Browse Forums Eco Living Re: Another Rainwater Wet System Thread 2Feb 09, 2021 10:31 pm 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: Another Rainwater Wet System Thread 4Feb 11, 2021 2:37 pm 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: Another Rainwater Wet System Thread 7Feb 19, 2021 12:38 am 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: Another Rainwater Wet System Thread 8Feb 19, 2021 9:25 am SaveH20 A 50mm inlet is usually plenty big enough but I am thinking that a 65mm inlet would be better insurance in this situation. You could use a 100x65mm 45 degree junction to branch the smaller pipe. Sounds reasonable, I'll see if I can make that change to the tank. They will be getting sick of me changing my options by now. SaveH20 You require a 20,000 litre fire fighting water reserve, I assume this requires a 65mm Storz outlet. Yes/No? Is there a set maximum height above the bottom of the tank that the valve cannot exceed? Yes, correct. The reserve level will be ~500mm up the tank wall, this is where the pump outlet will be located. The tank salesman was convinced that I could not fit inlet valves within this reserve area of the tank so the extra inlets were optioned at the pump takeoff height also. However I phoned the local RFS and they advised as long as they were only inlets that they did not have an issue wherever they were fitted so I will be getting them positioned 150mm above tank base. SaveH20 If the two 100mm pipes were kept separate, the pipe serving the smaller roof section would be ok but a 40mm inlet would still be beneficial in reducing the water retained in the downpipes and riser as well as having the benefit of oxygenating the heavier density water at the bottom of the tank I'm thinking of branching the two 100mm pipes together to help balance flows between the two roof sections and reduce frictional losses due to excessive flow rates. I was only planning on having a single low inlet for the 2 x 100mm pipes from the house and a second one to service the shed stormwater. As you mention above it may be best to make the house inlet a 65mm valve. SaveH20 This also means more friction loss. I would leave it as is and possibly look at a quick fix at the house itself if necessary that could involve diverting excess water from the gutters to a smaller tank at the house or other measures already mentioned. The former could be done by utilising 50mm inverted nozzles to regulate the height of water in the gutter.. This sounds like more surface run pipes to me, as well as an extra tank near the house? Definitely something I'm trying to avoid to be able to get the balance between function and aesthetics. If I connected the 2 x 100mm pipes to a single 150mm pipe run for the extra distance then frictional losses would be minimised. It would mainly be the extra fittings contributing. An 18m length of 150NB pipe flowing at 1081lpm would contribute ~100mmH2O in pressure losses. So effectively I could achieve an extra 1000mm head while sacrificing potentially 2-300mm extra frictional losses. It will cost a bit more upfront but I'm thinking more and more that it may be worth it to save potential long term pain. SaveH20 Will the riser discharge above the tank's walls i.e. will it be above the roof? Yes it will be above the tank wall height. So height from base of tank to discharge centreline would probably be ~2.3m. This would place it ~400mm below the eaves, something I get more concerned about everytime I think about it. SaveH20 The bottom line of course is that water must pass through mosquito proof mesh prior to entering a tank and you need to have low restriction inlets. I can't say "Yes, give it a go" because there is the possibility of it not working to advantage during a sudden downpour and I don't want to be the one who stood by and encouraged it. Yep this i where the problem keeps coming back to haha. Even if I was happy enough for the gutters to overflow during heavier rain events when the water tank is already reasonably full, I still need to find a workable solution to exclude mozzies. If I leave the tank in it's currently planned location then I can't see that I have any other option but to use the retractable mozzie stoppa style mesh at the downpipes to screen for insects. If they were to be an epic failure due to restriction of flow and buildup of material, which there is every chance they could be haha, then I'm leaving myself with no simple fix aren't I? If I can increase the height differential then at least I have the option to fit traditional leaf diverters if these were to be a failure. Also speaking of overflowing, in your experience have you been able to identify a rule of thumb style guide to what sort of rain inflows standard quad guttering can handle before they overflow, regardless of the resistance in the downpipes and stormwater system? I imagine this is a possibility as a 115mm gutter cant transfer an infinite amount of water. Would be a good rough figure to have, although I'm sure near impossible to get, as then we would know a ceiling limit to design to. Thanks again for all your help SaveH2O. Re: Another Rainwater Wet System Thread 9Feb 24, 2021 1:54 am therobbo SaveH20 A 50mm inlet is usually plenty big enough but I am thinking that a 65mm inlet would be better insurance in this situation. You could use a 100x65mm 45 degree junction to branch the smaller pipe. Sounds reasonable, I'll see if I can make that change to the tank. They will be getting sick of me changing my options by now. But can't you use the 65mm Storz inlet if the inlet line can be easily uncoupled? Your firefighting reserve usually requires a 65mm Storz valve. therobbo The tank salesman was convinced that I could not fit inlet valves within this reserve area of the tank so the extra inlets were optioned at the pump takeoff height also. However I phoned the local RFS and they advised as long as they were only inlets that they did not have an issue wherever they were fitted so I will be getting them positioned 150mm above tank base. The salesman is wrong, he obviously couldn't get his head around a valve being used as an inlet and not exclusively as an outlet. That is funny. therobb0 I'm thinking of branching the two 100mm pipes together to help balance flows between the two roof sections and reduce frictional losses due to excessive flow rates. If they run parallel, could you merge them to a 150mm pipe? therobbo This sounds like more surface run pipes to me, as well as an extra tank near the house? Definitely something I'm trying to avoid to be able to get the balance between function and aesthetics. I agree. It isn't something to consider now because there are workable options, just something that 'could' be considered later if for some reason the better options were overwhelmed. You can also use a sediment trap as an emergency relief outlet during a high intensity rain event. therobbo If I leave the tank in it's currently planned location then I can't see that I have any other option but to use the retractable mozzie stoppa style mesh at the downpipes to screen for insects. If they were to be an epic failure due to restriction of flow and buildup of material, which there is every chance they could be haha, then I'm leaving myself with no simple fix aren't I? If I can increase the height differential then at least I have the option to fit traditional leaf diverters if these were to be a failure. There is a larger Mozzie Stoppa Advanced Max Flow that can be plumbed into a 90mm downpipe. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ https://youtu.be/bG-0UdnTkNQ https://youtu.be/R_L9rqBIZCU https://www.youtube.com/watch?v=8U9T1avFULY&feature=emb_rel_end I haven't been able to find a price for the bigger one plus couplings or even find them for sale. It would try this but have a spare screen to save having to get up and down the ladder more than once. Re restriction of flow caused by the mesh itself...Water passing through mesh at the top of the downpipe is not a consideration if considering possible friction loss but having six 90mm downpipes discharging into a 100mm carrier pipe is. I haven't been able to find any references to friction loss for DWV 88 degree tee junctions. There is a slight curve at the branch and so the friction loss through the run isn't the same as 'square' tees as used in the various flow loss tables. The tee however reduces the downpipe's effectiveness as a 'booster pump'. Sometime down the track I will set up a test using either 40mm or 50mm DWV fittings and conduct tests for pressure and flow rate changes at varying tee and 45 degree wye junction intervals. I have not been able to find any experiments done with spaced downpipes and this surprises me, everyone uses just the one head source. Low inlets assist flow and I have often seen them successfully stop leaf diverters overflowing during heavy rain but the additional head gained between the tank's water level (above the bellmouth's crest) when full and half way above the riser's discharge invert is still unknown. With there now being only 400mm between the riser and the gutter's sole, I am not 100% confident of the wet system draining six downpipes once the tank fills during a storm without knowing the air gap height above the bell mouth. You need to factor a flow of at least 700 lpm as a bare minimum to allow for even minimal wind driven rain. There are a number of flow calculators online, the one below is simple to use. https://www.omnicalculator.com/physics/pipe-flow therobbo Also speaking of overflowing, in your experience have you been able to identify a rule of thumb style guide to what sort of rain inflows standard quad guttering can handle before they overflow, regardless of the resistance in the downpipes and stormwater system? I imagine this is a possibility as a 115mm gutter cant transfer an infinite amount of water. Would be a good rough figure to have, although I'm sure near impossible to get, as then we would know a ceiling limit to design to. A gutter's flow rate depends a lot on slope, length and preferably not having internal gutter clips. The link below will assist but note that I would never recommend having a minimal 1:500 gutter slope on which the figures are based. https://www.acegutters.com.au/technical ... -flow-rate 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Hi, Apologies - I know there is plenty out there on this but struggling to put together the puzzle. We're planning our garage/external laundry to master bedroom and… 0 11109 Once you know the basics, the rest is easy. Read my post in the thread linked below. viewtopic.php?p=1919271#p1919271 2 19515 18 90471 |