Enhanced Performance with Payne Indoor Coils No heat pump system is complete without the fan coil. Payne's Model PF4M fan coil supports R-410A refrigerant and our model PF1M fan coils support R-22 refrigerant and are the perfect match with any of our heat pumps to deliver quiet, energy-efficient comfort. Our copper tube, aluminum fin coil provides exceptional heat transfer needed for heating and cooling effectiveness and efficiency.