Video · HVAC Installation Craft
Evaporator Coil Installation in a Basement Starts With a Tape Measure
An evaporator coil installation starts with a tape measure, because the new coil has to match the furnace it sits on. Here a tech measures the existing furnace in an unfinished basement before the new AC coil goes in.
Job footageSwiftPro
- Topic
- HVAC Installation Craft
- Length
- 0:41
- Posted
- September 9, 2025
- Shot by
- The SwiftPro crew, Northern Virginia
What you’re seeing in this video
The SwiftPro box truck is parked outside a brick colonial. Down in the unfinished basement, a bearded tech in a black SwiftPro polo and tan cargo pants stretches a tape measure across the old furnace cabinet.
The AC coil, called the evaporator coil, sits on top of the furnace in a metal case. It's the indoor half of central air, where refrigerant absorbs heat from the air the blower pushes through it. Its width needs to line up with the furnace and its height has to fit under the plenum and ductwork above.
Why it matters in your house
- Furnace cabinets come in a few standard widths. A coil that's narrower or wider than the furnace leaves a gap or overhang that leaks air and strains the blower.
- The coil also has to be matched to the outdoor unit for rated efficiency. A mismatched pair cools, but not at the efficiency you paid for.
- A coil in the basement needs a working condensate drain. Check that the line runs to a floor drain or pump, not just onto the slab.
Can you replace just the AC coil on top of a basement furnace?
Yes, if the coil matches both the furnace width and the outdoor unit, and the refrigerant type is compatible. If your outdoor unit is old or uses R-22, replacing only the coil rarely makes sense. A tech measures the cabinet, checks the plenum height and confirms the match before ordering anything.
Want it done at your place? See HVAC Installation Craft at SwiftPro or call (703) 997-9757.
More videos from the SwiftPro crew
0:17AC Startup Procedure: Weighing In Refrigerant on a New Trane System
0:46Brazing an AC Line Set: The Torch Work on an AC Swap
0:31AC Filter Drier Install: Copper, a Torch and a Wet Rag
0:46Sealing Ductwork Connections, With the Sound Turned Up
0:27HVAC Plenum Up Close: Checking Seams and Sealing Around the Coil
1:23R-454B Refrigerant Install on a Long Line Set, With a Job Site Check-In