NFPA 90A requires duct detectors to be installed on the supply side of air handler units with airflows of more than 2,000 cubic feet per minute (cfm). The standard also requires a duct detector on the return side of any unit with air flows exceeding 15,000 cfm and which serve more than one floor of a building.
Simply so, can duct detectors be mounted vertically?
Mounting the detector housing in a vertical orientation is acceptable provided that the air flows directly into the sampling tube holes as indicated in Figure 3. … The end cap is needed to create the proper air flow to the sensor of the duct smoke detector.
Just so, does a make up air unit require a duct smoke detector?
It is true that with most traditional recirculating air distribution systems, installation of an HVAC smoke detector is required. … Cambridge Air Solutions systems, including make-up air units, ventilation systems and industrial heaters use only 100-percent outdoor air to heat and ventilate.
How are duct detectors installed?
To ensure correct operation, install the duct detector using the following guidelines: Install the duct smoke detector on a flat section of HVAC duct between six and ten duct widths from any bends or obstructions. Install supply-side detectors at a point downstream from the supply fan and after the air filter.
How do you test a duct detector?
Spray aerosol smoke* into the duct through the ΒΌ inch hole for five seconds. Wait two minutes for the duct smoke detector to alarm. If the duct smoke detector alarms, air is flowing through the detector.
How do you wire a duct detector?
How does a duct smoke detector work?
How Do They Work? Duct detectors sample currents in the air handling equipment to determine if smoke or fumes are present. If smoke is detected, the device will close dampers, stop fans and blowers, and trigger an audible and visible signal at the fire control panel, Kapparos explains.
How many type of duct detectors are there?
Make sure to connect the duct smoke detector correctly
In general terms, there are basically two types of smoke detector: those with an external control unit and those with a built-in control unit.
What is the largest return air opening that can be protected with a single smoke detector?
Where do you put a duct smoke detector?
NFPA 90A requires duct smoke detectors to be located in the supply duct downstream of air filters and ahead of any branch connections.