What is a make-up air unit?

A make-up air unit (MAU) brings fresh outdoor air into a building, conditions it (heating in winter, sometimes cooling in summer), and distributes it through ductwork. In condos, MAUs typically provide fresh air to corridors and common areas while maintaining positive pressure for fire safety and odor control.

How long does MAU replacement take?

Timeline depends on unit size, location, and whether ductwork modifications are needed. Typical rooftop MAU replacements take 1-3 weeks from removal to commissioning. Projects requiring significant ductwork or structural modifications may take longer.

Will the building be without ventilation during replacement?

We minimize ventilation downtime by pre-staging equipment and materials. For single-MAU buildings, downtime is typically 2-5 days. Buildings with multiple units can be staged to maintain partial ventilation throughout the project.

What are the benefits of a new MAU?

Modern MAUs offer significantly better energy efficiency through heat recovery, variable speed fans, and improved controls. They also provide better filtration, quieter operation, and integration with building automation for optimal performance.

MAU Replacement: Breathe Fresh Air Into Your Building

Make-up air units are the lungs of your building—bringing in fresh outdoor air, conditioning it, and distributing it throughout corridors and common areas. When they fail, indoor air quality suffers and corridor pressurization is compromised.

We manage complete MAU replacement projects from equipment selection through commissioning. Whether you need a simple like-for-like replacement or a full system upgrade with energy recovery, our team ensures minimal downtime and optimal performance.

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Make-up air unit replacement project Toronto

Improved air quality

Modern MAUs with high-efficiency filtration remove more particulates, allergens, and contaminants. Better fresh air delivery means healthier corridors and common areas.

Energy savings

New units with energy recovery wheels or plates capture 60-80% of heat from exhaust air. Variable speed fans match airflow to actual demand, slashing energy costs.

Proper pressurization

Correctly sized and balanced MAUs maintain positive corridor pressure—essential for fire safety, odor control, and preventing suite-to-suite air transfer.

Types of make-up air systems

Different buildings have different ventilation requirements. We work with all common MAU configurations and can recommend the best approach for your building's needs.

Rooftop MAU

Self-contained units on the roof with ductwork down through the building. Most common in Toronto high-rises.

Penthouse AHU

Larger air handling units in mechanical penthouses, often serving multiple zones or functions.

Energy Recovery

Units with heat wheels or plates that recover energy from exhaust air to pre-condition incoming fresh air.

Gas-Fired

Direct-fired or indirect-fired gas heating for efficient winter operation. Common in older Toronto buildings.

Hydronic Heating

Hot water coils connected to building boiler system. Integrates with existing heating infrastructure.

Electric Heat

Electric heating coils for buildings without gas or where electric is preferred. Simple but higher operating cost.

Old make-up air unit requiring replacement

Why proactive MAU replacement?

Aging make-up air units don't just lose efficiency—they compromise the entire building's air quality and fire safety systems. Proactive replacement ensures continuous, reliable ventilation.

Fire safety: MAUs maintain positive corridor pressure that prevents smoke spread between floors. A failed unit compromises this critical safety system.
Odor control: Proper pressurization prevents cooking odors, smoke, and other contaminants from transferring between suites and into corridors.
Energy costs: Old units with constant-speed fans and no heat recovery waste enormous amounts of energy. Modern units can cut ventilation energy costs by 40-60%.
Resident comfort: Properly functioning MAUs maintain comfortable corridor temperatures year-round and ensure adequate fresh air throughout the building.

Our replacement process

MAU replacement requires careful planning to minimize ventilation downtime while ensuring proper installation and commissioning.

Assessment

Existing equipment evaluation
Airflow measurements
Ductwork inspection
Rigging path evaluation
Load calculations

Engineering

Equipment selection
Energy recovery options
Controls integration plan
Structural review (if needed)
Permit applications

Procurement

Equipment ordering
Lead time management
Crane/rigging booking
Utility rebate applications
Material staging

Removal

Gas/electrical disconnection
Ductwork separation
Old unit rigging
Curb preparation
Disposal

Installation

Unit placement
Ductwork connections
Gas piping (if applicable)
Electrical hookup
Controls wiring

Commissioning

System startup
Airflow balancing
Pressurization testing
BAS integration
Documentation

MAU manufacturers we install

We work with leading air handling equipment manufacturers and can recommend the best fit for your building's requirements and budget.

Engineered Air

Custom air handling

Trane

Commercial AHUs

Carrier

Rooftop & AHU

Renewaire

Energy recovery

Ventrol

Custom ventilation

York

Air handlers

Daikin

Rooftop units

Greenheck

Ventilation systems

Also installing: Reznor, Lennox, McQuay, Aaon, and other commercial air handling manufacturers. We help select equipment based on your building's specific requirements including capacity, efficiency targets, space constraints, and total cost of ownership.

Compliance & safety

MAU replacement involves gas, electrical, and rooftop work—all with significant safety and code requirements. We handle all compliance aspects.

TSSA & Gas Code

Gas-fired units installed and certified by licensed gas technicians. All required permits and inspections coordinated and documented.

Electrical Permits

Electrical work by licensed electricians with proper permits and ESA inspection. Panel upgrades coordinated if needed for new equipment.

Rooftop Safety

Full fall protection compliance for rooftop work. Crane operations coordinated with proper permits and traffic control where required.

For property managers & boards

MAU replacement is a significant capital project that directly impacts resident comfort and building safety. We understand the importance of proper planning and communication.

Board presentations: We present options clearly, explaining trade-offs between equipment types, efficiency levels, and costs.
Reserve fund alignment: Projects can be timed to match funding availability, with documentation supporting reserve fund study updates.
Utility rebates: Energy recovery units often qualify for significant utility incentives. We identify and apply for applicable programs.
Minimal disruption: We schedule work to minimize ventilation downtime and coordinate with building operations to avoid conflicts with other activities.

MAU Projects Across Toronto

We've completed make-up air unit replacements in buildings across the GTA—from single-unit mid-rises to multi-MAU high-rise complexes. See our project portfolio for examples.

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FAQs

A make-up air unit (MAU) brings fresh outdoor air into a building, conditions it (heating in winter, sometimes cooling in summer), and distributes it through ductwork. In condos, MAUs provide fresh air to corridors and common areas while maintaining positive pressure. This pressurization is critical for fire safety (preventing smoke spread) and odor control (preventing suite-to-suite transfer of cooking smells and smoke).

Equipment lead times currently range from 8-16 weeks depending on manufacturer and specifications. Once equipment arrives, on-site work typically takes 1-3 weeks from old unit removal to commissioning. Ventilation downtime is minimized—usually 2-5 days for a single-unit building. We coordinate crane access, weather windows, and building activities to ensure efficient execution.

Energy recovery systems (heat wheels or plates) capture 60-80% of heat from exhaust air to pre-condition incoming fresh air. In Toronto's climate, this dramatically reduces heating costs in winter. Units with energy recovery typically pay back the additional cost within 3-5 years through energy savings, and often qualify for utility rebates that further improve the economics.

Yes, this is a common upgrade. However, energy recovery units are typically larger and may require ductwork modifications. We assess feasibility during the proposal phase including structural capacity, available space, and ductwork routing. The additional first cost is often justified by energy savings and utility rebates.

We minimize ventilation downtime through careful planning and pre-staging of materials. For buildings with multiple MAUs, we can stage replacement to maintain partial ventilation. For single-MAU buildings, downtime is typically 2-5 days. We coordinate timing with building management and provide advance notice to residents. Temporary ventilation measures can be arranged if extended downtime is unavoidable.

Costs depend on unit capacity, type (gas vs. hydronic vs. electric), energy recovery inclusion, and rigging requirements. Typical rooftop MAU replacements range from $50,000 to $200,000+. Energy recovery adds $15,000-40,000 but often qualifies for utility rebates and pays back through energy savings. We provide detailed proposals after site assessment.

Ready to upgrade your building's ventilation?

Request a site assessment and detailed proposal. We'll help you understand your options, timeline, and budget requirements for a successful MAU replacement.

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