It is a good question, it has been observed that about 40 litres of water is required for cooling for making 500 mL distilled water which is generally left to go in the drain. To use that water one economic recycling technique has been developed by Dr. Sharma, as stated below:

Recycling water technique (Sharma, 2004) the technique is based on a simple principle that is recycling water in condenser Unit. Sharma (2004) made some modifications in the existing distillation technique by introducing a collection, cooling and pumping devices to recycle water in the condenser tube again and again. The technique is low cost and very effective . The water was cooled first by a simple indigenous cooling technique before it was allowed to enter again in condenser unit (recycling). Cooling technique involved collecting water from the outlet tube of the condenser unit in an earthen pot of about 50 litre capacity put on a cement container filled with wet sand. Once the water is filled in the earthen pot about ¾ of its capacity from the condenser unit it gets cooled. Then it is lifted to a reservoir tank of about 60 litre capacity placed at a height of 4 feet from the earthen pot, with the help of a small submersible motor placed in the earthen pot.The water lifting system has been made automatic by connecting an automatic water level controller with two relays in series. This has made the recycler fully automatic means whenever water level reaches to a definite height in the earthen pot, the submersible motor switches on automatically by the water level controller. Reservoir tank can be used as plastic or earthen material depending on convenience. Cooling is more effective if reservoir tank is also an earthen pot. By this method hot water coming from condenser tube cool down in the earthen pot before it is lifted by submersible motor tank. The process of recycling water in the condenser tube goes on continuously and automatically.