Video · AC Replacement
Attic Air Handler Replacement, Seen From the Duct Side
An attic air handler replacement should redo the sheet metal around the unit, not just swap the cabinet. This clip jumps from a patched foil plenum and R-4.2 flex duct to a clean new metal box.
Job footageSwiftPro
- Topic
- AC Replacement
- Length
- 0:13
- Posted
- October 16, 2026
- Shot by
- The SwiftPro crew, Northern Virginia
What you’re seeing in this video
The before shot is an attic a lot of older homes still have: a supply plenum wrapped in foil-faced insulation, flex duct hanging off it, and a can of spray sealant sitting right there, which tells you somebody has been chasing air leaks by hand. The flex duct's outer jacket is printed R-4.2.
Then the cut to the after: new sheet metal where the old wrapped box used to be, a SwiftPro decal on the metal and an equipment checkup label stuck on so the next visit starts with the install record. The plenum is the box that sits on the air handler and hands air off to every duct in the house.
Why it matters in your house
- R-4.2 is thin for an attic that bakes all July. Current energy code generally calls for R-8 on attic ducts, so old flex gives up cooling before the air reaches a room.
- A spray can parked near the plenum is a clue. Leaky seams up there pull hot, dusty attic air into the system, and patching them one at a time rarely keeps up.
- If your air handler is 15 years old and lives in the attic, ask the tech to price the plenum and first duct runs with it. Doing both at once saves a second trip into the heat.
Should the ductwork be replaced along with an attic air handler?
Not always the whole run, but the plenum and the connections right at the unit almost always. A new air handler rarely lines up with the old box, and taped seams at that joint leak attic air. If the flex duct is old R-4.2 or crushed, replacing it at the same time costs less than coming back for it later.
Want it done at your place? See AC Replacement at SwiftPro or call (703) 997-9757.
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