How Refrigeration Coils Work
Refrigeration coils—also called evaporator or DX (direct expansion) coils—cool or dehumidify air by circulating a refrigerant rather than chilled water. As the refrigerant expands and evaporates inside the coil’s tubes, it absorbs heat from the air passing over the fins, cooling (and often dehumidifying) the airstream in the process. Because the cooling medium is refrigerant instead of water, DX coils don’t need a chiller plant—they pair directly with a condensing unit or compressor.
DX Coil Types
Mainstream builds refrigeration coils in several circuiting configurations to match how the refrigerant needs to travel through the coil:
- Face split — the coil is split front-to-back into separate circuits.
- Row split — the coil is split by rows, often used for reheat or dual-source setups.
- Intertwined — two circuits interleaved through the same coil face.
Custom circuiting and construction are available for use with any refrigerant, and insulated cabinet/drain pans are offered for ducted applications where condensate management matters.
Sizing & Replacement
As with the rest of our coil line, a replacement DX coil is only as good as the fit—Mainstream can field-measure the existing coil or work from an approved drawing to guarantee an exact match, and we build coils as tall as 192″, as long as 410″, and as deep as 24 rows when a project needs it. If you’re replacing an evaporator coil, browse our full refrigeration coils and other HVAC coil lines, or send us a photo of the nameplate to get started on a quote.