Make-Up Air System Design in Ontario
NFPA 96 compliant make-up air system designs for Ontario restaurants and commercial kitchens — exhaust hood pressure balancing, direct-fired MUA units, heat recovery options, stamped by a PEO-licensed engineer.
Get a Free QuoteWhat's Included
- Commercial kitchen exhaust airflow calculation per NFPA 96 requirements
- Make-up air unit sizing to balance exhaust hood airflow and building pressure
- Direct-fired, indirect-fired, or heat recovery MUA unit selection
- HRV/ERV integration options for energy recovery on high-exhaust systems
- Ductwork layout for MUA supply and distribution within the kitchen
- Building pressure analysis — negative pressure issues diagnosed and resolved
- Control sequence design — fan interlock with exhaust hood activation
- Electrical coordination summary for MUA unit power requirements
- Stamped drawings for building permit and health department submission
Turnaround
3–5 business days from receipt of architectural drawings. Rush service is available for urgent projects.
Deliverables
- Stamped MUA system drawings (PDF) — unit location, ductwork, and controls
- Exhaust airflow and MUA sizing calculation sheet
- Equipment schedule with MUA unit specifications
- Control sequence of operations
- NFPA 96 compliance notes
Codes & Standards
- NFPA 96 — Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations
- OBC 2024 Part 6 — Ventilation
- ASHRAE 62.1 — Ventilation for Acceptable Indoor Air Quality
- UL 710 — Exhaust Hoods for Commercial Cooking Equipment (equipment reference)
- Local fire marshal requirements (municipality-specific)
Who This Is For
Restaurant owners, food service operators, commercial kitchen designers, and architects fitting out Ontario food service spaces. Required any time a commercial cooking exhaust hood is installed — the OBC and NFPA 96 require the exhaust to be balanced with a corresponding make-up air system.
Frequently Asked Questions
Why is a make-up air system required for commercial kitchens?
Commercial kitchen exhaust hoods remove large volumes of air from the building — often 2,000 to 10,000 CFM or more. Without a dedicated make-up air system replacing that exhaust air, the building goes strongly negative, causing doors to be hard to open, combustion appliances to back-draft, and the exhaust hood to underperform. NFPA 96 and OBC Part 6 both require make-up air to balance the exhaust.
What type of make-up air unit is right for my kitchen?
The most common choice for Ontario restaurants is a direct-fired gas MUA unit, which heats supply air efficiently across the full range of Ontario outdoor temperatures. Indirect-fired units are used where direct flame contact with supply air is not permitted. Heat recovery units are increasingly used in high-volume operations to reduce energy costs.
How close to 100% does the MUA need to balance the exhaust?
Best practice is 80–90% MUA to exhaust, with the remaining 10–20% made up through transfer air from adjacent spaces. A perfectly balanced or slightly negative kitchen is the target — slight negative pressure keeps cooking odours from migrating to the dining area.
Do you coordinate with the exhaust hood supplier?
Yes. We work from the hood manufacturer's exhaust airflow specifications and design the MUA system to balance those specific flow rates. If the hood is not yet selected, we can specify the exhaust airflow requirements and work backwards from target CFM values.