Another form of condensing system is the air-cooled condenser. Absorption chillers are designed to be installed separate from the condensing unit. The reflux flowing downwards provides the cooling required for condensing the vapours flowing upwards. The condensing cylinder was water cooled to keep the steam condensing. The station used river water for condensing steam and cooling. Compressor load is also proportional to the condensing temperature. Some locomotives were designed to recycle exhaust steam by condensing it into feed water. It avoids the steam condensing in the engine cylinders, and gives a significantly higher efficiency. Cooked food processing ranges from roasting, steaming and drying to condensing frying, and boiling. Turbine types include condensing, non-condensing, reheat, extraction and induction. A curved reflector redirects light that would otherwise be wasted toward the condensing lens. The higher efficiency of operating in the condensing region isn't always available. In icing conditions, water droplets condensing on a wing's leading edge can freeze. This was done by condensing urea with diethyl malonate. Felt is a textile material that is produced by matting, condensing and pressing fibers together.