Science Buddies: "Ask an Expert"

Hi,

I am required to create a prototype on how to conserve water. It would be best that this consists minimum coding and sensors used. Currently my idea is to put motion sensor in shower head such that when it detects someone, water will flow out and when the person walks away, the water will stop until it sensed motion again. However, I find that this is quite a simple one.

Need ideas on how to improve or any new suggestions for this project?

Thank you!

Mayhem,

Welcome to the forum. An interesting project. I think there are several ways to enhance your idea (which has merit). Part of making this a science project would be to analyse the full cycle of water usage during a typical shower and identify where the most waist is occurring under various conditions (i.e. identify dependent, independent and control variables to then conduct experiments against).

The objective as I see it is the reduction of waist water. You hit on one element, which is water running when no one is using it. But let's look at the reasons  (or at least one). I don't like to get into a cold shower, so usually have to spend some water just letting the stream warm up to a comfortable temp before getting in. A user would likely look to defeat the sensor to achieve this, unless there were a guarantee that upon initial entry to the shower you wouldn't be hit with an ice cold stream...or scalding hot for that matter either. So some way to ensure the water temperature is pre conditioned so to maximise the in use time and minimising waist. On the other end of the cycle you could look at ways to capture and re-purpose the grey water, which doesn't prevent it's initial use, but doesn't let it go to waist by recycling it for a second use.

Just a few thoughts to spur your own creativity. Good luck.

Hi theborg,

Thank you for the reply.
Honestly, I am not sure if I am required to go towards the science direction since I'm in an engineering course. The aim for this assignment though, is to conserve water usage without compromising human comfort. The current idea that I had in mind requires a solenoid valve to be connected to the motion sensor. But I am just not so sure how to go about connecting them together.

This assignment will be due in a few weeks as well and I don't think there is sufficient time for me to analyse cycle as well as for the greywater part, which is a great idea and I might use it for my capstone project next time. But for now, all I want to achieve is a simple prototype which can help to conserve water.

Mayhem,

Ok, engineering with the objective of water conservation whilst maintaining user comfort. For your idea I think this drives you to pre-conditioning the water so that it near immediately comes out at a comfortable temp. How about heating elements along the feed line from the hot water tank to the shower that would keep the water in the line warm when not in use? You should be able to calculate the amount of heating coil you would need to keep water at a comfortable 25 or 30 deg C or so. I'd attach the solenoid valve in line between the facet valves and the shower head with the motion sensor placed in a convenient way. That way, if the motion sensor opened the solenoid when no one was in the shower it still wouldn't run, you'd have to have the faucet valves open AND the motion sensor active for water to flow and you'd only need one solenoid.

Hi theborg,

Once again, thanks for the reply! Really appreciate it.

I like the idea of placing the solenoid valve in between the facet and shower head. It's something that I had not considered before. It also sounds like minimal coding(hopefully) since only the motion sensor and solenoid valve is used. My group and I are going to do out the prototype in a few days, using those mineral water bottle to replace the shower head and pipe since we can't possibly get a real shower head... But instead of water bottle, I'm wondering if there is any other materials more suitable to use as showerhead?

Mayhem,

Since I'm not sure about your situation and why you wouldn't have access to an actual shower head, I'm going to assume it's funding...you just don't have the ability to buy new components. But if you have access to call and/or visit companies, you might find that they are way more agreeable to offer help than you'd expect. If you explain you are a student looking to build a prototype for an engineering project and were looking for advice on where to get the components you need (shower head and piping) you might be surprised at the help you receive. You might find there are material these places have or can put aside for that they would otherwise dispose of. They might as well give it to you. Be prepared to make many calls to several companies, for your purposes I'd target plumbing, hardware stores, and home building companies. Ask for a manager when you make contact. Also, ask friends and family for help if possible.