Rain Water Harvesting

*WKD*

Just wondering if anyone has had any experience with one of these? Any feedback warmly welcomed - TIA

Tefral

http://www.bnm.ie/environmental/index.jsp?&1nID=113&2nID=128&3nID=134&nID=153&aID=264

Builderfromhell

I'm installing a rainwater harvesting system at the moment.
If you have specific questions you could post here or PM me.

*WKD*

Builderfromhell I look forward to hearing how you/it gets on.

Thanks for the info cronin:)

uptowngirly

Hi Builderfromhell!

A couple of quick questions!

(a) Are you using the water for toilets and washing machines or are you only using it for an outdoor tap for gardening, car washing etc?

(b) What capacity is the tank?

(c) Were you expected to organise the hole be dug for it yourself or was that part of the cost?

(d) If you are using the water for grey water items - do you have some system that if there is no water in the tank that the mains will kick in (I live in fear of livng in a house where people can't flush the toilet if there hasn't been rain in a while - even though it is Ireland!)

(e) What kind of maintenance is involved? eg How long is the expected life of the pump and what kind of warranty came with it?

(f) Any chance you could PM me the company you are using?

I've just read back on the post - and there are quite a lot of questions - sorry

Johnniep

I have spec'd a few different systems and would make the following comments:

(a) Are you using the water for toilets and washing machines or are you only using it for an outdoor tap for gardening, car washing etc?

Check the filter supplied with the RWH unit. Personally, unless you were adding additional filtration I would only used if for flushing of WC's and external use.

(b) What capacity is the tank?

There is a balance to be struck here as you typically design it for the number of days without rain that you expect. Typically, a standard house would have somewhere between 3000 and 6000litres storage. Because we don't know how much water is going to cost, it's very difficult to work out the payback period of the tanks.

(d) If you are using the water for grey water items - do you have some system that if there is no water in the tank that the mains will kick in (I live in fear of livng in a house where people can't flush the toilet if there hasn't been rain in a while - even though it is Ireland!)

There are 2 ways to plumb in a RWH tank. First is to run all WC's from the rising main from the tank. The tank would be fitted with a mains water top up that would kick in when there is a low volume in the tank, ensuring you don't have the WC's running out of water.
The second (and my preference) is to install a second header tank in the attic for harvested water. This was all your taps, WC's etc are for a gravity fed system. Also, with the mains top up going to the header tank, it means that you are not pumping mains water during periods of dry weather, thus reducing running costs, pump life etc.

There are a load of suppliers out there so be sure to compare the spec sheets of the various units to ensure you are getting the best possible unit.

Hope this is of some use.

YourAverageJoe

i had thought about doing this but until water metering coms in it is pointless. I suggests running all of your surface water to one soak pit and then later on you can dig up the soak pit and put in a tankin its place. In reality, how long is going to take to install water meters on every house in the country, 5 years?

*WKD*

Johnnie - great point about the unit must check with architecht/builder on make sure its the best of the best

We are commencing our build soon so makes sense to install now!

uptowngirly

Thanks a million Johnny

That's some amount of research you've done!

IMHO it's not a case of waiting until they start charging for water - it's a small thing that anyone with enough room on a new build can very easily do at a small price - and it saves water which is not all about cost but an investment for future generations.

Any chance of a PM on the system you think is best - pretty please ;)

The only tank I've got a spec for so far is for a 9000 litre tank and they were talking about a price in the vacinity of 2500 for it. (this is before any type of haggling!)

clint_eastman

uptowngirly wrote: »

on a new build can very easily do at a small price )

I've struggled to justify installing one of these systems. I've gotten 6-7 quotes of varying specs and tank sizes and it comes down to the fact that there is a very long pay back period (if any). I tried to convince myself to do it on eco grounds, but the minimum cost for a system including uv filter for shower use is 3.5k delivered (I do not agree that this is a small price), before I have to dig a big hole, plumb and electrics. I'm coming around to the idea that my solar panels fulfill my "personal" eco/renewable needs. IMO there are a waste of time if you do not use the water for hygeinic purposes as well as for toilets etc. I plan on directing all of my roof water to an adequately sized soakpit with the intention of installing a RW system in the years to come if there is some grant available or if water charges become massive (neither of which I see happening in the near future).
I think that they are are fantastic idea but in reality there are just too expensive (for me) at the moment.

*WKD*

I think ours is costing 2k perhaps its a smaller tank? Dont have building price break down in front of me. Ours is defo just for toilets and outdoor use. We are not planning filtration for inhome domestic use. For me it's something I feel is worth doing as part of our build after discussion with architecht etc. Just have not heard any real life feedback yet as they are relatively new.

clint_eastman

Yeah, its definitely personal choice and I commend you for doing it. If anyone is interested I've uploaded some figures of quotes I've received (omitted company names) just to give an idea of the costs. These are for approx 200sqm of roof and include for uv filtration to allow for showering etc which accounts for 40% (i've been advised) of water usage. One quote I got was off the wall,7.5k:rolleyes:

YourAverageJoe

matches the sort of prices i was finding. I even priced getting a conrete tank and installing it now with the rest being added latter but tank was still going to cost 1500 which to me is a lot of money.

uptowngirly

i just re-read my post and I hope I didn't offend anyone by making out that it was such a small amount of money it was a no-brainer on environmental grounds. 2500 is a big amount of money - of course it is - but when you put it beside other costs, it is absolutely worthwhile in my opinion.

My point was 2500 for a new build is only 1% of my budget for a 250sqm house. The plumbing costs are included because, to be fair, you're paying for plumbing anyway and our plumber has said that all he'd need is some extra piping to plumb it in as it was not a big job on a new build. I'm going to afford it by buying all my sanitaryware from the UK.

Building a house, (in the planning stage like we are) is about making choices - what kind of tiles you're going to put down / what kitchen are you going to get / home automation / fancy electric gates / mood lighting etc. We all sacrifice something in order to have enough money to do something else - we prioritise. We have prioritised the rainwater harvesting system for our family - that makes it right for us and I would never suggest that that would follow on and make it right for everyone. I'm really sorry if that was the way my previous post read. :eek:

clint_eastman

uptowngirly wrote: »

i just re-read my post and I hope I didn't offend anyone by making out that it was such a small amount of money it was a no-brainer on environmental grounds. 2500 is a big amount of money - of course it is - but when you put it beside other costs, it is absolutely worthwhile in my opinion.

My point was 2500 for a new build is only 1% of my budget for a 250sqm house. The plumbing costs are included because, to be fair, you're paying for plumbing anyway and our plumber has said that all he'd need is some extra piping to plumb it in as it was not a big job on a new build. I'm going to afford it by buying all my sanitaryware from the UK.

Building a house, (in the planning stage like we are) is about making choices - what kind of tiles you're going to put down / what kitchen are you going to get / home automation / fancy electric gates / mood lighting etc. We all sacrifice something in order to have enough money to do something else - we prioritise. We have prioritised the rainwater harvesting system for our family - that makes it right for us and I would never suggest that that would follow on and make it right for everyone. I'm really sorry if that was the way my previous post read. :eek:

No probs, I understand there was no offence meant and you are completely right to make your choice as you see fit. Like I had said earlier, its a super idea and I would love to do it if it was cheaper. The funny thing is I have a budget for it as from day one I had planned on installing a RWH system, but now that the stage has come to actually buy it and spend the money on it, I can see so much more that could be done with the money which out weigh the feel good factors of the RWH system. Good luck with your project!

*WKD*

Uptowngirly great point in regards to the sacrifices. Building and planning is a balancing game and what's not spent on tarmac will be spent on solar panels for us. My friends just built and have an amazing kitchen all the bells and whistles but now are struggling financially in regards to completion in other areas. So it is defo a matter of choice and RWH is not something I would prob ever consider if i had bought my own home rather than building!

TKD SC

clint_eastman wrote: »

include for uv filtration to allow for showering etc which accounts for 40% (i've been advised) of water usage.

Hi all,

just picking up on this point, does anyone know the %'s of where water is used in houses?!
Above mentions 40% for showers.
Architect told us toilets a/c for almost 70% whereas a builder friend said toilets were about 10%?!
What about washing machine / dishwasher?
Outside hose usage?

Presumably a basic enough rainwater system (without getting into filtering etc) would just be used for water to toilets and maybe to an outside hose.

If toilets are a low enough % of water use then are RWS really that economical, even if they do bring in water charges?

Plus, presumably you still are connected to the mains water for your drinking water?

Another stupid q's: what water would be normally used (say in Dublin city house) for water for washing machines / dishwasher vs drinking water vs toilets - is it all from different versions of "mains" water or how does it all work?!!

We're starting a new build and trying to figure out the whole thing!! Also, where do most people get rid of their rainwater? Our architect is talking about a soak pit, (we are detached house in own site), but what do most people do (again in Dublin city)?!

Last thing in the mix is we're looking into possibility of boring our own well, but equally confused over that vs mains water vs rainwater harvesting system!!

Any answers to any of my many questions above would be really really appreciated!! Getting totally confused and need to decide soon on all these things!

Thanks very much

Simon

Johnniep

Hey ya Simon,

In terms of rainwater harvesting, it is difficult to do a cost benefit on RWH as we don't know how much water is going to cost us so cant help you out on that one.

In terms of usage, the figure I generally use for WC usage in a house is typically 50%. This will be reduced if you use dual flush cisterns but 50% is a nice easy number to work with!

The extent you use the harvested water for should take into account the type of RWH system you are using. If you are using a standard Kingspan/JFC unit, I would restrict it to WC's only. If you start using the water for washing machines etc, you are relying on the filter in the RWH tank to work properly all the time and if this doesn't happen (as there is maintenance required to the harvesting tank which can be easily forgotten!!) you may be using silty water in your machines which may clog internal filters etc and lead to damage, so this should be considered before deciding what to use the water for. The cost for increasing filter quality on the harvesting tank tends to rise quite dramatically so its a question of cost vs benefit.

Using the harvested water for an external tap or the likes is no problem.

On the water supply issue, where are you based as it is very unusual to consider boring a well if mains water is available, but I suppose with water charges looming, it may become more popular.

Hope this helps,

John

tred

Our water is being metered for the last couple of years. its a local scheme, but it has local goverment backup. you pay a fixed charge yearly, for your water, which gives you an allocation of x amount of water. for a normal household with zero leaks, we dont go above this. so thinking down the line your going to avoid yearly water charges totally, this is bunkum youll always pay a standing charge, if you are thinking about setting up a guesthouse, or bed and breakfast, then it might be worth looking into. If it was cheap, and from an environmental point of view, then its a good idea, but then you have another pump running, and the maintenance i am sure of filters etc, so there is a negative that side as well for all us green folks out there!

YourAverageJoe

YourAverageJoe wrote: »

i had thought about doing this but until water metering coms in it is pointless. I suggests running all of your surface water to one soak pit and then later on you can dig up the soak pit and put in a tankin its place. In reality, how long is going to take to install water meters on every house in the country, 5 years?

I have the house RWH ready, as in the toilets are fed via a separate pipe that goes to a tank in the attic, there is also a spare feed pipe to the tank that goes outside waiting for the harvesting tank, there is a space waiting for it next to the soakaway.

I already have a meter fitted, all recent newbuild require them.
So when the water charges come in and start to get steep then I'll finish the job!

YourAverageJoe

YourAverageJoe wrote: »

matches the sort of prices i was finding. I even priced getting a conrete tank and installing it now with the rest being added latter but tank was still going to cost 1500 which to me is a lot of money.

I'm looking at doing it on the cheap, I plan to get a couple or three of those bulk liquid containers link them together and bury them using a weak concrete backfill. they cost about €100 each from the farmers co-op or if you're lucky someone at an industrial site may give them away free!

TKD SC

Johnniep wrote: »

Hey ya Simon,

but 50% is a nice easy number to work with!

The cost for increasing filter quality on the harvesting tank tends to rise quite dramatically so its a question of cost vs benefit.

Using the harvested water for an external tap or the likes is no problem.

On the water supply issue, where are you based as it is very unusual to consider boring a well if mains water is available, but I suppose with water charges looming, it may become more popular.

Hope this helps,

John

Hi John,
Thanks very much for that. If we went with it, don't think I'd bother with the whole filtering thing, just use it for toilets / outside, which if that's 50% of water requirements, then not too bad.
In Clonskeagh, D14, mains water is avail, but looking into possibility of well, tbh not sure how viable this is, and I'd prob favour mains water. Keep it simple!
May be an idea to get linked up and ready for RWH but not install until down the line a few yrs...

Thanks for reply
Simon

paddy147

Deleted User wrote: »

I'm looking at doing it on the cheap, I plan to get a couple or three of those bulk liquid containers link them together and bury them using a weak concrete backfill. they cost about €100 each from the farmers co-op or if you're lucky someone at an industrial site may give them away free!

60-70 euro new off of donedeal.

Carlow52

Looked at the <snip> slimline system today and for an
initial 440 litres of storage above ground in GRP or similar tanks
c/w
RW filter,
1 bar pressure pump
float switch for mains top up ( only to meet immediate demand and not fill tank:)
galvanized wall fixing brackets
it is priced at 1,815 inc vat
additional 220 litre modules to add on are euro 363 inc vat

Its very neat and very much self install but at euro 4.10 per litre is it expensive?

See image attached
ps on 5th
Just added screen shot of a spreadsheet that can be used to 'do the math' on requirements. Its from a supplier and their copyright, if any, is recognised.
pss
From a supplier of this sort of equipment when I added dish-washing as a use

"Be advised that although many people use harvested water for dishwashers, we cannot sanction our system for this application as legionnaires disease although extremely remote can exist in temperate water. "

This certainly makes burying the tank more attractive, based on the temperatures listed here
http://en.wikipedia.org/wiki/Legionellosis

kodo

Hi,

I'm trying to figure out if it's worth installing such a system, but does anyone have any experience with any of the installers/companies? Any testimonials?

Cheers,

Aoife

Carlow52

kodo wrote: »

Hi,

I'm trying to figure out if it's worth installing such a system, but does anyone have any experience with any of the installers/companies? Any testimonials?

Cheers,

Aoife

what do u mean by domestic use?

what I mean where in the house do u want to use it?

kodo

Domestic, as in for Residential use rather than commercial/company/farm. So it will be a small roof area and won't be entitled to a grant.

Carlow52

kodo wrote: »

Domestic, as in for Residential use rather than commercial/company/farm. So it will be a small roof area and won't be entitled to a grant.

Thanks, I am more concerned with the usage, for the garden and toilets RW is fine but after that as noted earlier more filtration due to dirt and more hygiene due to legionnaires risk

Scartbeg

We are putting in a RWH tank right now on our new build.

7500 litre concrete tank + pre-filter + mains top up valve + overflow trap - €2500 from a company in Kilkenny.

4bar submersible pump, pressure vessel, coarse and fine filters + UV treatment another €1100.

Plant is on site anyhow for digging out septic tank so minimal installation cost.

This will feed all house plumbing except for the kitchen tap.

We had applied for a well on our planning, but council water services insisted we connect to their main (which froze up the last two winters)

emese

Carlow5, would you have a link to that rainwater calculation? (where i could fill it out)
We are thinking of putting in a rain water collection system soon (renovating an old cottage) for domestic (toilet, bath, sinks, washing machine) and outside use as well. Know next to nothing about them though... Anyone know what the cheapest option is?? Would prefer above ground - how do you deal with frost then...? Any advice apriciated!

Greenman

A view from Belgium/Vlanderen.

Although I'm not in Ireland I might add my take on this subject.

People here have been doing RH for years because of tap water costs.

In the last few years they made it compulsory to fit an in the ground tank made of concrete if you are building a new house or doing a renovation.

We recently extended the house and placed a 10,000 litre tank €1000 placed in the ground. Two thirds of the roof space flows into the tank with an overflow that goes to the street pipes.

Soon I will purchase a DAB pump €450 that will feed my toilet and washing machine. We use 90 m3 of water per year so it will be interesting to see if that changes.

Finally although frowned upon people bore say 10 meters into the ground and connect a pump and use this water for the garden.

I hope this of interest.

http://www.awouters.be/index.php?option=com_content&view=article&id=50&Itemid=57 If you click on this and use Google Translate there is lots of info.:)