Trials and Tribulations of Eco installs.

[Marcus]

In a way it's panned out well as you got a pucker install in the end (although with about 10years worth of stress and aggravation).

I was wondering though:- there are two (well, maybe more) types of plastic pipe system- push fit where the outer diammeter is the same as copper, but I.d. is much less (especially with the inserts), but there's another system that's like the barrier pipe used in ufh, but it's diammeter is bigger such that the internal bore is equivalent to the standard copper, but needs adapters to join the standard plumbing because the O.D. is non-standard.

My installers used the latter for the long runs, I was wondering if your new install was the same?

[NoraBatty]

Sadly no, its all JG speedfit with the speedfit inserts and speedfit fittings.
Their 28mm pipe has an internal diameter of 22mm, and the inserts restrict the opening down to 18mm on a 28mm pipe.







This will be making a massive difference to flow rates and the inserts will also cause the flow to get turbulent.

The system works dont get me wrong, and is still more efficient than a gas boiler would be , but maximum efficiency has not been gotten out of the system, and it can be improved substantially.

[Marcus]

Pity.

But it gives you something to upgrade in your spare time

[AGT]

Slowly replace with MLCP would be an option if you wanted to consider upgrading the speedfit

[NoraBatty]

Yes, it does eventually.
As the system is now is what i was expecting the standard to be to be honest.
I know a government scheme is not going to be dishing out 5* services with bells and whistles, but you do expect a decent or at least competent level of system to be installed.

The works are almost finished, and i am much happier with the quality of the install now.
The company have kept their word and rectified what needed to be done, even rectifying additional bits they found that were not okay in the process. They didnt have much choice given the MCS certification and their own certification bodies hold them to a minimum standard, but it should be installed adequately in the first place, and not have to be remedied.

Once things have been completed and signed off we can start to actually make the house we moved into a home. Not a jobsite.

[NoraBatty]

Slowly replace with MLCP would be an option if you wanted to consider upgrading the speedfit

It is certainly worth a thought for the primary pipe run under the floor, but the fittings still have an insert that will reduce the flow.
Much less ID will be lost in comparison to speedfit for sure, and obviously this will only occur in 2 places where the inserts are, start and end given such a long run is possible.

Do you, or anyone have any figures on if 6 butt joins in copper with no reduction in ID is worse for flow than 2 fittings either end of a run in mlcp if the same bore is used?!

I suspect this may be a yes and mlcp will be better.
If its literally negligible, i may as well stick with copper for the run if i can get it under there in 3m sections, because i already have quite a bit , plus press fittings, to make a dent in the changes.

[AGT]

MLCP is available in larger size coils to reduce the number of joins and in many more diameters than speedfi to size up to compensate for the internal diameter too.

Might be easier to feed a length of copper in through an air vent to get full lengths under the floor if possible

[Stinsy]

The critical part is from the HP to the first T after that 28mm Speedfit is fine.

[NoraBatty]

Hmm. The first tee, is currently a pipe run of approximately 17m away, entering in the floor void on one corner of the house, across to the opposite corner all in plastic, then up into the loft to the 3 port valve in copper, but with sharp pushfit elbows not swept pressfits.
But its a very handy bit of info to have Stinsy, thank you.

I had a good look for the pipe restriction numbers in mlcp fittings last night and drew a blank.
As you say AGT I could bump up to a 40mm mlcp pipe which would give an ID of 33mm, leaving 6 mil for the insert, which hopefully would then match or exceed 26mm, but until i have a look at a fitting i wont be able to know for sure how the insert acts.



There may be more joins in 3m copper, but at least the internal bore is consistently 26mm, and i already have at least 21metres of 28mm copper and a couple of bags of pressfits.
At least with the plastic out, i dont have to buy hdpe for making the veggie garden hoop houses!

The air vents are cast iron monkeys that are as deep as the wall unfortunately. It may be easier to drill at the sides of these than through the wall directly, but even if i did, that nonsense outside has to be rectified properly by re routing into the wall higher up. . The conservatory joists run in my favour, and there is clearly a hole for the soil pipe, hence why i think that the best option if i can.

[Stinsy]

Hmm. The first tee, is currently a pipe run of approximately 17m away, entering in the floor void on one corner of the house, across to the opposite corner all in plastic, then up into the loft to the 3 port valve in copper, but with sharp pushfit elbows not swept pressfits.
But its a very handy bit of info to have Stinsy, thank you.

I had a good look for the pipe restriction numbers in mlcp fittings last night and drew a blank.
As you say AGT I could bump up to a 40mm mlcp pipe which would give an ID of 33mm, leaving 6 mil for the insert, which hopefully would then match or exceed 26mm, but until i have a look at a fitting i wont be able to know for sure how the insert acts.



There may be more joins in 3m copper, but at least the internal bore is consistently 26mm, and i already have at least 21metres of 28mm copper and a couple of bags of pressfits.
At least with the plastic out, i dont have to buy hdpe for making the veggie garden hoop houses!

The air vents are cast iron monkeys that are as deep as the wall unfortunately. It may be easier to drill at the sides of these than through the wall directly, but even if i did, that nonsense outside has to be rectified properly by re routing into the wall higher up. . The conservatory joists run in my favour, and there is clearly a hole for the soil pipe, hence why i think that the best option if i can.

That really is a horrendous design! I've managed to read this whole thread without understanding that the HP is located so far from the start from the system! That run REALLY needs to be 40mm and very well-insulated indeed and have no fittings if possible. Have a look at "Urban Plumbers" on youtube. The guy has done some challenging HP installs, I remember one similar to yours where the flow/return from the HP was long and he did exactly that.

Many years ago I bought an ex-council semi to renovate. The dining room had a horrible damp problem to solve, the problem had clearly existed for decades. Plumber diagnosed the problem immediately, the 15mm copper dropped from the ceiling with a 90° at the bottom, ran along the skirting with another 90°in the corner, along that wall 90° at the corner, along the skirting to the rad with another 90° going up to the rad, then all the way back again for the return. The plumber said that no water would ever have flowed through that rad. We rejigged the pipes so that the same drop was reused but with a single elbow at the bottom to horizontal and another going up to the rad. We halved the number of 90°elbows, reduced the pipe length by way less than half and reused the same rad. Suddenly the room was warm and the damp problem disappeared.

I'm sure there are fancy calculations but the plumber told me: if the pipe run is longer than 15m then you need to go up a size and that every 90° elbow adds 1m. We originally had (something like) 15m of pipe and 8x elbows making 23m by his calculation. Swapping to (something like) 7m of pipe and 4x elbows made 11m by his calculation. I can attest that one worked and the other didn't!