Make-Up Air Units (MAU)
Refresh the Air
Make Up Air Units (MAU) are specifically designed to bring in fresh air to replace the air that is being exhausted. Commercial buildings can have a variety of tenants that occupy the space at the same time. For this reason, it’s especially important to cycle the air. There are often food courts and office kitchens that need to be ventilated so the smell of cooking does not sit stagnant in the building. For buildings that have commercial cooking appliances and hood fans, make up air units also prevent dangerous backdrafts which keep cooking staff and their surroundings safe.
Indoor air quality is another concern that make up air units help to maintain. A system with great ventilation will ensure that the health and comfort of the building occupants is also addressed, including proactively preventing mold build up in moist areas. Additionally, MUA contributes to the equalization of pressure in your building. This helps keep doors from being too difficult to open or slamming shut behind you due to negative air pressure.
MAU Installations
Stay at Peak Efficiency
MAU (Make-Up Air Units) Installations are an integral part of keeping your building operating at peak efficiency. Since Calgary is in Climate Zone 4a, that means that mechanical systems need to be designed and constructed around the minimum temperature of that zone. This also means that the make up air units may need to preheat the air coming into the building – especially in the winter. Climate zone 4a has the extreme minimum temperature listed as -31.7*C to -34.4*C. Bringing in fresh air at such a low temperature may do more harm than good. Preheating the air offsets, the cold air coming in by adding warm air into the stream. For Calgary and area, the addition of hot water, or electric coils to preheat the air is not a luxury, it is a requirement.
While it may seem like the extra parts add money to maintenance costs, it makes your HVAC system more energy efficient by taking some of the load off of your main heating system. If your building is experiencing ventilation and air quality issues, it may be time for a new make up air installation.

MAU Servicing
Filters & Inspection
MAU Servicing should be a part of your annual maintenance plan. Depending on how large your building is, you may need to have professionals service it quarterly instead. Some maintenance managers may be changing the filters regularly but there is much more to the efficiency of a make up air unit than that.
It is important to:
- Change filters every 1-2 months
- Lubricate inlet dampers
- Inspect:
- belts,
- motor and
- communicating components
Inspect your gas-fired equipment components:
- heat exchanger
- vents
- motor
- burner
Preventative maintenance is not only important to maintain the warranty of the equipment, but also proven to get the longest lifespan from your equipment. New make up air unit installations can be costly and interrupt business hours. Not only that, investing in maintenance for your commercial HVAC system will also increase its energy efficiency since restricted air flow can cause unnecessary load for your main heating and cooling equipment. At Caon, we offer preventative maintenance plans that are built to meet the needs of each individual building. Our technicians are on call 24 hours a day/7days a week with priority given to our maintenance clients.
Contact us today to discuss how we can help you make the most of your make up air unit servicing schedule call 403-279-6641 or email info@caon.ab.ca.
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