Discovering a non-functional or undersized exhaust system after signing a lease typically costs thousands to rectify. For food production, any process involving fumes, or any operation where ventilation is critical to compliance, the exhaust setup is one of the first things that will either enable the operation or block it entirely. This checklist is for industrial tenants assessing a unit with existing exhaust infrastructure and for those viewing units where no exhaust system exists yet but may need to be installed. What to verify when viewing a unit with existing exhaust infrastructure, and what to confirm when the unit has no exhaust system yet.
Existing Exhaust Systems
Check the hood and duct connections first. Look for corrosion, disconnected sections, and flexible ducting: flex ducting is a red flag indicating a non-compliant or poorly designed installation.
Inspect filter condition inside the hood. Clogged or missing filters mean the system has not been maintained and likely underperforms.
Turn the fan unit on and listen for abnormal noise. A grinding motor or rattling housing signals imminent failure.
Trace the duct routing path from hood to discharge point. Long routing paths with multiple bends reduce exhaust efficiency. The shorter and straighter, the better.
Confirm make-up air provision exists. Without incoming air replacing what the exhaust removes, the system will not perform as rated. If windows are sealed and no louvred supply openings are visible, make-up air is likely absent.
Check for fire dampers where ducts penetrate walls or floors. These are required by SCDF and their absence indicates either non-compliance or a modification that bypassed fire safety requirements.
Units Without Existing Exhaust
Ask building management whether a designated exhaust shaft is available. If one exists, confirm its size, routing, and whether spare capacity remains.
Check feasibility of external wall mounting. This requires building management approval and structural supports. If the building restricts external mounting and no shaft is available, routing exhaust to roof level may not be possible for that unit.
Note the number of floors between the target unit and roof. Vertical routing through occupied floors is complex and requires permission from every intervening tenant.
Enquire about the building’s approval history for exhaust installations. A building with no prior exhaust fit-outs may have unspoken restrictions or a management policy against new installations.
Confirm adequate power supply is available at the unit. Exhaust fans, especially for commercial kitchen or industrial process use, require dedicated circuits.
Building Management Questions
Ask directly about the following:
- Previous use of the unit: confirm whether it was used for food production or any process involving exhaust
- Exhaust rules and restrictions: whether the building permits new exhaust installations, and what conditions apply
- Shaft availability: whether a shared exhaust shaft exists and its current capacity
- Complaint history: whether the building has received NEA complaints related to exhaust or odour, and the outcome
- Required approvals: whether a fresh application to building management is needed before any exhaust installation
Red Flags
- No feasible routing path to roof or external discharge point
- Severely deteriorated existing ductwork
- Shared exhaust shaft at or near capacity with no available slot
- No make-up air provision and no feasible installation path for supply air
- Building complaint history involving exhaust, odour, or NEA enforcement
Summary
Exhaust system condition is one of the most overlooked items during unit viewing, and one of the costliest to fix post-lease. For units with existing systems, verify hood condition, duct integrity, fan operation, fire damper presence, and make-up air provision. For units without exhaust, confirm shaft availability or wall-mount feasibility before committing. Where the intended use involves cooking, processing, or any fume-generating activity, a failed exhaust system is not a minor inconvenience. It is an operational blocker. Confirm before you sign.
For the full exhaust and ventilation overview, see Exhaust / Ventilation / Odour Control Basics.
For make-up air requirements, see Make-Up Air Explained.
For rooftop duct routing, see Rooftop Duct Routing.
For noise control basics, see Noise Control Basics.
For grease duct maintenance, see Grease Duct Maintenance.
References
[1] NEA: Air Pollution Control — Exhaust and Emissions. https://www.nea.gov.sg/our-services/pollution-control [2] NEA: Odour Management. https://www.nea.gov.sg/our-services/pollution-control/ [3] SCDF: Acts, Codes & Regulations (Fire Safety). https://www.scdf.gov.sg/fire-safety-services-listing/downloads/acts-codes-and-regulations [4] SCDF: Fire Safety (Buildings) Regulations. https://www.scdf.gov.sg/fire-safety-services-listing/downloads/acts-codes-and-regulations [5] BCA: Building Plan Submission. https://www1.bca.gov.sg/safety-and-standards/building-control-act/ [6] MOM: Workplace Safety & Health. https://www.mom.gov.sg/workplace-safety-and-health [7] PUB: Trade Effluent Regulations. https://www.pub.gov.sg [8] JTC: Industrial Space. https://www.jtc.gov.sg/find-space/