Browse Forums Eco Living Re: yet another rain water setup questions 21Jun 10, 2015 10:46 am Ok so running through the calculator I get this for possible max and min head depending how full tank is. will be using 50mm rural poly. With 50.8 internal diameter? also the dual float switch in tank I was looking at a 50mm Apex Bigboy setup in the rainwater harvesting mode is there something else that could be suitable? Re: yet another rain water setup questions 22Jun 22, 2015 1:59 pm I have just read back through everything to refresh my memory and it is clear that you have a good grasp on best practice. You stated that you intend using the bore water tank for the toilets and irrigation as well as collecting the overflow from the rainwater tanks. One mistake that people make is assuming that the water harvested from the roof/rooves equates to 100% of the rainfall and you will see this in many websites where they state that 1 mm of water on 1 sq m = 1 litre. When it is raining steadily, this is for all practical purposes correct but evaporation and other losses reduces the yield considerably. I am in the Melbourne metro area and I advise people here to use an 85% yield as a generalisation as to what to expect their yield will be and much less again if first flush diverters are used. This generalisation is based on statistics that show about 39% of Melbourne metro days have precipitation and nearly 40% of those days have falls of 2mm or less and every rain day results in evaporation and other losses, particularly when there are intermittent showers during summer. The Alternative Technology Association (ATA) have their Tankulator that you can use to roughly calculate your expected annual usage and your annual rainwater 'harvest'. From memory, the Tankulator uses 80% as the yield figure but you will need to check this. Im Melbourne, a system with a first flush diverter will commonly produce yields of about 50-65%. When using the calculator, also remember that annual rainfall varies greatly, Eastern and South East Australia is currently in an unofficial El Nino and heading into an official El Nino. This makes having a sufficient storage capacity very important and you will definately need a second rainwater storage tank. http://tankulator.ata.org.au/index.php The bore tank's pump size is something that I can't really advise on because I don't know what sort of irrigation system you intend having and the flow rates you envisage needing. The toilet cisterns are a low flow rate requirement, approximately 6 lpm, and you don't want a big pump supplying a cistern as it will choke the pump and use a lot of energy. For this situation, I always suggest having a smaller pump and a pressure tank. Pressure tanks can be located away from the pump and having a remote pump supply a pressure tank at the house means that the pressure tank has less friction loss between it and the fixture. You can buy a 60 litre Davey pressure tank for about $210 and this will give a draw down of about 17 litres but the draw down depends on the tank's pressure setting and the pump controller's pressure setting. There is a fair bit of discussion about pressure tanks in the "Rainwater tank 101 for a new build?" thread. The thing to remember is that the pressure tank's pressure is adjustable but the controller must match the pump to the tank. As an example, a pump with a 60 psi head could be fitted with a manual controller set at 35/55 cut in - cut out settings and the pressure tank would pre pressurised to about 32-33 psi so that the pump starts before the tank runs out of water. The tank's higher pressure would give less draw down than if the pressure was lower and the manual controller was set at 20/40 cut in - cut out but the lower pressure setting will also give a greater pressure (flow) variance when in use. This is why it is wise to have a powerful pump (a greater head rating) supplying a pressure tank if the tank also supplies a shower....or else have a variable speed drive pump. viewtopic.php?f=35&t=72564 Re upsizing from 32mm rural poly to 40mm rural poly, some of the manufacturers graphs are a bit hard for lay persons to understand, charts that show the friction loss per metre are easier to grasp but they are not as accurate as graphs that show friction losses over 100 metres as the one you linked or even a 1,000 metres. An upsize will naturally result in reduced friction losses but it is often a judgement based decision similar to diminishing returns. The graph above is for rural poly pipe and it is a bit clearer than the one you linked. You first need to look at your anticipated flow rates in 2 blocks, the most common and the highest. Let's assume that these are 6 lpm (inside tap) and 30 lpm (2 x showers, and a dishwasher). If we look on the bottom of the page at the 0.5 litres per second point and then travel up the page to where it meets the 1 1/4" pipe line, you will see that this point corresponds with 18 metres head loss per 1,000 metres in the left hand column. If we then do the same thing to intersect the 0.5 litres per second line with the 40mm (1 1/2") pipe, we see that the head loss is about 7.5 metres, a friction loss saving of 10.5 metres over 1,000 metres. This gives us a friction loss saving of 0.42 metres (4.1 kPa) if you upsize a 32 metre rural poly pipe to a 40mm over a 40 metre run. A pump specialist should be able to tell you the best pump for your needs if you can supply him with the house plumbing diagram but I still recommend that you look at the Grundfos variable speed drive pumps. A suitable one will cost you in the region of $1,300 but your alternative could see you with a $700 pump that wasted energy or else a pump and a pressure tank that would give energy savings but not the constant delivery that a variable speed pump would. A pump's flow graph simply lets you determine the expected flow rate at various dynamic heads. The dynamic head is the pump's static head rating less friction losses. Don't forget to include friction losses through any filters if fitted. A pump specialist will require all information. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: yet another rain water setup questions 23Jun 22, 2015 7:13 pm SaveH2O A pump specialist should be able to tell you the best pump for your needs if you can supply him with the house plumbing diagram but I still recommend that you look at the Grundfos variable speed drive pumps. A suitable one will cost you in the region of $1,300 but your alternative could see you with a $700 pump that wasted energy or else a pump and a pressure tank that would give energy savings but not the constant delivery that a variable speed pump would. I have one of these pumps that SaveH2O is talking about. It's an ESybox pump that Grundfos sell. I did have one problem with mine, where a gecko thought it would make a nice new home for itself, and shorted it all out. Grundfos replaced the pump with a new one, and the pump shop I got it from recommended I close up the vents with flyscreen mesh so that I won't get any of his mates trying to call my pump their home. Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: yet another rain water setup questions 25Jun 22, 2015 9:21 pm Because variable speed drive (VSD) pumps have a 'soft' start, they require a pressure tank to provide water instantly while the pump spools up. Pumps manufactured with VSDs will have a small pressure tank already fitted. Energy savings comes from the pumps running slower most of the time. While the VSD pumps are expensive, the cost of the same pump without a VSD but connected to let's say a 100 litre pressure tank will only be maybe $300 less but because the VSD pump delivers a constant pressure at the flow demand, many people prefer to have a VSD pump when the house has no mains pressure water connection. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: yet another rain water setup questions 26Aug 27, 2015 9:51 pm just an update slabs poured but got hit with a massive extra for foundations so have cut alot of stuff back. that also means normal pump. and very small pressure tank will still be doing sediment traps but that's about it until i get some more funds Re: yet another rain water setup questions 27Nov 25, 2015 9:04 pm tanks just delivered needing to sort out some flexible hose for the tank to pump. where's the best place to buy some of that pond flex hose? im looking for 40mm and would need some hose clamps are there special ones for that type? Re: yet another rain water setup questions 28Nov 25, 2015 10:49 pm Clearpond Pondflex hose is available at most irrigation stores. They will usually have rolls of different sizes that they will cut to length for you. http://www.clearpond.com.au/products/al ... ccessories We use it mainly to connect to a wet system low restriction inlet. I don't know what the pressure rating is and I have never used it to connect a pump to a tank, that is something that you would need to check. What length of hose would you be looking at? The 40mm Pondflex is expensive per metre. Blue Stripe poly pipe is the usual choice for your intended use. Note that Blue Stripe is measured as an outside diameter (OD) and comes in different pressure ratings. Your requirement would have an internal diameter (ID) of about 35mm. You might find it difficult to find an irrigation store that will cut a Blue Stripe roll to size but if you require a reasonable length, then it may be cheaper to buy a roll because they usually charge more per metre when they cut to size. I think that the 40mm Pondflex has an ID of 38mm but I am not sure, you would need to check. The spiral clamps are shown in the link I have pasted. I assume that reducing friction losses over a long run is your focus, have you considered using 32mm pipe? Most house fixtures are low flow and the 32mm Blue Stripe pipe you would require has an ID of about 28mm due to it's wall not being as thick as the 40mm pipe. A bit of news about the leaf diverter that I am working on. I have developed a superior 500 micron aperture, high yield, low maintenance filter but the body's design has not yet been finalised. It has proven to be more challenging than anticipated to keep the body as small as possible when using our filter but we are still hopeful of proceeding to manufacture. The project however is behind schedule. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: yet another rain water setup questions 29Nov 26, 2015 6:22 am If that's the case can i just use 40mm rural poly? as between tank and pump only has tank volume pressure. where blue line is pressure rated and cost more I thought I would need to use something a bit more flexible especially for plastic tanks good news your leaf diverted Is getting there. Good things take time. can't wait to see it in production. Re: yet another rain water setup questions 30Nov 26, 2015 2:02 pm The blue line fittings are cheaper but you won't be using many. The rural Green Stripe is also measured as ID and so the nominal diameters for both pipes are not strictly comparable. Flexible couplings/hoses should always be used. Still have the fingers crossed on the leaf diverter, it will make a big difference but there are no guarantees at the moment. If it can't be kept small, it won't be manufactured. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: yet another rain water setup questions 31Jan 22, 2016 6:32 pm ok so things are getting very close to move in. what a hassle i have had with everything! builders plumbers the bank it just goes on just can't take a trick . I have a few check valve (non return valve, one way valve) questions is it normal to have a check valve straight after a ball valve from the tank? - must there be one there? the only reason i can think of is to keep the pump primed is it normal not have a check valve at the house where the ball valves are to switch between bore and rainwater for the house? This means - if both taps are accidently left on i can basically push bore water backwards through the dedicated rain water pipe and contaminate the rain water (drinking) or push (precious) rainwater back through the bore pipe and will go to anywhere the pipe runs eg. outside watering and irrigation ie. waste it. - say i accidently cut a pipe anywhere after the check valve on the pump (so basically any piece of pipe) i can lose all water out of the house, hot water and tank as there's nothing stopping any of it from not returning (i can understand i cant stop the tank from losing water but a well positioned check valve could stop everything else) i cant see that as a good design also i dont have a check valve on the hot water system i can see theres one on my old house. I thought it was required? - that means that turning the water off and draining a cold water pipe can drain the whole hot water system imo i need 3 check valves they have installed 2 of which both appear to be in the wrong location and one on the HWS am i correct or have they done the bare minimum required by australian standard? Re: yet another rain water setup questions 32Feb 01, 2016 12:03 pm B-Man is it normal to have a check valve straight after a ball valve from the tank? - must there be one there? the only reason i can think of is to keep the pump primed If the pump isn't flooded and the tank's water supply can drop below the level of the pump, then a check valve should be fitted. People have also had unexpected high water bills when an automatic switching device has pushed mains water back into the tank and the tank has then overflowed to the stormwater. A check valve should prevent this. Your other questions are plumbing questions, I am not a plumber. Some councils also over-rule some plumbing regulations or add additional mandates, therefore I am reluctant to give an opinion, particularly in the absence of diagrams. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: yet another rain water setup questions 33Feb 26, 2016 1:10 am Hi all from Argentina.. first, sorry for may terrible english.. need advice with my case.. rain water not for consuption use. Very good forum.. And SAVEH2O.. you re a god... hope answers Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ [img][img]http://s22.postimg.org/6tt3ou7ot/WET.jpg[/img][/img] Re: yet another rain water setup questions 34Feb 26, 2016 7:08 am Hi guillote 1.I recommend you start your own thread 2. only 1 image is showing? was there more? 3. what are you trying to achieve? 4. that seems like an awful lot of roof space for 1 51mm downpipe. 5. I recommend you read the first few posts in this thread as I tried to make it easy for someone to copy it and fill in there own information Can a plumber put a tap on a rain water tank which is full? Tank is similar to one in photo. Cheers. 0 1658 Hi, does anyone have any experience with using Trex rain escape or EPDM rubber to waterproof a deck so you have dry space underneath. Popular in the US and realize that… 0 3418 Yes you are correct, unless there are outside works which form part of the contract such as landscaping or driveways, and importantly, the work delayed is on the critical… 1 3505 |