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Today's install.

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virgil said:
Vern, out of interest why have you lagged the D2 pipe on your nursing home install?
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Welcome Virgil......more pipe protection than anything, it's a working laundry room and small at that, lots of laundry baskets in an out
 
peteheat said:
A question more than a comment;

Is the pressure vessel upside down?

Reason I ask is all solar diagrams say the Schrader facing down, old school says facing up and the big vessels on legs it's up.

Who is right?
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Kind of confusing having the vessel instructions telling you schrader up and the fitting instructions for the kit telling you schrader down.

Depends on your likes, Schrader down leads to a much higher failure rate in my experience.
 
Question to whn1: why 22mm HW pipe? 15mm gets the hot water much quicker to the taps. And loosing a few hundred millibar at 3bar standing pressure will not kill you.

But otherwise its just looking bonny.
 
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Best thing about UV is the can size pipes properly. 22 for bath, 15 for showers and 10 for basins. Can save a lot in wasted heat and water.
 
Whn1 said:
22mm feeds straight to the bath taps to give optimum flow rate.
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At 37l/min HW you are still below 2m/s. That gives you around 56l/min mixed water. At an appliance that is designed not to give off more than 36l/min HW at 1bar. So you can loose 2+ bar in your pipes. Which gives you an equivalent pipe length of over 100m. If you would use that pipe length then a quarter of you 120l cylinder gets used just to fill the pipes.
From a 15mm pipe you still get 20l/min at an equivalent of 40m.
(Hot water, not mixed water)
 
DirksPlumbing said:
At 37l/min HW you are still below 2m/s. That gives you around 56l/min mixed water. At an appliance that is designed not to give off more than 36l/min HW at 1bar. So you can loose 2+ bar in your pipes. Which gives you an equivalent pipe length of over 100m. If you would use that pipe length then a quarter of you 120l cylinder gets used just to fill the pipes.
From a 15mm pipe you still get 20l/min at an equivalent of 40m.
(Hot water, not mixed water)
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Interesting point
 
If you avoid stopcocks in the HW pipe you could even go to 5m/s which provides you with 40l/min. draw offs apparently share what is there. At 20l/min you can have 3 showers going at the same time or 1 shower and one filling the bath at the same speed as with an 35kW combi on its own. You just need to watch your hydraulics a bit for not preferring the bath to much as it could rob the other appliances.
 
DirksPlumbing said:
If you avoid stopcocks in the HW pipe you could even go to 5m/s which provides you with 40l/min. draw offs apparently share what is there. At 20l/min you can have 3 showers going at the same time or 1 shower and one filling the bath at the same speed as with an 35kW combi on its own. You just need to watch your hydraulics a bit for not preferring the bath to much as it could rob the other appliances.
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what do you mean "watch your hydraulics" , like your posts
 
With hydraulics I meant the way the pipe runs. Like having a long run to the bath and the shower mixer (hot) close to the bath of the branch could lead to an unpleasant pressure drop if someone starts filling the bath whilst an other one uses the shower.

Or the less likely event that your mains only supplies a low pressure and/ or low flow rate.
 
If the pipe has not been sized correctly the volume of water traveling to one outlet may be adversely affected if another outlet, on the same run, is opened at the same time.
 
I'm still sure the way I've always done it is correct, so in this case 22 mm straight to the bath first teeing of for sink then basin and shower in the bathroom then reduced after the bath to feed the shower and basin in the on suite in the next room.
 
Should have added as well, without carefully deburring the pipe you would not get a very happy customer if you design the pipework for 5m/s flow speed.


@whn1: not a problem.


@SafeGasInstall: Not necessarily. But it could indeed be of advance to have individual supplies for every bath room. May well save you the effort of a secondary return. Just depending on the situation.

Quite unlikely someone would use the shower at the same time as another one runs the bath in the same bathroom if there is more than one bathroom for example. Unless it is a huge family squeezed in a tiny bungalow.

You do not need to size pipes for the one in a million case that all appliances in the household are getting used simultaneously.
 
Whn1 said:
I'm still sure the way I've always done it is correct, so in this case 22 mm straight to the bath first teeing of for sink then basin and shower in the bathroom then reduced after the bath to feed the shower and basin in the on suite in the next room.
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Not saying that you are wrong. Just saying it is worth to consider if you can safe the material and the customers time and energy just by such a simple trick as downsizing the pipe.
 
SafeGasInstall said:
Now I am more confused ...... I better go back watching tv
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Hahah, it's been a long day, I'm trying to watch football and now because of dirk I've I've got flow rates and litres per minute running through my head. Thanks dirk 😉
 
Majority of basin taps size is 1/2inch
And bath taps 3/4inch
So 22 pipe should always imho be going to a bath yes 15mm will have pressure but not flow on a correct installation
 
Gray's back in da house!

Speaking of which, how's it going?

Was in Omagh DVTA t'other week, head and choulders in their biomass.
 
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