PRV for electric shower?

[macka09]

Hi, any recommendations on a prv for a shower?

 

[PlumbBobBob]

pressure reducing valve or pressure relief ?

 

[macka09]

Reducing sorry.

 

[macka09]

Anyone?...

 

[SimonG]

Why do you need a prv?

 

[macka09]

Triton have said the flow rate to the shower is to much that's why it can't hear the water quick enough.

 

[SimonG]

Anything off the shelf. Screwfix and toolstation do them.

 

[macka09]

Thanks

 

[solutions]

Thanks

You can get small plastic flow restrictors that you can fit inside the final compression fitting prior to the shower like on some boilers. Just pick 1 that pairs the flow back to the reduced level needed. Seems excessive to fit a wopping great prv for an electric shower. Whats the flow rate like if you pipe it up in 8mm?

 

[macka09]

Good idea. Would the flow restrictor not be a manufacturers part?

 

[iiplumbing]

Good idea. Would the flow restrictor not be a manufacturers part?

Just to confirm an electric shower?

These babies have a fixed heat output on the coil. They rely on restricting flow to lower volumes to heat the water up to higher temperatures.

thus the "PRV" in this instance is the DIAL on the front of the unit indicating temperature, turn colder for more volume less heat and the other way for less volume more heat

It's down to the equation phi (pronounced fie) = MCP delta T

Phi = the rating of the coil in kw
M = mass flow rate of water
CP = specific heat capacity of water
delta T = the amount that the temperature of water is raised

8.5kw/ 4.2 x (40-5)

So to raise the water from 5 degC to 40 degC with an 8.5kw coil the flow rate will be 0.05l/s or 3.46 l/min

with a 9.5 coil flow rate will be 0.06 or 3.88l/min

The dial on the shower changes the volume flow rate, so that's your method of reducing volume to increase temp

Hope this helps

Russ

 

[macka09]

Good insight there. Turned out the lady actually had a mixer shower.