Boosting mains pressure - suck or blow?

[DevsAd]

Hi.

I've been looking for info from websites of various manufacturers of mains booster pumps - Salamander, S-T and Grundfos, etc - and also that of some 'specialist' suppliers like 'pumpexpress.co'.

I'm trying to get a definitive answer to; "Can you suck as well as you can push'? Ie, how much does it matter whether you pump the mains water up from the ground level as opposed to drawing the mains water up from above?

This is for a 5th-floor flat, which makes it - what? - around 20 metres high? The current mains supply at the flat is 6lpm at best, and the pressure is under 1 bar. This isn't enough to refill the CWS quickly enough (and at peak times it's worse than this).

It might be possible (checking for a power supply in the basement) to fit a 12lpm booster pump at ground level (which pumpexpress says is the best/only way to do it) but the manufacturers of these types of pumps seem reckon it'll work fine by 'sucking' from above.

Has anyone any experience of this type of situation?

Thanks.

 

[Last Plumber]

Hi.

I've been looking for info from websites of various manufacturers of mains booster pumps - Salamander, S-T and Grundfos, etc - and also that of some 'specialist' suppliers like 'pumpexpress.co'.

I'm trying to get a definitive answer to; "Can you suck as well as you can push'? Ie, how much does it matter whether you pump the mains water up from the ground level as opposed to drawing the mains water up from above?

This is for a 5th-floor flat, which makes it - what? - around 20 metres high? The current mains supply at the flat is 6lpm at best, and the pressure is under 1 bar. This isn't enough to refill the CWS quickly enough (and at peak times it's worse than this).

It might be possible (checking for a power supply in the basement) to fit a 12lpm booster pump at ground level (which pumpexpress says is the best/only way to do it) but the manufacturers of these types of pumps seem reckon it'll work fine by 'sucking' from above.

Has anyone any experience of this type of situation?

Thanks.

Can you not have a tank installed at ground level and a twin pump set to supply to the floors?

 

[DevsAd]

Many thanks, LP.

The issue we have is that there's no electrical power in the basement, but we are looking at resolving this (it's a block of converted flats, and the mains water comes in under the pavement in a small open basement-type room).

If we can get power in there, then we'd definitely go ahead and fit a booster pump there, and this would then improve the mains flow to our flat 5 floors up.

However, I'm looking at alternatives just in case we cannot get power to the basement. In this case, we'd have to 'suck' the water up from above.

Would a mains booster pump mounted at the 'top' like this work ok?

Cheers.

 

[Last Plumber]

Many thanks, LP.

The issue we have is that there's no electrical power in the basement, but we are looking at resolving this (it's a block of converted flats, and the mains water comes in under the pavement in a small open basement-type room).

If we can get power in there, then we'd definitely go ahead and fit a booster pump there, and this would then improve the mains flow to our flat 5 floors up.

However, I'm looking at alternatives just in case we cannot get power to the basement. In this case, we'd have to 'suck' the water up from above.

Would a mains booster pump mounted at the 'top' like this work ok?

Cheers.

Never seen it done that way and you need permission to pump direct from a water main anyway. (you do in my part of the world). They won't let you pump more than 12 lpm either I don't think.

Best thing as I said before would be a correctly sized storage tank to supply the building and a twin head/set of pumps to serve. (like a Ship or launderette).

 

[DevsAd]

Cheers LP.

There are purpose-made mains pumps that are limited to 12lpm, and these are approved for use on the mains.

(There's even a suggestion that water boards like Thames quite like them as it means they can keep their supply pressure down...)

 

[Last Plumber]

Cheers LP.

There are purpose-made mains pumps that are limited to 12lpm, and these are approved for use on the mains.

(There's even a suggestion that water boards like Thames quite like them as it means they can keep their supply pressure down...)

I know they exist.

A flow rate of 12 lpm is ok. If it were mine I would want more.
If a storage tank were an option, you would need to know the performance figures for the main at ground, in order to make a decision.

For an answer to the question over suction and delivery, your best bet is to ring the manufacturers with as much info as poss and ask them if it will work. Make sure you work out the height correctly and any pipe sizes and runs.

 

[DevsAd]

Thanks again, LP.

Yes, the flat itself will want a lot more than 12lpm, but that mains boost will only be used to refill the CWS more quickly, so the CWS can handle the actual flow to the flat's taps.

I've had confirmed that fitting such a mains booster pump at the 'top' is fine and should work, provided there is water there to be sucked in the first place!

Cheers.