Inline duct smoke detector installation for HVAC systems.
Duct smoke detectors monitor air moving through an HVAC
duct system and can be used to initiate equipment shutdown
or related control functions when smoke is detected.
DAVESDUCTS provides applicable duct smoke detector
installation for residential and light-commercial HVAC
applications in Toronto and the Greater Toronto Area.
Samples air moving through HVAC ductwork.
Can interface with equipment controls.
Used where required by the project or authority.
Why are smoke detectors installed inside HVAC duct systems?
HVAC systems can move air between rooms and areas of a
building. If smoke enters a supply or return air system,
operating fans can potentially distribute that smoke
through the ductwork.
A duct smoke detector samples air moving through the duct
and can provide a signal to shut down HVAC equipment,
activate controls or interface with other approved systems
where required by the project design.
Its primary role is smoke-control support within the HVAC
system — not general early fire detection for occupants.
A duct smoke detector does not replace smoke alarms or a building fire alarm system.
Duct detectors only detect smoke that reaches the sampling
point while sufficient air is moving through the duct.
They are not intended to provide complete open-area
smoke detection or the earliest possible warning to occupants.
Required smoke alarms, fire-alarm devices and other
life-safety systems must remain in place independently
of the duct detector.
What happens when a duct smoke detector senses smoke?
Duct Air Passes The Detector
A sampling arrangement directs a portion of the
moving duct air through the detector housing.
Smoke Is Identified
If smoke concentration reaches the detector’s
operating threshold, the detector changes state.
Relay Or Control Output Activates
The detector can provide an output to compatible
HVAC controls, fire-alarm equipment or other
approved control circuits.
Equipment Can Be Shut Down
Where designed to do so, the control sequence can
stop the blower or perform another approved
smoke-control function.
Do you need a duct smoke detector to legalize a basement apartment?
Sometimes — but not in every home.
A duct smoke detector may form part of the required
HVAC or fire-safety design for a second dwelling unit,
particularly where a forced-air system serves more than
one dwelling area or where specific shutdown controls
are required.
The actual requirement depends on the building,
mechanical system, fire separation, permit documents
and the requirements of the municipality or authority
having jurisdiction.
If you are legalizing a basement apartment, DAVESDUCTS
recommends confirming the required mechanical and
fire-safety scope with the building department,
designer or other responsible authority before
installation.
Where might a duct smoke detector be used?
Secondary-Suite HVAC Systems
Some second-unit projects may require duct smoke
detection or HVAC shutdown controls depending on
the mechanical and fire-safety design.
Rooftop & Air-Handling Equipment
Duct smoke detectors are commonly associated with
larger air-handling and rooftop systems where smoke
control or equipment shutdown is required.
Existing HVAC Systems
Existing equipment can sometimes be retrofitted
with duct detection and shutdown controls when
the project design requires it.
Mechanical-System Shutdown
The detector may be used to stop HVAC operation
when smoke is detected so the air system does not
continue recirculating smoke.
Proper placement and wiring matter.
Correct Duct Position
The detector should be installed in an appropriate
duct location with the necessary airflow conditions
and service access.
Proper Sampling Tube Setup
Sampling tubes and detector configuration must suit
the duct size and airflow direction so air is
properly drawn through the detector.
HVAC Shutdown Interface
The detector must be correctly integrated with the
furnace, air handler, rooftop unit or other control
system where shutdown is required.
Testing & Service
The installed detector should remain accessible
for inspection, testing, reset and future service.
Can dirty filters or low airflow affect duct smoke detection?
Yes. Duct smoke detection depends on air moving through
the duct and through the detector’s sampling arrangement.
Excessive airflow restriction can reduce the amount of
air available for proper sampling.
HVAC maintenance and proper airflow therefore remain
important even after a detector is installed.
Detector make and model should match the project requirements.
DAVESDUCTS’ previous page referenced the System Sensor
D4120 4-wire photoelectric low-flow duct smoke detector.
That is useful historical product information, but we
would not make the page dependent on one model.
Product lines and approvals can change, so the detector
supplied should be selected based on the current project
requirements, HVAC controls and applicable documentation.
How we approach a duct smoke detector installation.
Confirm The Requirement
We review the requested scope, mechanical system
and any applicable permit or design requirements
provided for the project.
Review The HVAC System
Duct location, airflow direction, equipment controls
and available installation access are evaluated.
Install & Wire
The detector and sampling components are installed
and connected to the required HVAC shutdown or
control circuit.
Test The Response
Operation and the intended HVAC shutdown/control
response are verified after installation.
$1,175 + HST
The current DAVESDUCTS page lists this rate as including
materials and labour with a one-year warranty.
Final pricing should be confirmed before booking because
detector requirements, wiring, HVAC controls and project
conditions can vary.
Common duct smoke detector questions
What is a duct smoke detector?
designed to sample air moving through an HVAC duct.
It can be used to initiate HVAC shutdown or other
approved control functions when smoke is detected.
Does a duct smoke detector replace regular smoke alarms?
open-area smoke detectors or a building fire-alarm
system. Its purpose is primarily related to smoke
movement through the HVAC system.
Does a duct smoke detector shut off the furnace or air handler?
are designed that way. The detector’s relay or
control output can be used to interrupt blower
operation or provide another required control signal.
Is a duct smoke detector required for a basement apartment in Ontario?
depend on the building, HVAC layout, fire separation,
permit design and the authority having jurisdiction.
The applicable municipality or project designer should
confirm the requirement for the specific second-unit
conversion.
Where is a duct smoke detector installed?
requirements. It may be installed in supply or return
ductwork where sufficient airflow is available and
the detector remains accessible for testing and service.
Does a duct smoke detector work when the HVAC fan is off?
its sampling point. If little or no air is moving
through the duct, it should not be relied upon as
an early-warning detector for the occupied space.
Does DAVESDUCTS install duct smoke detectors in Toronto and the GTA?
detector installation and HVAC shutdown-control work
for residential and light-commercial projects in
Toronto and the Greater Toronto Area. Contact us
with the project details and any permit or mechanical
documentation available.
Need a duct smoke detector installed?
Send DAVESDUCTS the project details, HVAC equipment
information and any permit or mechanical-design
requirements you have. We can review the installation
and determine the appropriate HVAC detector and
shutdown-control scope.
