Plumbing Question

Water storage tank with negative head pump for 3 flats

Hello and thanks for reading my query.

I am looking to take a up a loft conversion. The property will be split into flats - 3 in total and rented out.

My question is regarding water pressure and usage.

My idea was to get a 32mm feed into the property and put up a storage tank in a section of unuseable space in the loft.

Loft flat will be electric only so I'd put in a megaflow tank.

1st floor flat will have independent system boiler with a megaflo tank.

Ground floor flat will have independent system boiler with a megaflo tank.

I want to ensure that I can have adequat pressure all through the different units.

Please let me have the right way to achieve this rather than my unprofessional idea.

Mains pressure is ok for a single dwelling with 2 shower.

Thank you.

James, if going the route of having a large storage tank, what pump should I be fitting? a negative head one with at least how many bars?
The apartment in loft will have a megaflo heated by electricity only. Central heating will be by electric oil radiators.
Rest of apartments will have system boiler and separate megaflo cylinders.

2 Answers

Hi - there are a a few things that need to be considered here.

If you already have 3 bar or more for water pressure, you do not need to have any of the above, fit all three flats with combi boilers and this will make huge savings.

However if you want to provide stored hot water, the mega flows are best and need to be operating at 3 bar. If you do not have this, then you will need a storage space large enough to hold 250/300 litres of water, which in turn will pump water to the megoflow.

Hope this helps, any questions please come back to me.

6th June - OK, if you need the storage tank, it would be a pressure tank or pressure vessel - no pump, its built in, your fitter would be able to advise, the make and size. Who ever is fitting the megaflow, will need to survey the building. You do know that Mega flows only work, with 3 bar of pressure - if you do not have this from the mains, then you are going to need tanks for all three flats.

I go back to my original point as I have fitted several flats with combi boilers, where the pressure is 3 bar, so there is no reduction in pressure/flow when using two or more taps.


Answered 5th Jun 2012

Rothwell James

Member since 24 Mar 2012

I know this is an old question but the other option to supplying the CWS required would have been to use an OSO Accumulator. There are some minimum requirements for them ie, min flow and pressure.

Answered 8th Apr 2013

AGL Heating & Building

Member since 1 Oct 2009

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