Collected rainwater can be used for washing clothes, flushing toilets, washing cars and irrigation. It makes a lot of sense to collect rainwater and store it so that it can be used to keep expensive plants alive during the driest summers, when hose pipe bans are in place.
We also have a rain fall sensor connected to our contextual smart home, so it knows when it is raining. Our smart home also models things like rainfall, how many minutes it has rained in each day (going back a whole month), so that it can make more intelligent decisions.
Rain water can be collected from one or more roof areas. The challenge is usually that the flow can get very high, very quickly and the pipework has to be able to handle the maximum flow rate. Another factor to be aware of is that a lot of moss, leaves, and other debris can collect on the roof and in the gutters. This will be washed down in large volumes after a long period of no rainfall and will quickly clog up any smaller bore pipework.
It's usually a good idea to have rain water diverters that can be manually controlled and when disabled, provide minimal resistance to water going straight into the drainage system. In our experience these kind of kits are totally overwhelmed by heavy rainfall and clog up very quickly.
When your rain water storage tank is full, you need to be able to disable further collection both manually and remotely. Receiving a notification that the tank is full is no use if it happens whilst you are abroad on holiday. For these reasons we are developing out own smart rainwater diverter, which can be intelligently controlled by our contextual smart home.
Before storing rain water it is best to filter it as close to the collection point as possible. This is so that if the filters get clogged up, any overspill can be routed back into the drainage system. We have adopted a 3-tray filtration system using a coarse grid, a medium grid and finally a fine grid. Each tray can be checked, removed and emptied independently.
We use one large storage tank and a few smaller ones to store water and currently have over 1000 litres of rain water storage capacity.
Our contextual smart home has sensors to monitor the water levels in our storage tanks, so that it knows if the automated irrigation system can be used. This is typically done with a float sensor
Depending on how low or high your storage tank is, you can use gravity to distribute the collected rain water or you may have to use one or more pumps. If using a pump, then the quality of filtration system becomes more important.
Our largest storage tank is underground and out of site, so we have used a pump to distribute the water.
