Air fan and plenum restoration – dust and biofilm can settle on these units, descaling and applying corrosion control coatings will extend the lifetime of components.


Air fans are a vital component in any HVAC system; these large fans move the air through your system and must be kept in excellent condition to ensure your HVAC system works optimally.

As with all HVAC systems, these units suffer from wear and tear and degrade over time, requiring restoration.

Our experienced team provide our clients with complete fan restoration and painting. We clean, prepare and restore your fan using safe cleaning products and quality paint to return it to its optimum condition.

What is a Plenum?

In HVAC, plenums form a crucial part of the ductwork in any forced air system. Generating hot or cold air is only half of your HVAC system or heat pump’s job. Once it has heated or cooled the air, it must move through ductwork, circulating through your building. After the heated or cooled air circulates through your facility, it returns to your HVAC unit, which draws it in to heat or cool it once more.

Plenums are usually on either side of the fan or heat exchanger and have the critical function of bringing in, distributing, and removing air. They are the air’s first stop after being heated or cooled and last before going back into your HVAC heat pump. Almost all systems have two plenum boxes: the supply and return plenum boxes.

What Is A Supply Plenum Box?

The supply plenum box connects to the supply outlet of your HVAC system and heat pump. It receives the newly heated or cooled air directly from the unit, then distributes it to your ducts to recirculate through your building.

What Is A Return Plenum Box?

The return plenum receives used air from the return vents and distributes it to your HVAC unit to be heated or cooled again. The used air must pass through a filter before entering the return plenum, ensuring it’s clean before reentering your AC, heat pump, or system.

While plenums are not particularly complicated, labour is involved in correctly accessing, extracting, repairing/replacing, and reinstalling them. The cost of a plenum box repair depends on a few different factors:

  • Whether it is the return or supply plenum.
  • What state is the unit
  • Whether your technician discovers any other issues.

If a plenum box is the only repair needed, you need professional help.

Profession care and service

Plenums are deceptively simple, but incorrect installation and repairs can cause significant problems for your HVAC equipment. For example, if a plenum is installed in a way that does not allow for smooth airflow, you might end up with frozen direct expansion coils, tripped furnace limits, failed heat exchangers, and failed compressors.

You can also lose efficiency if the air is leaking from your plenum. Having installation or repair done only by a skilled HVAC contractor will ensure that your plenum boxes are set up to do their jobs without fail.

Trust Air Restore for the best possible outcome when you need HVAC repair.