Author Topic: Combined drains and discharge points (Read 6350 times)

newguy · « **on:** October 05, 2011, 04:13:00 PM »

Hi Guys, im struggling with Auckland council regulations and wanted to get you opinions on things. Firstly I would be interested to know how you guys combine the cold water expansion and tpr valve into one drain. Basically if my drain is not made of copper and is a minimum of 25mm the inspection fails! I have looked into the standards and cant seam to find a guideline in this regard, I know all about the drain sizing and the problem with copper is that it gets really expansive at 25mm. I can run the CWE separate with PVC but the TPR max 12 meters with no bends + it gets expansive.

Another issue we face is that with an uncontrolled heat source (there is a big debate whether solar is an uncontrolled heat source. Councils trying to prove yes and suppliers trying to prove no. And inspections are left to the inspectors discretion) the TPR can never discharge into the drain system and must run to a soaking hole outside. We then face the issue that as per NZBC the TPR drain cant be longer than 12 meters and for every bend it become a meter less. You cant win!

Has anyone had the same issues? How have you been able to streamline this problem to councils satisfaction? How do you guys usually combine the two, any pictures would much appreciated! thanks for your help in advance!

Linkback: https://www.plumbers.nz/ask-plumbers-trade/43/combined-drains-and-discharge-points/857/

integrated · « **Reply #1 on:** October 05, 2011, 08:32:23 PM »

Quote from: newguy on October 05, 2011, 04:13:00 PM

Hi Guys, im struggling with Auckland council regulations and wanted to get you opinions on things. Firstly I would be interested to know how you guys combine the cold water expansion and tpr valve into one drain. Basically if my drain is not made of copper and is a minimum of 25mm the inspection fails! I have looked into the standards and cant seam to find a guideline in this regard, I know all about the drain sizing and the problem with copper is that it gets really expansive at 25mm. I can run the CWE separate with PVC but the TPR max 12 meters with no bends + it gets expansive.

Another issue we face is that with an uncontrolled heat source (there is a big debate whether solar is an uncontrolled heat source. Councils trying to prove yes and suppliers trying to prove no. And inspections are left to the inspectors discretion) the TPR can never discharge into the drain system and must run to a soaking hole outside. We then face the issue that as per NZBC the TPR drain cant be longer than 12 meters and for every bend it become a meter less. You cant win!

Has anyone had the same issues? How have you been able to streamline this problem to councils satisfaction? How do you guys usually combine the two, any pictures would much appreciated! thanks for your help in advance!

technically solar IS an uncontrolled heat source - depending on system if power fails the ability to control system temps is null and void especially with evac tube

is your drain/relief longer than 12m?

you can combine the TPR & CWE but their are rules around that

alot of what you have said above is incorrect - your plumber should know better

if auckland council reqs 25mm drain pipe there is a reason for this

newguy · « **Reply #2 on:** October 05, 2011, 11:34:18 PM »

Hi integrated, I am a plumber. Yes in most cases the drain is longer than 12m, that's what makes it hard. What have I said that is incorrect? In regards to solar, if power fails then the pump is not working hence no hot water will be pumped back to the tank and stagnates in panel plus there has not been an official statement on this matter anywhere that I am aware of.

Please share the rules around "that" very interested.

integrated · « **Reply #3 on:** October 06, 2011, 06:39:06 PM »

Quote from: newguy on October 05, 2011, 11:34:18 PM

Hi integrated, I am a plumber. Yes in most cases the drain is longer than 12m, that's what makes it hard. What have I said that is incorrect? In regards to solar, if power fails then the pump is not working hence no hot water will be pumped back to the tank and stagnates in panel plus there has not been an official statement on this matter anywhere that I am aware of.

Please share the rules around "that" very interested.

registered licensed or certifying? - everything you need to know is outlined in g12

Quote from: newguy on October 05, 2011, 04:13:00 PM

Basically if my drain is not made of copper and is a minimum of 25mm the inspection fails! I have looked into the standards and cant seam to find a guideline in this regard.

drain size depends on safety valve sizing - material is mandated copper in g12

Quote from: newguy on October 05, 2011, 04:13:00 PM

I know all about the drain sizing and the problem with copper is that it gets really expansive at 25mm. I can run the CWE separate with PVC but the TPR max 12 meters with no bends + it gets expansive.

If you are required to have 25mm drain and you or your employer has not allowed for this then its tough titty basically

Quote from: newguy on October 05, 2011, 04:13:00 PM

Another issue we face is that with an uncontrolled heat source (there is a big debate whether solar is an uncontrolled heat source.

Solar IS an uncontrolled heat source - I say this as a Solar engineer - any REPUTABLE supplier will tell you the same

Quote from: newguy on October 05, 2011, 04:13:00 PM

TPR can never discharge into the drain system and must run to a soaking hole outside. We then face the issue that as per NZBC the TPR drain cant be longer than 12 meters and for every bend it become a meter less. You cant win!

the relief valve drain system in total can be greater than 12m

the tpr does not "have" to discharge to a soak hole

Quote from: newguy on October 05, 2011, 04:13:00 PM

Has anyone had the same issues? How have you been able to streamline this problem to councils satisfaction? How do you guys usually combine the two, any pictures would much appreciated! thanks for your help in advance!

as with all things there is more than one way to skin a cat - some lateral thought may be required, if the house is slab on ground with floor already down with only 20mm drain in place where a 25mm drain is legitimately required (not saying it is - I know too well how councils love to take the piss and exert authority) and you cannot run drain through internal framing then you may well be up the creek

integrated · « **Reply #4 on:** October 06, 2011, 06:44:25 PM »

Quote from: newguy on October 05, 2011, 11:34:18 PM

Hi integrated, I am a plumber.

Please share the rules around "that" very interested.

didnt mean to offend, a bit highly strung at the mo with everything going on in the industry - apologies, reading back can see how it may have come across!!

newguy · « **Reply #5 on:** October 06, 2011, 08:21:56 PM »

No Worries integrated, I feel the same way about whats going on. Why don't you have a look at the standard AS/NZS 3500.4:2003 Heated water services. There it clearly states how long your relief drain is allowed to be: Maximum relief drain length 9 meters Maximum amount of bends 3 and the table goes on up to a maximum of 12 meters with ZERO bends, cant argue with the code. Additionally the code also states that it is not always possible to combine the drains but must run them singular to a common discharge point unless they are exempt by 512.2 and 5.10.3 (multiple configuration) It also gives authorities the right to refuse interconnection (welcome to Auckland) .

In regards to Solar being an uncontrolled heat source WHERE is this written so I can refer to that? I don't believe such a document exists.

Ring up Auckland city council and ask for the head inspector of solar water heating, he signs off all solar heating installations. If he says you can discharge your TPR into ANY drain I will shout you a box of beers and lunch!

integrated · « **Reply #6 on:** October 06, 2011, 09:36:02 PM »

HA! Thats the spirit!!

Quote from: newguy on October 06, 2011, 08:21:56 PM

No Worries integrated, I feel the same way about whats going on. Why don't you have a look at the standard AS/NZS 3500.4:2003 Heated water services. There it clearly states how long your relief drain is allowed to be: Maximum relief drain length 9 meters Maximum amount of bends 3 and the table goes on up to a maximum of 12 meters with ZERO bends, cant argue with the code. Additionally the code also states that it is not always possible to combine the drains but must run them singular to a common discharge point unless they are exempt by 512.2 and 5.10.3 (multiple configuration) It also gives authorities the right to refuse interconnection (welcome to Auckland) .

Yes, but what is stopping you from discharging to a tun-dish and going again?

Quote from: newguy on October 06, 2011, 08:21:56 PM

In regards to Solar being an uncontrolled heat source WHERE is this written so I can refer to that? I don't believe such a document exists.

page 7, US25407 - under the heading "Safe Installation And Operation Of Solar Hot Water Systems"

Quote from: newguy on October 06, 2011, 08:21:56 PM

Ring up Auckland city council and ask for the head inspector of solar water heating, he signs off all solar heating installations. If he says you can discharge your TPR into ANY drain I will shout you a box of beers and lunch!

I never said it could discharge to any drain - what i am aware of however is that it is ONLY std upvc DWV pipe that you are not allowed to discharge to at temps OVER 55deg - e/w is ok as well as other specific hi-temp plastics

what I was getting at is that it only has to discharge in a safe & visible position which does not present a hazard or damage to other building elements, this doesnt HAVE to be nor can it ONLY be a soak hole - although I would consider that best trade practice

TS · « **Reply #7 on:** October 06, 2011, 10:33:28 PM »

I'm an inspector and I agree with Integrated comments.

Newguy, whatever your nominated means of compliance is you must stick to it. If that is G12/AS1 then your stuck with copper no more than 12 metres long.

Any other means is an "alternative solution" and can be okay, you just have to prove on paper that it'll work. One of the tests being if the TPR relieves water in excess of 95 degrees that the pipe doesn't melt. The building code is performance based meaning if it works it complies. It has to work in the worst case scenario however.

newguy · « **Reply #8 on:** October 06, 2011, 11:29:33 PM »

Thanks very much guys, real good and useful information. might still shout a box of beers aye ;o)

robbo · « **Reply #9 on:** October 15, 2011, 09:56:42 AM »

hi guys, my thoughts on solar being "uncontrolled" is that on my own system "evacuated 30 tube Apex System" when i go to Aussie on holidays i cover the panel with a white canvas sheet, that controlls it, also the sun only shines in the day if the system is balances: panel size to cylinder size, the water will never get above 80-90deg on the hottest day of the year so in that light it is controlled, thats how my system works,cheers

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Author Topic: Combined drains and discharge points (Read 6350 times)

newguy

Combined drains and discharge points

integrated

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integrated

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integrated

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TS

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