I had the opportunity to observe a strange practice in a hospital where my grandma was hospitalized. 

The hospital uses roof top solar water heaters to enable the patient?s attendants and even the patients to take bath. Seemingly a very good practice as it conserves electricity.

But what I saw was very disturbing. The water travels many floors in the building from the roof top heaters to the end user. So the heated water gets cool when the taps are not flowing and the water stays in the pipeline (unless the hot water lines are well insulated). In the absence of storage buckets, each user allows the water to flow out of the taps till the water reaching the lower floors is hot enough. A huge amount of water gets wasted this way. So the hospital which saves precious lives is unknowingly becoming a reason to kill future lives by depleting the water reserves.

So my dear friends, please check the hospitals, hotels, holiday homes etc who may have installed solar water heaters in their roof tops and heat water in huge tanks.  Especially in places where water is not charged by the local authorities, there will be huge water loss.

The only way is to install a temporary storage tank in each bathroom and then the user can divert the water into the tank till the water is felt to be hot enough and then only the hot water should be drawn out of the taps. Instead of an additional storage tank, perhaps the cold water can be diverted into the flush tank for use in the toilets.

I have "designed" a way as shown below to trap this lost water and use it. Please check in your neighborhoods and post your comments. Thank you.