Installing the correct indoor or evaporator coil is essential for getting the highest performance and comfort from your central air conditioning or heat pump system. As indoor air passes through the indoor or evaporator coil, humidity is removed, which creates ‘cooler’ indoor air. For best performance, it is recommended that you install a brand-name coil with a brand-name air conditioner or heat pump system. And as always, brand-name equipment offers some of the best warranty protection coverage in the heating and cooling industry. .