A condenser coil is the outdoor coil of a central air conditioner, wrapped around the compressor inside the condensing unit. Hot, high-pressure refrigerant releases its heat there as the condenser fan pulls outdoor air across the aluminum fins, and the refrigerant condenses back into a liquid before returning indoors. In a heat pump, this coil also absorbs heat in winter.
Why it matters to you
When grass clippings, cottonwood, dirt or bent fins block the coil, system pressures and electricity use climb and the compressor runs hotter.
Practical guidance
Keep about two feet of clearance around the outdoor unit and trim plants back. With the power off at the outdoor disconnect, rinse the fins gently with a garden hose, never a pressure washer, and leave chemical cleaning and fin straightening to a tune-up.