO is escaping into
your home, open a window or door. Opening windows or doors can significantly
reduce CO levels.
POTENTIAL SOURCES OF CO IN RESIDENTIAL DWELLINGS
Fuel-burning appliances like: portable heater, gas or wood burning fireplace, gas
kitchen range or cooktop, gas clothes dryer, portable generators.
Damaged or insufficient venting: corroded or disconnected water heater vent
pipe, leaking chimney pipe or flue, or cracked heat exchanger, blocked or clogged
chimney opening.
Improper use of appliance/device: operating a barbecue grill, portable generator
or vehicle in an enclosed area (like a garage or screened porch), or even your home.
550-0498
Pg. C-3
FIGURE 1: POTENTIAL SOURCES OF CO IN HOME
Transient CO Problems: transient or on-again-off-again CO problems can be caused
by outdoor conditions and other special circumstances.
The following conditions can result in transient CO situations:
1) Excessive spillage or reverse venting of fuel appliances caused by outdoor
conditions such as:
w Wind direction and/or velocity, including high, gusty winds. Heavy air in vent
pipes (cold/humid air with extended periods between cycles).
w Negative pressure differential resulting from the use of exhaust fans.
w Several appliances running at the same time competing for limited fresh air.
w Vent pipe connections vibrating loose from clothes dryers, furnaces or water
heaters.
w Obstructions in or unconventional vent pipe designs which can amplify the
above situations.
2) Extended operation of unvented fuel burning devices (range, oven, fireplace)
3) Temperature inversions, which can trap exhaust close to the ground.
4) Car idling in an open or closed garage or near a home.
5) Portable generator used in an open or closed garage or near a home.
These conditions can come and go, they are also hard to recreate during a CO
investigation.
PLACEMENT OF CO ALARMS
THIS EQUIPMENT SHOULD BE INSTALLED IN ACCORDANCE WITH THE
NATIONAL FIRE PROTECTION ASSOCIATION'S
STANDARD 720 (National Fire Protection Association, Batterymarch Park, Quincy, MA
02269).
For your information, the National Fire Protection Association's Standard 720,
reads as follows:
NFPA 720, 2015 Edition, Chapter 9, Section 9.4.1.1 Where required by applicable
laws, codes or standards for a specific type of occupancy, approved single and
multiple-station CO alarms shall be installed as follows:
1) Outside of each separate dwelling unit sleeping area in the immediate vicinity of
the bedrooms.
2) On every occupiable level of a dwelling unit, including basements, excluding
attics and crawl spaces.
3) Other locations where required by applicable laws, codes or standards.
The installation of additional CO alarms should result in a higher degree of
protection. Adding alarms to rooms that are normally closed off from the required
alarms increases the escape time because the CO levels do not need to build to the
higher level necessary to force CO out of the closed room to the required alarms. As
a consequence, it is recommended that the householder consider the installation of
additional CO protection devices. However, it should be understood that NFPA 720
does not require additional CO alarms over and above those called for in FIGURES 2,
3, 4 and 5 where required CO alarms are shown.
FIGURE 1
FIGURE 3
FIGURE 3: A CO ALARM MUST BE LOCATED BETWEEN THE SLEEPING AREA
AND THE REST OF THE DWELLING UNIT
In dwelling units with more than one bedroom area or with bedrooms on more than
one floor, more than one CO alarm is required, as shown in FIGURE 4.
FIGURE 4
FIGURE 2: A CO ALARM MUST BE LOCATED ON EVERY LEVEL OF DWELLING
UNIT, INCLUDING BASEMENT AND OUTSIDE SLEEPING AREAS
Where to Locate the Required CO Alarms. The major threat from CO in a
dwelling unit occurs at night when everyone is asleep. Persons in sleeping areas can
be threatened by CO levels in the remainder of the unit; therefore, CO alarms are best
located between the bedroom areas and the rest of the unit as shown in FIGURE 3.
FIGURE 2
FIGURE 4: IN DWELLING UNITS WITH MORE THAN ONE SLEEPING AREA, A CO
ALARM MUST BE PROVIDED TO PROTECT EACH SLEEPING AREA
In addition to CO alarms outside of the sleeping areas, NFPA 720 requires the
installation of a CO alarm on each additional level of the dwelling unit, including the
basement. These installations are shown in FIGURE 5. The living area CO alarm
should be installed in the living room or near the stairway to the upper level, or in both
locations. The basement CO alarm should be installed in close proximity to the
stairway leading to the floor above. Where installed on an open-joisted ceiling, the CO
alarm should be placed on the bottom of the joists. The CO alarm should be
positioned relative to the stairway so as to intercept CO coming from the basement
before CO enters the stairway.
FIGURE 5
FIGURE 5: A CO ALARM MUST BE LOCATED ON EACH LEVEL
Are More CO Alarms Desirable? The required number of CO alarms might not
provide reliable early warning protection for those areas separated by a door from the
areas protected by the required CO alarms. For this reason, the use of additional CO
alarms for those areas for increased protection is recommended. The additional areas
include the basement, bedrooms, dining room, furnace room, utility room, and
hallways not protected by the required CO alarms. The installation of CO alarms in
kitchens, attics (finished or unfinished), or garages is not normally recommended,
because these locations occasionally experience conditions that can result in improper
operation.