Browse Forums Eco Living Re: Plumbing consultant / Hydraulic engineer recommendation 3May 27, 2020 12:15 pm supa007 I've been reading SaveH2O's very informative posts to learn about things, but there's just too much to take in... I provide answers by way of explanation with correct technical terms so that people who want information will understand and be able to reference correct terms for further clarification if needed. It is then up to individuals to decide as to whether they want to substantially short cut and benefit from the research undertaken by the person who is trying to help them and others. supa007 Our builder whom seem to share our enthusiasm for a quality build has been disappointed by run of the mill plumbers they've used so far, therefore is keen to involve a plumbing consultant / hydraulic engineer to ensure that everything is done to best practices. Any recommendations for such a person / firm? Unfortunately, I cannot recommend anyone. You need a hydraulic engineer who is also a rainwater harvesting expert but as you have probably seen in the hydraulic assessments sometimes posted on Homeone, they often lack real life understanding but the usual seemingly endemic mistakes are easily identified. You need to garner knowledge and advise whatever 'expert' you find. An irrigation specialist is often the best choice. Are you on the water grid? I noticed in the first posted image it states: "Notes: - all downpipes and gutters to be in accordance with: A) AS/NZS 3500.3 B) Section 5 of AS/NZS 3500.5 -all downpipes indicated are 90mm - calculations and downpipe layout to indicate compliance with NCC 2016 Part 3.5.2 Gutters and Downpipes. - figures calculated using a 5 minute duration rainfall intensity of 340mm/h (Bundaburg). - figures calculated using a Type B gutter (large rectangular gutter) with a cross sectional area of 7.900 sq mm." Observations: AS/NZS 3500.3 is a Deemed To Satisfy (DTS) solution referenced in the Plumbing Code of Australia (PCA) which is Part 3 of the National Construction Code (NCC) and also in NCC Part 2 3.5.3 The NCC Part 2 is the primary document and thus has hierarchy over the Australian Standards. It has to be noted that NCC Part 2 3.5.3 has calculations that are lesser than those in AS/NZS 3500.3, therefore if the NCC Part 2 is referenced in accordance, then they will often not meet the Australian Standards found in AS/NZS 3500.3 The statement that all downpipes and gutters must be in accordance with AS/NZS 3500.3 is misleading unless the provisions found in the NCC Part 2 3.5.3 are deleted from the contract. AS/NZS 3500.5 compiled other Standards and was delisted a couple of years ago. NCC 2019 should be referenced, not 2016. The 1:20 Average Recurrence Interval (ARI) used to determine eaves gutter compliance is not 340mm/r (an average of 5.666 mm per minute over a 5 minute rain intensity duration). It appears that the 1:100 ARI which is used to calculate box gutter compliance has been mistakenly referenced. For Bundaburg, if the Intensity Frequency Duration (IFD) or the AS/NZS 3500.3 grid referenced ARI is used, then it is 240 mm/h (a minimum average of 4 mm per minute over a 5 minute rain intensity duration. I cannot comment on the gutter or downpipe size as I don't know the roof areas drained to each downpipe which are distinct from the roof areas indicated as they don't drain to single downpipes. It should also be noted the following average minimum total flows per minute off the roof over a 5 minute duration. 340 mm/h 1:20 ARI: 1,821 lpm. 240 mm/h 1:20 ARI: 1,285 lpm. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ I think that you need to accept that your 1:20 ARI will generate a minimum average of 1285 mm per minute. You also need a safety margin. A nominal 150mm DWV pvc pipe has an inside diameter of 151.6 mm which equates to a volume of 18.05 litres per metre. A velocity of 1.5 metres per second gives a flow rate of 1,625 litres per minute (provided there is sufficient hydraulic head). A 225mm DWV pipe will easily accept the flow from two converging 100mm (104mm internal diameter) pvc DWV pipes flowing with similar flow rates. Use a junction, not a tee. To considerably improve the wet system, have a DIY sediment trap fitted to a non turbulent length of pipe to capture the bed load. Fitting a low restriction inlet to the tank has numerous advantages but water must first pass through mosquito proof mesh and your local regulations most probably mandate fitting a mosquito proof leaf diverter and a first flush diverter to the wet system. DO NOT fit a first flush system at the tank's vertical riser like just about all plumbers do! In order to collect the first flush, first flush diverters must be fitted to the downpipes. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ The DIY sediment trap and low restriction inlet resulted from our Supadiverta research and development program. You should also consider collectively plumbing first flush pipes to a single first flush tank that can be used for outdoor use. This will decrease yield loss and has aesthetic benefits. The one below isn't the best design but it shows a necessary levelling vent. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Because of the large roof area and high annual rainfall, you will need big tanks. Seriously consider having two large tanks to use as a settling system whereby water is diverted to tank 1 and decanted water is then supplied to tank two. The thread that I have linked below uses a floating filter inlet hose to transfer water from below the water surface in the settling tank to the tank that supplies the pump. Look for the photos. viewtopic.php?f=35&t=97686 The inflow will be huge during heavy rain and there will be a big demand on the overflow should the tank(s) fill. Having an overflow pipe fitted to the side of the settling tank reduces storage capacity unless you plumb the internal pipe upwards. A vertical outlet flows a lot faster than a horizontal outlet plus you can bellmouth the intake for greater weir flow. Doubling the intake diameter increases the weir perimeter x4. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ If you have a submersible pump that draws water from the bottom of the pump, have it raised off the tank's floor to prevent it vacuuming the floor (like most do). Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ 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: Plumbing consultant / Hydraulic engineer recommendation 4May 27, 2020 5:12 pm Thank you for such comprehensive reply SaveH2O. I appreciate experts like yourself taking the time to contribute to forum members' desire for information and answers. I have much, much more to learn... Yes I'm on the usual suburban water grid. I did pick up that 1:100 ARI was used for calculations, but thought it's better to have some margin of safety built-in and didn't question it. Also, the document was prepared early 2019, prior to NCC 2019 coming in around May I recall. Will have the drafter update the documentation, thank you for pointing it out. Re: Plumbing consultant / Hydraulic engineer recommendation 5May 27, 2020 5:42 pm A labour of love, much better than rushing such a unique project. Will you be starting a build thread? I will follow if you are, I love this type of build. Are you in wind zone B or C? 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: Plumbing consultant / Hydraulic engineer recommendation 6May 27, 2020 8:44 pm Definitely a labour of love. Didn't realize that the decision to go unconventional would bring such challenges... We'll hopefully be starting soon, pending engineering, almost 3 yrs since the planning began... Essentially it will be an ICF (insulated concrete form) structure. One of the reasons why we chose ICF construction is that we're in a cyclonic area. Images of lightweight construction torn to pieces by cyclonic winds just worries me for our "forever house". Especially with climate change bringing extreme weather events more frequently. However, rather than the more conventional polystyrene formwork, we've decided on using Durisol (decelluarized wood chip / cement mix) formed into Besser-like blocks. Because ICFs are not common, and Durisol system even less so, it's been a challenge just to find a builder willing to take on the project. On top of this, we've even had issues with a local certifier not willing to issue building approval because there's no CodeMark on the Durisol product, as well as not accepting the Deem to Satisfy solution... Anyway, to answer Alex79's questions, we will have imported European (Internorm) triple glazed windows (Uw-0.76), under slab insulation, ERV system, heat pump HWS, battery ready solar system (waiting for Fronius Gen24+ hybrid inverters). You have to choose your energy assessor carefully. Some are better at manipulating the program to better reflect actual construction (especially in my situation where our product choice is not found in the drop down box). Will definitely try to start a building thread. However, it may be a very slow one... Re: Plumbing consultant / Hydraulic engineer recommendation 7Jan 18, 2021 9:56 pm Good luck supa007 with the build and definitely will be interested to see your build updates. I too am researching a high performance build and it is very challenging. I was wondering did you sort out your hot and cold water plumbing distribution? Did you go with a manifold distribution or ring main? Re: Plumbing consultant / Hydraulic engineer recommendation 8Jan 19, 2021 9:45 am For cold water, just normal branch distribution. For hot, I decided to go down ring main path as it seems more cost effective. I will however put in a water recirculator pump and have it under smart control (on demand as well as pre-set times) so it doesn’t act as a radiator all day long, all year round. 3 6668 The engineering is the engineering. It's irrelevant how much material you have. Unless it fits the requirements of your design the engineer can't "make"it work. You might… 7 9875 just ask a carpenter/ builder, if they are unsure they will get the engineer to advise. 1 1563 |