DUCT SMOKE DETECTORS • HVAC SHUTDOWN • INSTALLATION • SERVICE • REPLACEMENT
Inline duct smoke detector installation & HVAC shutdown controls in Toronto and the GTA.
DAVESDUCTS installs, services, diagnoses and replaces applicable duct smoke detectors and integrates them with furnaces, air handlers, rooftop units and other HVAC equipment where an approved shutdown or control sequence is required. We work on residential, secondary-suite and light-commercial HVAC applications.
WHAT IT DOES
Why put a smoke detector inside an HVAC duct?
Forced-air HVAC systems can move air between areas of a building. A duct smoke detector samples air moving through the duct and can provide a control signal when smoke is detected so the HVAC system can perform the intended shutdown or other approved control function.
Smoke Sampling
A sampling arrangement directs a portion of moving duct air through the detector housing.
HVAC Shutdown
The detector can interface with compatible controls to stop a blower or equipment where that is the required control sequence.
Control Interface
Depending on the project design, the detector output may interface with HVAC controls or other approved systems.
IMPORTANT LIFE-SAFETY DISTINCTION
A duct smoke detector does not replace required smoke alarms or a fire-alarm system.
A duct detector only detects smoke that reaches its sampling point under suitable airflow conditions. It should not be treated as open-area early-warning detection for occupants. Required smoke alarms, fire-alarm devices and other life-safety systems remain separate.
SERVICE & REPLACEMENT
Already have a duct smoke detector? We can assess the HVAC side of the system.
Existing detectors and shutdown circuits can develop faults or become incompatible when HVAC equipment is replaced or controls are modified. DAVESDUCTS can diagnose applicable duct-detector/HVAC-control concerns within our mechanical scope.
Detector / Control Faults
Investigate applicable detector, sampling and HVAC-control conditions when the system is not responding as expected.
HVAC Will Not Run
Where a duct detector or shutdown circuit is involved, determine whether the HVAC interlock is contributing to the no-run condition.
HVAC Replacement
When a furnace, air handler or rooftop unit is replaced, review the existing duct-detector shutdown interface rather than assuming the old control arrangement transfers unchanged.
Detector Replacement
Replace applicable aging or failed duct detection equipment with equipment appropriate to the project requirements and control system.
Sampling Components
Review applicable sampling-tube configuration, duct location and airflow direction when performance or installation is in question.
Operational Verification
After applicable work is completed, verify the intended HVAC shutdown/control response within the project scope.
HOW IT WORKS
From duct airflow to HVAC shutdown.
01
Air Sampling
Moving duct air is directed through the detector’s sampling arrangement.
02
Detection
If smoke reaches the detector and its operating threshold is met, the detector changes state.
03
Control Signal
The detector provides its designed relay or control output to the connected system.
04
HVAC Response
The HVAC equipment performs the intended shutdown or other approved control function where designed to do so.
SECONDARY SUITES & BASEMENT APARTMENTS
Is a duct smoke detector required to legalize a basement apartment?
It can be part of the required mechanical or fire-safety design for some second-unit projects, but it is not a universal requirement for every basement apartment. The actual requirement depends on the building, HVAC arrangement, fire separation, permit/design documents and the authority having jurisdiction.
Shared Forced-Air Systems
A forced-air system serving more than one dwelling area can create specific mechanical and fire-safety considerations that should be reviewed for the project.
Permit / Design Requirements
Where drawings or permit documents specify duct detection or HVAC shutdown, the installation should follow the approved project requirements.
Confirm Before Installing
For a second-unit conversion, confirm the required scope with the municipality, designer or other responsible authority rather than installing a detector based on assumption.
COMMERCIAL HVAC
Duct detection for rooftop units and air-handling systems.
Duct smoke detectors are also used in commercial HVAC applications where the project design calls for equipment shutdown or another smoke-control function.
Rooftop Units
Applicable RTUs can be integrated with duct detection where required by the mechanical/fire-safety design.
Air Handlers
Supply or return duct detection may form part of an air-handling system’s shutdown strategy where specified.
Retrofit Projects
Existing HVAC equipment can sometimes be retrofitted with appropriate duct detection and shutdown controls when required by the project.
INSTALLATION CONSIDERATIONS
Detector location, airflow, sampling and controls all matter.
A duct smoke detector is not simply attached anywhere convenient on the duct. The installation must suit the detector, duct system, airflow and required control sequence.
Duct Location
Select an appropriate location with suitable airflow conditions and reasonable access for testing and future service.
Sampling Tube
The sampling arrangement must suit the duct dimensions and airflow direction according to the detector’s installation requirements.
Airflow
Duct detection depends on air reaching the sampling point. HVAC airflow and restrictions therefore matter to detector operation.
HVAC Interface
The shutdown/control circuit must be integrated appropriately with the furnace, air handler, RTU or other HVAC equipment.
Accessibility
The detector should remain accessible for applicable inspection, testing, reset, cleaning and replacement.
Project Documentation
Where permit, engineering, fire-alarm or mechanical documents define the sequence, equipment and installation should follow the approved design.
EQUIPMENT SELECTION
Use the detector required by the project — not simply the model that appeared on an old webpage.
The previous DAVESDUCTS page referenced the System Sensor D4120 4-wire photoelectric low-flow duct smoke detector. That remains useful for identifying existing installations, but product availability, approvals and project requirements can change.
Current equipment is confirmed for the actual installation.
DAVESDUCTS will select or confirm an applicable detector around the HVAC system, duct conditions, control requirements and project documentation rather than making every installation dependent on one historical model number.
SCOPE COORDINATION
HVAC controls and fire-alarm systems are related — but they are not the same scope.
DAVESDUCTS’ role is the applicable HVAC/mechanical installation and shutdown-control work. Projects involving a building fire-alarm system, supervised alarm circuits or other specialized life-safety work may require coordination with the appropriate designer, fire-alarm contractor, electrician or authority having jurisdiction.
DAVESDUCTS HVAC Scope
Applicable duct-detector mounting/sampling work, HVAC shutdown interface, mechanical controls and operational verification within our project scope.
Other Project Scope
Fire-alarm-system design, monitoring, annunciation, electrical or other life-safety work should be completed by the appropriately qualified party where required.
DAVESDUCTS PROCESS
From requirement to verified HVAC response.
01
Confirm
Review the requested scope and any available permit, mechanical or fire-safety documentation.
02
Assess
Review the HVAC equipment, duct location, airflow direction, controls and installation access.
03
Install
Install the applicable detector/sampling components and complete the required HVAC shutdown-control interface within scope.
04
Verify
Test the intended HVAC shutdown/control response after installation.
PUBLISHED INSTALLATION RATE
$1,175 + HST
The current DAVESDUCTS published rate for the standard duct smoke detector installation is $1,175 + HST and includes materials and labour with a one-year warranty.
Project conditions can change the required scope.
Final pricing should be confirmed before booking. Detector requirements, HVAC equipment, control wiring, access, fire-alarm integration and project documentation can vary. Work outside the standard HVAC installation scope can require additional pricing or another qualified trade.
RELATED HVAC WORK
Changing the equipment or duct system?
Duct detection should be considered as part of the HVAC system when equipment, controls or ductwork are modified.
HVAC Service & Replacement
If the furnace, air handler or other HVAC equipment is being serviced or replaced, the existing shutdown interface may need to be reviewed.
Duct Repairs & Modifications
Duct modifications can affect detector location, airflow or accessibility and should account for existing life-safety components.
HVAC Maintenance
Maintaining appropriate system airflow supports the operating conditions on which duct sampling depends.
REQUEST SERVICE
What should you send us?
- Project address / municipality
- Reason the detector is required or the problem being experienced
- Any permit, mechanical or fire-safety drawing showing the requirement
- Photos of the furnace, air handler or rooftop unit
- Equipment manufacturer and model number where available
- Photos of the proposed or existing duct-detector location
- Existing duct-detector manufacturer/model if this is a repair or replacement
- Description of the required HVAC shutdown/control sequence if documented
- Whether the project involves an existing building fire-alarm system
DUCT SMOKE DETECTOR FAQ
Installation, service and HVAC shutdown questions.
What is an inline duct smoke detector?
It is a detector designed to sample air moving through HVAC ductwork and provide a control output when smoke is detected. It is commonly used to support HVAC shutdown or another approved control function.
Does a duct smoke detector replace regular smoke alarms?
No. A duct smoke detector does not replace required smoke alarms, open-area smoke detection or a building fire-alarm system.
Does DAVESDUCTS install duct smoke detectors?
Yes. DAVESDUCTS provides applicable duct smoke detector installation and HVAC shutdown-control work for residential, secondary-suite and light-commercial HVAC applications in Toronto and the GTA.
Does DAVESDUCTS service or replace existing duct smoke detectors?
Yes, for applicable systems within our HVAC/mechanical scope. We can assess detector, sampling and HVAC shutdown-interface concerns and replace applicable equipment where required.
Does a duct smoke detector shut off the furnace or air handler?
It can when the system is designed that way. The detector’s control output can be integrated with compatible HVAC controls to initiate the required shutdown or other approved response.
Is a duct smoke detector required for every basement apartment in Ontario?
No. Requirements depend on the specific building, HVAC arrangement, fire separation, permit/design documents and authority having jurisdiction. The requirement should be confirmed for the actual project.
Where is a duct smoke detector installed?
The correct location depends on the HVAC system, detector requirements and project design. It should have appropriate airflow conditions, correct sampling configuration and access for testing and service.
Does a duct smoke detector work if the HVAC fan is off?
Duct detection relies on smoke reaching the sampling point. With little or no airflow, it should not be relied upon as early-warning detection for occupants.
Can a dirty filter or poor airflow affect duct detection?
Airflow conditions matter because the detector samples moving duct air. Significant system restrictions or inappropriate detector placement can affect sampling conditions.
Do you install System Sensor D4120 detectors?
The D4120 has been used on DAVESDUCTS projects and was the model historically featured on this page. For new work, the detector should be confirmed against current product availability, project requirements and HVAC-control compatibility.
How much does installation cost?
The current published DAVESDUCTS standard installation rate is $1,175 + HST, including materials and labour with a one-year warranty. Final scope and pricing should be confirmed because control requirements, access and project conditions can vary.
Can DAVESDUCTS connect the detector to a building fire-alarm system?
DAVESDUCTS handles applicable HVAC/mechanical detector and shutdown-control work. Fire-alarm-system wiring, supervision, monitoring or other specialized life-safety scope may require coordination with the appropriate qualified contractor or designer.
DUCT SMOKE DETECTION • HVAC SHUTDOWN • TORONTO & THE GTA
Need a duct smoke detector installed, serviced or replaced?
Send DAVESDUCTS your HVAC equipment information, project details and any permit or mechanical documentation available. We can review the applicable duct-detector and HVAC shutdown-control scope.
