Condensing Make-up Air Units

Bonus incentives for Condensing Make-up Air Units - Act Now! Details below

Condensing make-up air (MUA) units are the smart way to provide fresh air to common areas in commercial buildings. These high-efficiency units feature high turn-down modulating burners with stainless steel heat exchangers. Choose from three categories of efficiency that include constant speed, 2 speed motor or variable frequency drives (VFD)—a great investment that provides payback for your business year after year.


for Commercial/Industrial new construction and existing buildings

Customer Incentives

  • Constant Speed
    $0.30/CFM per unit
  • 2 Speed
    $0.35/CFM per unit
  • Variable Frequency Drive
    $0.40/CFM per unit
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Bonus incentives exclusively for units over 5,000 CFM

2 Speed bonus - $1,500
per unit on top of $0.35/CFM incentive

VFD bonus - $2,500
per unit on top of $0.40/CFM incentive

Service Provider Incentive

  • $100 per unit

Equipment Eligibility

  • ≥ 90% thermal efficiency for new installations and equipment replacements
  • Incentive applies to units ≥ 1,500 to ≤ 14,000 CFM
  • Buildings with demand control ventilation are not eligible
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Work With a Trusted Service Provider

Locate qualified professionals who are experienced with Union Gas programs. These trusted providers are ready to help you assess the best energy-efficient equipment solutions for your business.

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Apply for Equipment Incentives

The process is easy. Simply complete the online application. After you submit it, a Union Gas Energy Conservation Advisor will contact you within 5 business days to review your application and discuss next steps.

More Information About Make-up Air Units

As a part of a heating, ventilating and air-conditioning (HVAC) system, a rooftop condensing make-up air unit (MUA) is a larger air handler that circulates and conditions 100% outside air.

diagram showing how make up air units work

How Condensing Make-up Air Units Work

MUA units are a common form of ventilation. They introduce fresh air into a building and exhaust building air through multiple exhaust fans located all around the building.

MUA units are located on the rooftop of a building and supply 100% outdoor air. As shown in the diagram, the MUA takes in fresh outdoor air and passes it through a bank of filters and dampers to remove contaminants and regulate the amount of air brought in.

The incoming air can then be efficiently heated by an indirect gas-fired heat exchanger. The heated air is then either blown directly into a building space or it can be ducted to target locations. Where condensing MUA units really achieve higher efficiencies is during the heating season. The heat exiting the building is extracted and during this process latent heat is released and captured. The latent heat is used to preheat the incoming air from outside, saving energy and improving efficiency.


  • Condensing technology offers efficiencies of over 90% compared to the 78%-82% efficiencies of non-condensing MUA units
  • High turn-around feature results in better control and comfort
  • Energy efficiency lowers operating costs
  • Improved air quality creates a more comfortable work environment for employees and customers


MUA units require routine maintenance and inspections. Managers should schedule inspections and maintenance on a semiannual basis with a technician from the manufacturer or service provider.

Building Applications

Most commercial and industrial buildings can benefit from installing a high-efficiency condensing MUA unit including restaurants and commercial kitchens, gymnasiums, auto repair shops, wastewater and sewage treatment facilities, and manufacturing and assembly plants.

Looking for a Trusted Service Provider?

These qualified professionals are experienced with Union Gas programs. They are ready to help you assess the best energy-efficient equipment solutions for your business.

Find a Professional

Have Questions About Our Incentive Programs?

Locate an Energy Conservation Advisor in your area or email us your questions and we'll respond within 5 business days.

Contact Us