If installing a unvented cylinder your requirement is to run 2 showers together?, you will still need a CWST IMO with a single ended pump as difficult to imagine a mains supply of ~ 30LPM @ say 2.0/2.5bar dynamic pressure.I didn't know what a Jab was so had to look it up
From reading other threads Joule seems to crop up quite often as a recommendation.
I've got in touch with the chap who replaced the boiler 6 Months ago, to see if he would be prepared to carry out the works.
Should I have a pumped shower?
- Thread starter LeeJC
- Start date
Isn't the point of an unvented HW cylinder that you can have a mains-pressure shower?
Yeah I think that's entirely the point. I'm not sure what purpose a CWST would serve in a unvented cylinder installation, other than to make it vented.....
Where would you feed into the tank?
Are you suggesting pressurising the CWST with a pump to then feed into the unvented cylinder?
Don't most/all unvented systems come with a 3 Bar regulator?
Isn't Pipe size also involved in flow rate?
I've got over 3 bar in my current property, the flow from the kitchen tap on a pair of 8mm tails is 15LPM, the Bath Taps on 22mm are at 30LPM.
I think if going unvented I wouldn't be looking for a CWST to be involved at all, certainly not one that's pumped and likely to end up in competition with the mains feed requiring all manner of non return valves.
Unvented is fine IMO for running one shower but running two together??, your bath taps are running 30LPM but a shower(s) TMV and shower head will require ~ 1.0/1.5bar extra dynamic pressure, the mains pressure here is generally much lower than in the UK and single ended pumps are very often used in your example but everything is pumped, pumped unvented cylinder HW does not mix with mains cold, others use a double ended pump with a vented cylinder.
I can happily run 3 - bar showers (with ~ 27L/min @ ~ 3.3 bar dynamic) from a 250L unvented at the same time, yes there is a little drop in pressure when all 3 are on but they are more than acceptable.
You need a proper survey of the mains supply and you need to know a true dynamic figure at an unrestricted outlet as a starting point - kitchen taps tend to have aerators/restrictors etc An outside tap that is fed from close to the mains pipe is an ideal place.
You need a proper survey of the mains supply and you need to know a true dynamic figure at an unrestricted outlet as a starting point - kitchen taps tend to have aerators/restrictors etc An outside tap that is fed from close to the mains pipe is an ideal place.
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