Rain Water Harvesting

Benster wrote: »

Would the likes of a weed-suppressing fabric as used in the garden be any good? A couple of layers would probably be enough to cover any small holes those fabrics usually have for water drainage.

You should probaly be thinking of some sort of insulating layer for around the whole tank anyway, kind of like a lagging jacket. A week of snow and low temps might be enough to freeze it enough to cause damage. I'm planning this for my own tanks. I'm also insulating the pipe from the tank to the attic with some Kaimann foam from a plumbing suppliers; the pipe is running up the back wall of the house so will definitely be affected by frost is not covered.
HTH.
B.

That material could be a good idea, I read that pond liner has been used too, it might be better in that I assume its not permeable to water. I'd prefer if I can source it in a builders providers, I read theres a place in or near Naas that does farm supplies and is a DIY place that does stuff at good prices, not sure of the name or location, I think just off from the globe, if anyone knows where Im referring to, please let me know or reply in the thread.

The insulation could be a good idea, Not sure how frequent a problem it could be, in the event there is extreme cold weather, Id like to be able to turn off the system and drain down the outside filling pipes for overnight, I dont think there would be as much of an issue with pipes used to source and drain harvested water as there wouldnt be any water in them overnight if it went cold. In those situations, Id like to be able to operate it manually, fill up, shut off and drain down again, until the weather.

The possibility of having really cold weather even once a year wouldnt justify trying to implement anything to automatically account for this as I haven't even got started on implementing the harvesting, but I wouldnt rule out having a frost stat in it to prevent pipes bursting from even moderate low temperatures.

To do it automatically would be good, but then I would need a number of some kind of small powered valve, that could be directed to open automatically to drain the system if frost was detected. It would be good if there was something smaller and cheaper in 12v than the type used for plumbing systems as they are quite big. Pnuematically operated would just add another layer of complexity and its own valves.

I dont think the tank would freeze? especially if some sunlight was able to shine over it, Id be more concerned about the piping and at bends/junctions.

What are your opinions/ideas for the harvested supply water to the storage tank? I was thinking that just having the open end of pipe flowing in isn't great, I'd thought of having some kind of a ball valve, simpler and the potential to be less problematic regarding failure.

I also may have mistaken what people meant by float switch, I thought people were suggesting one of those switches that floats like on some of those pumps you see in lidl. I think people might have meant something that mounts into the tank inside wall and is activated when the water level reaches and passes its position.

Benster wrote: »

Regarding float switches, this is what I am referring to:

http://www.reuk.co.uk/buy-FLOAT-SWITCH.htm

BTW, that REUK site is a goldmine of info for RWH.

As for the RW supply, at the moment my supply pipe is terminating at a simple tank connector, nothing else. It will just dump into the tank at the point where it is mounted. I must stress that none of this has had water through it yet, so I may have to modify that to maybe put a calmed inlet on it instead.

Is that what you were wondering about regarding the supply?

Good link, I actually found that site already and I realised that they are float switches and this was what I was talking about, but I was wondering if someone (maybe you) had mentioned about float switches and was referring to the type that are attached to motors like some of the ones you see in Lidl.
I was looking at their sensor they have as a DIY, with the coils of wire.

That site has some good info on circuits too, I was weighing the possibility of doing some of the control side of things in 12v and have relays to operate a motor, or even to switch on a pump on a circuit that has a solar charged battery.
I was thinking of collecting grey water too, but there may be enough in rainwater, the greywater side would complicate things more, I was looking at slow sand/gravel bed? filters but I think it would be too slow and they'd be ineffective at dealing with a large volume of water if arrived in one go.
Neither do I have the room to have loads of water storage and a sizeable tank would have to be kept away from the house where there is some unused space, meaning, Id have a bit of pipe and wiring work to do and trying to figure how to pump from it to the attic.

As for the open ended pipe from the HRW, not sure how that would best be terminated, a calmed outlet would mean submerging the outlet there? at that point Id have thought the water is sediment and carbon filtered and maybe even had UV on it, so I thought the calmed inlet was for where the water was collected initially?

Not sure on a first flush system either, as again the filtration would be in place. Id expect to have a few mesh strainers to get out the bigger contaminants, like leaves,twigs, anything dropped on the roof by birds, clumps of moss and then the sediment and carbon filter to catch and contain the rest.

Whatever I do on the control side Id like to have most of the electrics in one place in its own enclosure, with the minimal amount outside that.

Chemical Byrne wrote: »

You shouldn't use the harvested water for your hot water requirements unless you've it treated to a fairly good degree. You must remember that all the bird sh!te and whatever other gunk off your roof will be dissolved in it and a lot of that isn't filterable.

Filtered raw rainwater is only good for outside use and for flushing toilets.

Even that considered, by the time you've factored in the cost of equipment, operation & maintenance and most importantly, your time, the extra little bit on the water bill will be looking fairly attractive.

Did a few quick calcs on this in college, for your average home the payback on the equipment capex was something like 6 years. That doesn't inlcude time spent fooling with it or, obviously, operation & maintenance costs. Basically, domestic RRW has no cost benefit, ergo, it's a waste of time and money.

Personally I wouldnt use harvested water for anything other than flushing toilets/garden/washing car and for toilets only after Id strained and filtered it and possibly UV treatment, although maybe not RO.
Toilets I think is was where the biggest consumption and waste of a large volume of potable water is, I saw someone do a study on it in college myself, it was something like 2/3rds of all the water useage or maybe even greater.
That said, water is water and it can be filtered and cleaned like any water can for any purpose, whether or not it would be worthwhile to go to a potable standard in a domestic scenario or not is another thing, I think not.

But I disagree that it is not worthwhile or that its a waste of time and money to harvest to use in water the garden, washing the driveway/car and flushing the toilet, as vast quantities of potable water are wasted this way.
Despite the fairly large costs I see proposed to instal a rainwater harvesting system by private operators, a competent (or even an incompetent) DIYer could cheaply install a system to collect rainwater, I dont know why the Govt doesnt have a private funded body to come up with efficient free standardised designs but not solely along the lines of water harvesting to promote sustainability (ie pump sizes/components/wiring requirements for those less in the know) and let people get to work at it themselves as much as they are able.
They fund enough other quangos and shyite. This obviously falls foul of their own outlook and agenda, namely tax and vat revenue and of course any real view on actually conserving water, as the less you consume the less you will pay (for now).

The more people conserve and store water, the greater the buffer this provides for the existing system as people are taking less out, ie only to drink/cook and the less cost should need to be spent upgrading it to increase capacity.
Ive read it could even act as a means to prevent certain flooding/or at least reduce the strain on surface water drainage in times of lots of rain (Ive seen something like this mentioned regarding abandoned houses in the US and basements), while not as significant an issue here, if a means to prevent large voulmes of surface water otherwise wasted being dumped into drains and rivers and sometimes sewers where people can put it to use, but if a lot of people could store even a fraction of run off (which is greatly contributed to not being absorbed by soil due to large swathes of concreted/tarmaced/roofed surfaces) water especially in affected areas then it might have other advantages.

Ive yet to get around to doing it myself, as Ive a host of other jobs to do, but once any cost benefits run out, I see no harm in doing it, even if its only break even or barely, its a sustainability and management concern

What do you mean by RRW? I did a quick google to see was it an abbr or acronym for something but it turns up nowt.

I agree about the flood control really but it can be of no harm as a consideration, anybreuced volume of water getting into the drainage system can't be a bad thing, but more particularly because reduced demand on the potable supply by reducing the volume flushed in low flow and by using harvested water means less money has to be invested on upgrading capacity.
Although I think there should be a huge response to fixing leaks in the supply side, I also believe there should be good support to reduce the demand and for very little cost support retro fitting of lower flow equipment in older cisterns rather than outright replacement and also for rainwater harvesting.