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Cost of Supply Air Plenums

Before understanding the costs associated with buying and installing supply air plenums, homeowners need to know how they function. A supply air plenum is a metal box that can be attached to the outlet of a furnace. It can also be attached to an air handler. These metal boxes are used as a central manifold for all of the ductwork to connect to. When air blows out of the air handler or furnace, it will pass through the supply air plenum and then to the ductwork that is attached to it.

The Costs

  • Minimum: $50 per unit

  • Maximum: $100 per unit

The cost of supply air plenums depends on the size of the supply air plenums that are purchased. Homeowners will need to pay attention to what size supply air plenums correctly attach to their furnaces. If a homeowner is unsure, the contractor hired to install the supply air plenum will be able to assess the system. In general, supply air plenums will cost homeowners between $50 and $100 depending on the size and quality of the unit being purchased.

The other cost for the homeowner to consider is labor for the installation. It is important that supply air plenums are installed correctly, which is why most homeowners should opt to hire a professional contractor. Depending on the company hired, installation costs usually run between $100 and $200. This does not include the price of buying the supply air plenums.


The materials needed to install a supply air plenum vary depending on if the unit is an internal or external unit. Either way, it is usually a good idea for the homeowner to let a professional install it to make sure that everything is done properly. Keep in mind that not all of these tools or materials will be needed for all projects. Only a professional contractor can inform the homeowner as to what materials will be needed.

  • Supply air plenum unit

  • Air curtain supply plenum

  • Back supply plenum

  • Horizontal supply plenum

  • Variable supply plenum

  • Drill

  • Duct tape

Advantages of Supply Air Plenums

The biggest pro to a supply air plenum is that it enhances the function of almost all furnaces. This unit connects the duct work to the furnace itself. Without it, the furnace would be unable to deliver air to the entire house. How often a supply air plenum is going to need to be replaced will differ depending on the quality of the material purchased by the homeowner or contractor, but homeowners who do their research can find low-maintenance units.

Disadvantages of Supply Air Plenums

Because supply air plenums are needed to connect the furnace with the duct work to transfer air around an entire house, some models can be expensive, especially when size is considered. Some furnaces require larger supply air plenums than others. This can greatly increase the cost of installing the air supply plenum. These units are needed for a furnace to function, so the only factor that the homeowner can change to control the cost is the quality of the unit purchased.

Last updated on Apr 1, 2015

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