What size pump do I need?

[DIYBlues]

Hi Guys

I have to install two showers both thermostatically controlled and each specifies a minimum of 0.5bars of pressure. The two new shower heads also requires a minimum of 0.5bars. Do you have to add each of the requirements up totaling 2.0bars or is 0.5 the minimum of the whole system needs?
It is probable that both showers will be used at the same time.

I don’t want to use more than say 10 liters per minute per shower as on testing my current system we used just under 5 liters which has always given a reasonable shower but I guess this could be improved.

So my question is what size/type of pump should I use and do you recommend one?

Regards
Simon.

 

[gravytrain]

if you want to run two showers at a time you need to make sure the pump and the installation of it
can handle the flow required.

a good place to start is the salamander pumps website/helpline. you dont have to choose one of their
pumps but you will get an idea of what is required
its very likely you will have to fit an extra cold water tank to run two showers at the same time.

 

[Deleted member 44451]

i would agree with gravtrain if you talk to the pump manufacturers tell them what you have got they will tell you which pump to use , and also the cold water volume that you need in the storage tanks

 

[DIYBlues]

On checking the tank in the loft it says it 50 GAL 227 litres.

Is it only the cold water that runs through a pump or do I need one that does both hot and cold?

Cheers
Simon.

 

[Best]

You need what is called a twin pump - it has impeller at each side of pump motor.
This gives you equal pressure & flow for both hot & cold. If money not too tight, consider Stuart & Turner pumps. If you get, say, a 3bar pump that is a whole house pump, then it will do 2 showers easy. Be careful to check if negative or positive head pump required.
Check with pump manufacturers, as others say, & they will help. Not a job for a novice.

 

[DIYBlues]

Thanks for the replies so far

Are you saying that the installation of a pump is not a job for a novice?

I was thinking of incorporating a flow regulator like the one showen below to limit the flow rate



Would this work together?

Regards
Simon.

 

[Best]

Too be honest, I don't think plumbing is for novices, but that's not to say that a novice cannot do a decent job. Fitting a shower pump is a fairly big plumbing job often & complex.

On the flow reducer, - why? If the shower valves are dual lever type, they will have variable flow, so no need of restrictors. You are correct to think of using less water, as power shower flow rates on, or near max are crazy & a waste of water & energy. Try to chose dual control shower valves & lower flow shower heads if possible. Have it all done in copper pipe, with supply pipes fitted with full flow lever valves & hot supply temperature regulated + air free.