Low pressure mixer showers

malc_b

Hi,

Are there any other showers around like the Aqualisa Opto Thermo that is spec'ed to have a flow rate of 10 l/min at 0.1 bar? I have a very low cold water tank and a low roof, and I'd rather not have a pump. The current bath mixer shower gives an ok shower so I reckon this should work too. But surely there are other makers who do similar or is Aqualisa the only one?

TIA

keystone

What is the height of the top of the cold water tank to where the shower head will be installed?

Cheers

malc_b

Around 0.1bar or 1m. Ceiling is ~2.4m and cold water tank is in loft sitting on ceiling trusses. So call it 2.4-1.8+0.5 to water level. Marginal 1m since you need to assume the water level drops under shower load. Hence the reason I'm looking for a shower with the largest flow at 0.1 bar.

SuzieSue

I can't help with your question but the shower head also makes a big difference - our shower was almost unusable and we were thinking of getting a pump but I thought I would try this:

http://www.amazon.co.uk/Grohe-Euphoria-Mono-Hand-Showerhead/dp/B004X9QYRW

and it improved the flow so much that we didn't need to get a pump.

paulmapp8306

Check the Mira showers. They claim to work from as little as 0.1Bar.

http://www.mirashowers.co.uk/onlinecatalog/results.htm?sectionName=Mixer%20showers

southcoastrgi

malc_b wrote: »

Around 0.1bar or 1m. Ceiling is ~2.4m and cold water tank is in loft sitting on ceiling trusses. So call it 2.4-1.8+0.5 to water level. Marginal 1m since you need to assume the water level drops under shower load. Hence the reason I'm looking for a shower with the largest flow at 0.1 bar.

it's the bottom of the tank you measure from not the top of the water level

keystone

malc_b wrote: »

Around 0.1bar or 1m. Ceiling is ~2.4m and cold water tank is in loft sitting on ceiling trusses. So call it 2.4-1.8+0.5 to water level. Marginal 1m since you need to assume the water level drops under shower load. Hence the reason I'm looking for a shower with the largest flow at 0.1 bar.

If you don't provide the shower with a decent flow rate it won't produce one magically out of thin air. You don't have enough head. You need a pump IMO.

Cheers

keystone

SuzieSue wrote: »

and it improved the flow so much that we didn't need to get a pump.

The flow rate when measured at the end of the pipe is exactly the same as before. What you have done is fit a shower head that is less restrictive to flow than before.

Cheers

keystone

paulmapp8306 wrote: »

They claim to work from as little as 0.1Bar.

All this works down to 0.1 bar stuff is marketing nonsense. All too frequently on this board people complain that they have just fitted a nice new modern shiny tap with ceramic disc technology that has cost a small fortune and the water exiting the spout has reduced to a mere dribble. Thats because these continental taps are designed to operate with high pressure systems and the ceramic discs ae very restrictive to flow. But, hey, the tap still works because it delivers water. What the manufacturers should be doing is telling you what the flow rate will be at 0.1 bar assuming an input flow rate of n litres per minute. Pressure and flow rate are different, although connected, quantities.

Cheers

malc_b

southcoastrgi wrote: »

it's the bottom of the tank you measure from not the top of the water level

No. Water pressure is the head of water, otherwise there would be zero pressure at the bottom of a tank full of water Most showers say measure from the bottom of the cold water tank since that assumes that the flow is so high the cold water tank drains completely. In reality the level will drop but not all the way to the bottom.

paulmapp8306 wrote: »

Check the Mira showers. They claim to work from as little as 0.1Bar.

Just about all showers I've seen quote at 0.1bar and some higher figure. My question is are there any others that claim around 10 l/min at 0.1bar? Others seem to be 3-5 l/min.

keystone wrote: »

If you don't provide the shower with a decent flow rate it won't produce one magically out of thin air. You don't have enough head. You need a pump IMO.

I get a decent shower at the moment with a bath mixer. I'm just looking for a shower that can achieve the same.

keystone wrote: »

All this works down to 0.1 bar stuff is marketing nonsense. All too frequently on this board people complain that they have just fitted a nice new modern shiny tap with ceramic disc technology that has cost a small fortune and the water exiting the spout has reduced to a mere dribble.

I'm not sure on point here. Not all taps (or showers) are the same. I've seen basin taps where is says works best with 1bar (i.e. 10m head so fix these only on mains water or a pressured system). In a normal house you have ~0.2bar (2m) at a basin. Naturally if you fit a tap which says best on 1bar you're going to be disappointed.

malc_b

In case anyone with similar issues finds this thread I'll add a link to my blog page where I have put details of my setup, pipe runs, sizes; the shower I went for; and the performance results. These are here:

http://www.fullcircuit.com/blog/low-pressure-shower