Another ASHP plumbing schematic!

[PeterW]

  On 08/06/2021 at 07:11, JulianB said:

All the pipework is within the thermal envelope of the building if it helps...would be it a show stopper if half of the pipework was uninsulated?

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BRegs/WRAS requirement to insulate all visible pipework for the UVC. 
 

If you use something like 22x9 Armaflex it will go under those clips or just get some spacers for the clips. I have to say since working with @Nickfromwales I now use Munsen rings everywhere with copper and not plastic clips ..!! They only get used for Hep2O..!

 

  On 08/06/2021 at 07:11, JulianB said:

I've stepped the hot water manifold outwards above it so that I can slot the cold water pipes underneath

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Just zoomed in and seen that ..!

 

Where does the tundish run off to ..?? How long and what diameter etc ..??

 

Also worth getting a coat of paint onto that OSB - acrylic eggshell or something just to make it brighter although as it’s under stairs just check your BCO doesn’t want it boarded out before you commit the pipework. 
 

 

[Nickfromwales]

  On 08/06/2021 at 06:19, JulianB said:

and more importantly can be taken apart again if I've missed something!). Comments welcome!

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Get rid of the T before the tundish. If you’ve no more height to play with, T the 22mm D2 as low as you can, do a second riser and fit a second tundish. The swirl of water hitting that T as is, will see water going everywhere except into the tundish. A strange phenomenon but ask me how I know lol. 
 

Nice work btw. I’ll look again later to see if I can add anything more.
Get some Munson rings on, and then you can lose the battens and insulate freely.?

[Nickfromwales]

  On 08/06/2021 at 07:17, PeterW said:

since working with @Nickfromwales 

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“Luke……I am your farter” ?

[JulianB]

  On 08/06/2021 at 07:26, Nickfromwales said:

Get rid of the T before the tundish. If you’ve no more height to play with, T the 22mm D2 as low as you can, do a second riser and fit a second tundish. The swirl of water hitting that T as is, will see water going everywhere except into the tundish. A strange phenomenon but ask me how I know lol. 
 

Nice work btw. I’ll look again later to see if I can add anything more.
Get some Munson rings on, and then you can lose the battens and insulate freely.?

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Thanks! I had to squeeze it in up there due to being tight on the 300mm pipe on D2...Thought about another Tundish...will look into it again

 

  On 08/06/2021 at 07:17, PeterW said:

BRegs/WRAS requirement to insulate all visible pipework for the UVC. 
 

If you use something like 22x9 Armaflex it will go under those clips or just get some spacers for the clips. I have to say since working with @Nickfromwales I now use Munsen rings everywhere with copper and not plastic clips ..!! They only get used for Hep2O..!

 

Just zoomed in and seen that ..!

 

Where does the tundish run off to ..?? How long and what diameter etc ..??

 

Also worth getting a coat of paint onto that OSB - acrylic eggshell or something just to make it brighter although as it’s under stairs just check your BCO doesn’t want it boarded out before you commit the pipework. 
 

 

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Interesting that it's BREGs requirement...does that include the Central heating side or just downstream of 3 way valve to UVC (& back)? Tundish currently runs out near the flow and return of the HP, and will terminate above ground in some form of cage (adjacent to the ASHP). The tundish is 22 -> 28mm, and I just managed to get away with the 300mm straight pipe for D2 before going off to the right. 

[JulianB]

The D2 run to the right is 2 metres to the termination point by the way!

[Triassic]

wondering how the installations going and if you modified your design in the light of doing the install?

 

I only ask as I'm about to buy all the kit this week!

[JulianB]

  On 03/08/2021 at 11:57, Triassic said:

wondering how the installations going and if you modified your design in the light of doing the install?

 

I only ask as I'm about to buy all the kit this week!

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Hi Triassic!

 

Touch wood so far so good...since my last update, I have also fitted the armaflex pipe lagging in 9mm in line with Peter's advice, and tested out the two relief valves to ensure that I didn't get any splash back out of the tundish (running 22 >28mm Tundish which is a fair size). I've wired it all in and gone through the set up / commissioning procedure which was fairly painless; the one area which wasn't as per the manual was the 3 way valve wiring; I found that it needs both white and grey wires connected to a single terminal on the ASHP motherboard. I've also run a contactor to take the no voltage short circuit from the high limit stat (UVC) to the ASHP which wasn't explained either. The only thing I'm not terribly keen on is the fact that the 2 way motorised valve which is down stream of the 3 way valve on the Hot water side and in line with the high limit stat is always energised, however was told this is the done thing!

 

 

[crispy_wafer]

@JulianB Without taking the thread off topic too much, how did you find the pressfit tool, did it do everything you wanted, any shortcomings?  Did you use copper and press for the whole project or did you revert to pex for the runs between endpoints?

[JulianB]

  On 04/08/2021 at 06:45, crispy_wafer said:

@JulianB Without taking the thread off topic too much, how did you find the pressfit tool, did it do everything you wanted, any shortcomings?  Did you use copper and press for the whole project or did you revert to pex for the runs between endpoints?

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The pressfit tool was a godsend! I did quite a bit of hunting online to find one at a reasonable price (~£400 with 3 jaws and deburring tool), and it definitely paid for itself in piece of mind, speed and ease of use. I marked every single fitting to ensure that the pipe was inserted to the correct depth prior to pressing, and that was really it. The only word of caution is that you need to be pretty much perpendicular / square to the pipe run when pressing the fitting; I attempted one at a bit of an angle and the back of the fitting didn't quite press to the same shape so I ended up replacing it. The other thing that can happen if you're not quite square is that it rotates the fitting as it clamps which could be troublesome if it's a 45 or 90 bend...this also only happened to me once, but I also made it a point to press bends before any tee's or straight connectors to give me the freedom to make any adjustments downstream! Lastly...the jaws I was using could happily wrap around the fitting with the pipe clipped into place on the wall, however some of my pipe runs which ran close to one another were a little too tight for it... I found that I had to plan which sections I pressed prior to clipping in place, and which sections I pressed in place when dealing with these close proximity runs...it just takes a little bit of thinking to ensure you've got your pressing sequence right if in a tight space like in my case... Either way, big thumbs up from my side

[Chanmenie]

Which pressfit did you buy ?
the ones I have found are over £1000

[JulianB]

  On 04/08/2021 at 18:47, Chanmenie said:

Which pressfit did you buy ?
the ones I have found are over £1000

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In the end I went for the Novopress EFP2 - one of the older models...slightly bulkier but I found it great for my application (which was quite tight!). I had also purchased a Novopress Eco 301 which came in for a bit more money but ended up returning it as saw no advantage over the older EFP2. As for the jaws...the difficulty I found was precisely knowing whether the jaws will fit a particular model... I couldn't really find much online, and in the end I went for a gamble and bought a Geberit 3 jaw kit (15, 22, 28mm M profile) which came good! I did have to buy and return a few jaws along the way...but it saved me quite a bit of money! 

[crispy_wafer]

@JulianB that helps a lot.  I see the tools are pricey, even 2nd hand, but there must be a good chance of getting most of the investment back when finished with it.  I take a bit of confidence in seeing that jobbing plumbers are now starting to adopt the method.

[JulianB]

  On 05/08/2021 at 07:48, crispy_wafer said:

@JulianB that helps a lot.  I see the tools are pricey, even 2nd hand, but there must be a good chance of getting most of the investment back when finished with it.  I take a bit of confidence in seeing that jobbing plumbers are now starting to adopt the method.

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Agreed...initially I couldn't really find anything under £500, but I kept a few alerts on and eventually the right one popped up (buying the jaws separately I found helped too). The older Novopress generally goes for 50-150 for just the pressing gun - the first one I had sourced from eBay was a low starting bid and no interest whatsoever, so I ended up getting it for an absolute bargain...but that sadly got stolen when we were burgled and the next one I watched went for over 3 times the original price I had paid!

 

Now that I keep my eyes out for the press fittings, I do notice them quite a bit when I pop into places - a friend mentioned that down in London, most plumbers have switched over to them rather than solder given the advantages, however I can understand that it will take some time to trickle through to all plumbers seeing as buying new they're in the thousands! My original plan was to sell on my kit once I've finished the build, however it was such a joy to work with, I've decided that it deserves to stay in my collection!

[Triassic]

At that price I’ll be sticking with old fashioned soldering!