What is MAINS pressure? and is RAIN shower anygood

gabbysnana, Oct 29, 12:40am
No and yes so yes.
zirconium, Oct 29, 12:47am
I did a bit of reading around this when we built rurally in 2007. What i found out:

- Modern pumps supply at about 10 bar pressure. (Mains pressure is about 3.5 bar. Ours is throttled into the house, but we can just about waterblast with the hose!)

All pumps like to push better than pull, so it is better if the pump is below the water tank and the house, so it has to push water uphil a bit.

If you are going to get a halfway decent shower, check out getting a pump. Our gudfos has kept going without a break for 8 years now. We just have an easy-clean pre filter on the tank to stop most of the rubbish going in.
zirconium, Oct 29, 12:49am
sorry, pump make is something like grundfoss. Bad spelling.
medcare, Oct 29, 1:00am
Mains pressure in town can vary from 50 to 90PSI, the pressure at our office sink tap is 92PSI, which is very much on the high side.

Gravity fed pressure is directed related to the height of the tank, 1 metre of tank height (above the sink tap level) will give you 1.5 PSI of gravity

So if the base of your water tank is 10 metres above the sink tap, then you will get 10 metres x 1.5 = 15 PSI of pressure at your tap. By the same logic if the tank is 2metres high, then when full to the top the pressure at the tap will actually be 12 x 1.5 = 18PSI
medcare, Oct 29, 1:08am
So the perception of low pressure could simply be there is insufficient tank height, so if you raise the tank then your pressure will increase by 1.5PSI per metre raised.

Another cause can be using high pressure taps and shower mixers on gravity fed system, they will work on low pressure but they simply don't work very well.

The other cause of apparent low pressure can be too thinner pipes from the gravity tank to the taps, if you only have 4-5 metres of tank height (6-7.5 PSI of pressure) and you are feeding the house from say a 15mm pipe then when 1 or more taps are on you can get a very poor flow, which makes it look a lot worse then it could be.

if instead you feed the house with say a 32mm pipe then the flow will be greater (but not the pressure) and in many cases this is fine.

In the PERFECT gravity fed world you would actually run 2 x 32mm pipes, one would pretty much feed just the hot water cylinder and another to feed the house taps, that way when one person is in the shower and another turns a tap on then no one gets a frozen shower or worse scolded.
medcare, Oct 29, 1:13am
The shower you linked to will certainly not work on low pressure.

As for the pump, this will only boost the hot water, not the cold water, so this also won't work well.

You may be better to add a booster pump at the entry of the tank water to the house, but before doing so you must ensure all your internal pipe work, taps, mixers and especially the hot water cylinder will not be damaged by the higher pressure water.
skin1235, Oct 29, 1:29am
so why not get two pumps (like the one linked to), put one on the cold system after the hot water cylinder, and one on the hot system after the cylinder, the systems are non vented after those points and the taps you have will suffice
$200 and the jobs done , no you don't actually need a plumber to do it, ( you do need to be able to identify both system and were to put the pumps though, and you will need at least one mac union per pump, preferably two) although technically you may need a sparky to put a hot plug in the appropriate spot

not sure if those pumps come fitted with a pressure switch or the non return valve - they need both to be able to work properly, some sellers like to sell you them as extras

$2000+ for a mains cylinder and the plumber is likely to be on top of that
even if you obeyed all the new laws andgot a sparky in to fit a double hot plug it wouldn't cost too much - meds would be able to tell rough prices to extend a closeby circuit
jacqui248, Oct 29, 2:28am
hmm ok thanks . interesting
lythande1, Oct 29, 1:05pm
As you do not have mains (Or really it is HIGH) pressure, you cannot buy anything that says mains pressure.
Yes a booster pump does increase the force of your shower.

However it does not mean you can then buy a mixer suitable for mains, you still must look at low pressure mixers only.
Shower, bathroom mixers, kitchen mixers, all must be low pressure only.
zirconium, Oct 29, 3:58pm
The Tempercon booster pumps get quite good reviews, people seem to think they do quite well what they are supposed to.

Google "reviews, tempercon booster pump" :)
trad, Oct 29, 4:12pm
I would contact a water pump supplier/manufacturer and ask for advice on a system suitable for you. IOW, further your schooling on various systems or set-ups that will do your job. Here is a link to start with : http://www.purewaterservices.co.nz/rural/water-pumps/new-water-pumps
maddie44, Oct 29, 6:33pm
One other thing with a rain shower, how much water does it use, ltre/pm?
Will your water supply cope with that usage?
beanies, Oct 29, 9:40pm
We have something similar to this in our bathroom but hardly use the rain shower (dumper).
The rain shower is great on hot days when you want a cold shower (it just feels sooooooo good) but hard to use when you want a shower without wetting your hair or for that few minute wait before rinsing our your conditioner. They do create more steam than a normal shower and because of the height you cant install a shower dome or anything so you need a well ventilated bathroom. In winter, even running the bathroom heater and an exhaust fan we have water running down the walls when the dumper is used yet get nothing like that with the normal shower head. I think part of it is that you seem have the water that little bit hotter when using it and the height of the dumper being slightly above the shower screen.
Personally if we were doing up a bathroom and had to do anything special to be able to put one in I wouldn't bother.
skin1235, Oct 29, 11:44pm
and yet these addons are requried at greater cost to make it work as intended
"1. You need to fit Tempercon Check Valve at pump inlet for 100% performance.
2. You need to fit Tempercon Flow Switch at pump outlet for automatic operation.
3. You need to buy Tempercon special hot water type Check Valve $30. If you do not buy & fit correctly, booster pump is not covered by warranty."

there something offputting about buying a pump to do a job and then have to buy extra bits to make it work - why don't they sell them as a complete unit ready to go
jane310567, Oct 30, 2:35am
we have a rain head in our shower - used it once! No-one likes it - we all like the rail type as you can shower without wetting your head!
kmole, Nov 1, 9:36pm
I asked the same questions on here a few years back. Had terrible shower pressure. Ended up installing a pump I think from my Hwc to my hw taps. I also have a pump out at my tank that keeps cold pressure up. Now we churn through hot water, but it is soo worth it.
I also installed solar heating at the same time, so that meant a new Hwc but that would be worth thinking about if you will use more hot water. combined with a wetback I haven't heated my hot water by electricity in about 5 years. Would love a bigger cylinder than my current 360 litre I have now.
skin1235, Aug 11, 4:47pm
I ended up being heartily p***ed off with the hot water usage here, low pressure system but even that couldn't cope with the kids etc
one day Millens had a sale on and I picked up a 5lt min califont that runs off a standard gas bottle, took a feed off the mains cold coming in and fed it through a tap into the califont
I get hot water at my desired temp at anytime, endless basically, get about 10 weeks out of a $36 bottle of gas, used for showers and handbasin in the bathroom
honestly cannot fault it although we are lucky - we have a 4 mt stud so ventilation and gas exhaust is not a problem, would need to be external vented if on a standard 2.8 mt stud home, but they do include a wall external vent with them anyway, just cut the hole and fit the fitting to the top of the califont