Some microphones such as condenser microphones require power. A steam turbine often exhausts into a surface condenser that provides a vacuum. Most MEMS microphones are variants of the condenser microphone design. This is similar to the phantom power technique commonly used for powering condenser microphones. River water with pollutants are also undesirable for condenser cooling water. This is not to be confused with the coil condenser. This feature resulted in the Condenser/Capacitor bushing. Final heat rejection was through a water-cooled condenser. Unit 1 had a different, entirely passive cooling system, the Isolation Condenser (IC). The major disadvantages of condenser microphones are their expense and fragility. These turbines receive steam from a boiler and exhaust it to a condenser. Different scales apply for condenser and vented dryers. The capacitor was originally known as a condenser or condensator. A great feature of the air cooled condenser is they are very easy to clean. The simplest cycle consists of a steam generator, a turbine, a condenser, and a pump.