Make-Up Air Units · Greater Toronto Area

Commercial Make-Up Air Unit Service in the GTA

Ventilation equipment service focused on airflow, heating, pressure balance and dependable outdoor-air delivery.

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Commercial & industrial HVAC support across the Greater Toronto Area.

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Equipment overview

Replacement air that works with the building

Make-up air units introduce conditioned outdoor air to replace air removed by exhaust systems and other building processes. When airflow, heating or controls drift, the result may be pressure imbalance, comfort complaints or ventilation problems. Sensible reviews the unit together with its operating schedule and connected building conditions.

Where this equipment is used

Commercial kitchens and restaurants
Warehouses and distribution facilities
Manufacturing and industrial spaces
Fitness, retail and high-exhaust buildings

Commercial make-up air unit installed on a flat roof

Signs you need make-up air unit repair

Airflow falling off, or the building going negative when exhaust runs
Burner or heating-stage faults on cold mornings
Belt, bearing or motor noise at the unit
Outdoor-air dampers not opening or closing as commanded
Cabinet, panel or weather-seal damage after a hard season
Sensors and schedules calling the unit at times the building does not need it

Signs you need make-up air unit replacement

Outdoor-air capacity that no longer balances the exhaust it serves
Heating capacity that cannot temper design outdoor air
Cabinet or casing condition that repair no longer holds
Curb, duct or utility interfaces that limit what repair can achieve
Repairs recurring on the same components across heating seasons
A kitchen or process change that alters the airflow the unit was sized for

Signs you need make-up air unit preventative maintenance

Filters, belts, drives and bearings with no scheduled inspection
Dampers, heating stages and operating controls never reviewed
Cabinet, panels, weather seals and drainage left unchecked
Airflow concerns not documented alongside the exhaust they relate to
No pre-season check before the heating load arrives
Coordinated exhaust issues raised as separate calls rather than one problem

Schedule Service

Why does the building feel draughty when the kitchen exhaust runs?

That is usually a make-up air balance problem rather than a door or window one. If the unit is not delivering the outdoor air the exhaust is removing, the building goes negative and pulls air through every other opening it can find. The two systems have to be looked at together.

How often should a make-up air unit be serviced?

ANSI/ASHRAE/ACCA Standard 180 sets inspection and maintenance tasks at defined frequencies for commercial HVAC equipment. Make-up air units earn a pre-season check before heating, since a burner or damper fault that goes unnoticed in summer shows up on the first cold morning.

Why will the unit not heat properly in cold weather?

Tempering design outdoor air is demanding, so the usual causes are heating stages not all firing, a damper letting in more outdoor air than the burner can temper, or a control sequence that is not staging correctly for the conditions.

Should the make-up air unit and the exhaust be serviced together?

Where they serve the same space, yes. Airflow concerns on one side are frequently caused by the other, and treating them as separate service calls tends to mean the same problem gets diagnosed twice.

What is involved in replacing a make-up air unit?

The work turns on the outdoor-air and exhaust relationship, on heating, cooling and airflow requirements, and on the existing curb, duct, utility and controls connections. Start-up and functional operating checks are part of the job, not a follow-up visit.