Repairs, Maintenance and Renovations

November, 1 2023 Published by Golden Horseshoe Chapter - By Kelly Halkett

Understanding The Role and Function of Makeup Air Equipment

From the Volume 17, Fall 2023 issue of the CCI GHC Condo News Magazine

Recent events such as the COVID-19 pandemic and the wildfires plaguing Ontario and Quebec had many managers wondering if they should shut down their building’s makeup air equipment to preserve the air quality inside the building for their residents. Managers might not think about the effect this type of weather or situational events has on this equipment, but it is important to remember the role of the equipment and what it is designed to do.

Makeup air equipment, or MUA as most of us know it, is designed to ensure there is adequate ventilation moving within the building by supplying fresh air to pressurize the hallways and common areas to prevent odours from entering the common spaces and provide air changes required for a healthier and more comfortable space for residents.

In situations when trying to decide if MUA equipment should be turned off, it is important that managers and the Board of Directors are well-informed about local guidelines and recommendations provided by public health agencies or authorities. In addition, ensure that the corporation’s HVAC provider has been consulted to determine the most appropriate measures to maintain a healthy indoor environment while minimizing potential risk as well as having a better understanding of the requirements of the building. However, there are solutions to preserving air quality without shutting the equipment off entirely, such as:

  1. Filter Upgrades: It may be beneficial to upgrade the filters that are being used in the MUA to enhance filtration efficiency and capture a higher percentage of airborne particulates, including potentially harmful ones. High-efficiency filters or filters with a higher MERV rating can help improve indoor air quality during a poor air quality event. In addition to upgrading the filter schedule more frequent filter changes can also offer a benefit to building air quality.
  2. Adjusting Ventilation Rates: If the MUA has VFD control you may be able to have your HVAC contractor adjust the ventilation rates according to the situation may involve reducing the intake of outdoor air temporarily while still maintaining some level of fresh air supply to meet ventilation requirements.
  3. Monitoring Air Quality: Utilizing air quality monitoring systems can provide real-time information about air quality parameters, such as particulate matter levels or volatile organic compounds (VOCs). This data can help property managers make informed decisions regarding the operation of the MUA.

Types of MUA:

The specific type of MUA equipment used depends on the building’s size, layout, ventilation requirements, and energy efficiency goals. There are several types of MUAs that are most used in buildings:

  1. Rooftop units (RTUs) are self-contained HVAC systems placed on the roof of a building. They can be used as makeup air units, providing both ventilation and temperature control for the indoor space. There are limits to how much fresh air can be utilized by these RTU’s before it affects proper operation.
  2. Air handling units (AHU) are large systems that condition and distribute the makeup air throughout the building. AHUs often include heating, cooling, and filtration components to ensure the incoming air is at a comfortable temperature and clean.
  3. Energy recovery ventilators (ERVs) are specialized MUA equipment that not only brings in fresh air but also recovers heat or cooling from the exhaust air, improving energy efficiency.
  4. Exhaust fans with louvers: in some cases, exhaust fans may be used to create negative pressure inside the building, drawing in fresh outdoor air through louvers or openings.
  5. Variable Refrigerant Flow (VRF) systems can also be configured to supply makeup air, offering flexibility in conditioning, and distributing the fresh air throughout the building.
  6. Dedicated makeup air unit (MUA) is the most common for condominium properties and are standalone units specifically designed for makeup air purposes. They focus on introducing tempered fresh air into the building without necessarily providing additional heating or cooling.

MUA Maintenance and When to Replace:

Like all building equipment, when there is a lack of or inadequate maintenance it will lead to problems. With an MUA, if there is an accumulation of dirt, debris, or pollutants in the filters, coils, or ductwork, it can hinder airflow and decrease efficiency or imbalances within the building. By giving due attention to filter changes and maintenance, not only will you promote better air quality, but you will also enhance the efficiency of the system and prolong its lifespan.

Another common maintenance issue for the MUA is the malfunction of the motor or fan. The motor or fan is responsible for drawing in and distributing fresh air and it may encounter issues like motor failure, worn-out bearings, or damaged fan blades. This can result in reduced airflow, noisy operation, or complete system failure.

The life expectancy of the equipment can vary depending on several factors, including the quality of the unit, regular maintenance, environmental conditions, and usage patterns. On average, a well-maintained unit can be expected to last between 20-30 years. However, it is important to note that this is a general estimate and individual units may have longer or shorter lifespans based on specific circumstances. If the unit is reaching the end of its expected lifespan and requires frequent and costly repairs, it might be more cost-effective to replace it with a newer, more efficient model that will improve energy efficiency, air quality, and overall performance.

If there are significant changes in the building’s occupancy, layout, or ventilation needs, the existing makeup air unit may no longer be suitable. Replacing the unit with one that is properly sized and designed to meet the updated requirements is necessary to ensure adequate ventilation and compliance with regulations. The replacement of an MUA is a sizeable project for a corporation to undertake, costing upwards of thousands of dollars depending on the size of the equipment, so management will want to involve the Corporations engineer and possibly even the solicitor with the entire process to ensure the Corporation is fully protected throughout the replacement process.

MUA Advancements:

Over time, advancements in technology such as energy recovery systems (heat recovery ventilators, (HRVs) and energy recovery ventilators (ERVs), are increasingly integrated into makeup air units and can lead to greater efficiency for the equipment. If your existing unit lacks modern features or energy-saving capabilities, upgrading to a newer model can provide improved performance, enhanced controls, and potential energy savings.

Variable Frequency Drives (VFDs) can be beneficial additions to makeup air equipment in certain situations as they can help optimize energy consumption by adjusting the speed of the makeup air fan based on demand. By modulating the fan speed, VFDs enable the system to provide the necessary airflow while reducing energy usage during periods of lower demand. This can result in energy savings and lower operating costs.

However, it’s worth noting that the decision to install VFDs should be based on a careful analysis of factors such as energy savings potential, system requirements, and cost-effectiveness. Consultation with your mechanical contractor is important as they can help you evaluate the specific needs of the building and determine whether VFDs are appropriate and beneficial for the makeup air equipment in question.

As with any piece of equipment at a property, managers should always consult and involve the contractor for the Corporation in decisions regarding the required maintenance, repair, and use of the equipment to ensure that the life of the equipment is maximized as much as possible. To improperly use the equipment or not follow warranty or manufacturer’s guidelines will result in the Corporation potentially spending thousands on unwanted repairs or in the worst-case scenario, early replacement. After maintenance inspections are completed by the Corporation’s contractor take the time to review what was completed and ask the required questions to ensure that you as the manager understand what has been and needs to be completed. By following these important steps, it will protect you from future challenges.

Kelly Halkett is a former OLCM, RCM, working with Naylor Building Partnerships as a Condominium Operations Manager. Kelly’s property management background helps her work directly with property managers bridging the gap between technical and operations and acting as a support for managers with their day-to-day HVAC needs.


This is solely a curation of materials. Not all of this information is created, provided or vetted by CCI. Some of the information is only applicable to certain provinces. CCI does not make any warranties about the reliability or accuracy of any information found in the materials on this website. The information is not updated to reflect changes in legislation or case law and therefore may not always be current and up-to-date. We suggest you seek professional advice with respect to your specific issues or regarding any questions that arise out of the material. We will not be liable for any losses or damages in connection with the use of any of the material found on the website.

Back to Results Back to Overview

© 2024 CCI National