A question on shower performance

[fezster]

I wanted to get some expert opinions to either confirm or correct my understanding on the performance of my thermostatic showers. I have 3 showers in my property, running off of a Megaflo unvented cylinder. The distance from the cylinder is approximately 9, 16 and 20m respectively (very rough guesstimates).

It's quite obvious that the first of these showers gives the best performance, with the other 2 roughly equivalent. All are decent, but none are equivalent to "so much pressure it's like needles in your back". The hot and cold water feeds to the showers consist of 22mm runs (and I'm assuming reduced to 15mm very close to the shower inlet - unless they have 22mm inlets).

I wanted to confirm if the best way of improving the performance of the shower would be to upgrade the main hot/cold feeds running through the house to 28mm (leave the tees in 22mm)? That is my understanding, I wanted to confirm it. It's not something I'd do immediately, but if the opportunity presented itself in future (carpets replaced, floorboards up), I'd like to know this is the right thing to do.

My other question is that both the hot and cold supplies are balanced, and restricted to 3 bar. This seems to be normal for most unvented cylinders. Why 3 bar though? And do any unvented's allow a higher pressure, and if so, would this also improve shower performance?

 

[fezster]

46 views, no responses

Anyone that can offer any advice? Thanks.

 

[Dean744PiN5]

unvented's are restricted to 3bar by regulations and for safety reasons, that should still give you a very powerful shower depending on type of shower head, drench or rain type heads by their very nature give poor pressure but good flow due to their large surface area, if this is what you have changing them for attachments with with a more concentrated spray will give you that "taking the skin of performance"

Increasing pipe size will have a negligible impact on your pressure but will increase flow to heads that require a higher flow rate but as your supplies are already 22mm i doubt this would be necessary .

Have you tried cleaning out any filters in the valves?

bad for power shower type spray

good for power shower type spray

this is assuming that you actually have 3bar and a high dynamic flow rate coming into the property.

 

[Dan Robinson]

high dynamic flow rate

Don't you start .


BTW there is are a couple of manufacturer's that allow more than 3 bar .

 

[Dean744PiN5]

fook did i actually write that, forgive me i have spent all evening trying to fix a crapple 6s my brain is frazzled so much i'm writing like Tony

 

[Agile]

Virtually all showers supplied at 3 bar will operate well with a 15 mm pipe size per shower.

Larger sizes will normally just waste water and take longer for the hot to reach the shower.

It may be more useful to fit a pressure gauge and see what the pressure at the cylinder output actually is.

Has it really been serviced every year as recommended?

Tony

 

[fezster]

Thanks guys - I didn't really consider the smaller shower head, but makes perfect sense.

The performance of all of the showers is more than acceptable. However, there is a difference between the closest and furthest, and I wanted to understand the reasons for this (and possible future solutions). And yes, Tony, the unvented and boiler are serviced annually . The performance has been the same since the start, it hasn't gotten any worse over time. Interestingly, the shower head which is closest to the cylinder is slightly larger than the other 2, yet still gives the most powerful output.

Just to give an idea, with all 3 showers running, the performance is still very good (though reduced, of course, compared to a single shower running).

 

[fezster]

Revisiting this thread, as I'm still not clear on an answer. Incoming mains is 32mm MDPE, over 5 bar, and over 60 litres/minute.

The hot and cold supplies are balanced using a 3 bar pressure reducing valve. Is there any advantage to having two pressure reducing valves - one for hot and one for cold. The idea being that 3 bar dedicated to hot and to cold will provide better performance than 3 bar shared across hot and cold, when multiple outlets are in use?

There is a definite performance drop when a second shower is activated, and I want to understand if there is a solution. Seems as if having such a great incoming supply is almost negated by the cylinder only working at 3 bar. In which case, is the solution to get an unvented that works at higher than 3 bar?

EDIT - to add, the incoming mains is 32mm MDPE, but reduces to 22mm after the stop cock - reason being that it goes into a Tapworks AD11 water softener. This has a high flow valve, but not sure if it may be causing a restriction.

 

[muggles]

Is your water softener connected with flexible hoses? If so, these will be causing a huge restriction

 

[fezster]

Really? Could you explain why, please?

The other thing I've found is that Hep2o has a smaller internal diameter than copper. But I couldnt find data on how much smaller? Much of the hot and cold feeds running through the house are in 22mm Hep2o. How much of a reduction in flow rate would these give compared to the equivalent in copper?

 

[muggles]

The internal bore of the hoses connecting water could be as little as 12mm. Get it repiped with copper and you should notice a difference

 

[fezster]

Get regius repiped with copper and you should notice a difference

Was that a mistype? Or something I didn't understand - did you mean, get it repiped in copper.

Correction to my earlier post, I have polyplumb, not hep2o (in case it matters).

 

[muggles]

Sorry, predictive text typo, now corrected

 

[fezster]

Thanks. Not something I can do at the moment, but at least I know what to try if/when the opportunity arises.

 

[flameport]

If the water softener is suspected to be the problem, turn off the two valves going to it and open the bypass valve. Now see if the shower is any different.