MLRa series custom air handling units expand on the features offered in the MLR units, with an all-aluminum, fully customizable design. This innovative design has reduced lead times, and expanded our capabilities to better handle hygienic and industrial applications.

MLRa units are Flat-Pak certified!

Give us a call to find out about getting a unit delivered broken down on pallets, ready for site assembly.


  • Infinitely customizable design; indoor or outdoor construction, with upgraded materials available
  • Full thermal break; 2” thick double wall panels, with injected foam and no through-metal
  • Easily broken down for transportation or installation
  • Extremely low leakage design, able for high static pressures


  • Full access for servicing components
  • Minimal disruption to existing ductwork and piping, thanks to the ability to match an existing footprint
  • Ease of installation; sections can be made small enough to fit through doorways, etc.
  • Minimal infiltration, exfiltration and radiant heat conduction mean impressive energy savings

We typically include EC Fan Arrays in MLR units.

If there is anyone you would like me to direct some positive feedback to, I'd be happy to do it. It's been a long time since I've experienced service like the entire Mainstream team provided on this order.

Trotter & MortonGeneral Manager

I have found Mainstream equipment built to a very high standard to deal with our demanding applications, while being competitive in pricing. Their sales and engineering staff have been responsive and helpful in making equipment selections and offering solutions to difficult projects.

Cold Spring Harbor LaboratoriesAssistant Director of Facilities

If you utilize them, you won't be disappointed, great communication, good customer service, very good product.

Lackland Air Force BaseHVAC Systems Supervisor

Engineering? Site Assembly?

Learn about the services we offer.

Learn about our MLR Series Semi-Custom Air Handling Units