Water and Heating Design Options

[Agile]

Lee is not giving a realistic idea of costs!

Homebooster at £720+vat is only the supply price. Then there is installation cost.

They probably come with about 100 litres of storage. That would give about one bathfull and just one minute of showering!

You will need a minimum of 300 litres of pumped cold storage and 300 litres of hot storage. Not at all impossible but not so cheap either.

Even that will only run your bath and the two showers together for about 10 minutes. Increase the storage to 500 litres if you want to have longer showers.

Tony

 

[Biggles..]

A small bit of advice to Mr TG, before commenting that people are misleading all think:

If you have never heard of/or fitted an item please check the manufacturers website just to have a look at what your wriitng about.

Grunfos homebooster 200litre storage cold water booster.
Fitting is 15mm cold inlet 22 cold outlet,only extra item required is a PRV because the unit runs as an accumalative store.

Each unit has a connection on the back for additional blank store to be added.

designed soley for the domestic/small commercial market as a one stop package for boosting.
Far easier and simpler to install and commision than a CWS,twin booster set with decent active driver controls.

As the OP commented that the unit looks expensive i gave the costs.Installation costs vary, certainly if your charging £1000-2000 for a MDPE main upgrade i'd be looking at other alternatives.

Lee

 

[doitall]

Plenty of talk about a 50Kw combi, if you go for the break tank and pump set, you can size the boiler for the heating load, maybe nearer 15Kw, and save a fortune on the boiler and running cost.

Maintenance is also considerable cheaper, as system boilers are much more reliable.

Another bonus is an immersion back-up.

 

[GeorgeWBush]

Really appreciate all this input

Alternatively to a tank & pumping - would a large accumalator (or 2) be an option for me? Something like coldstream http://www.gah.co.uk/heating/coldstream/faqs.php

My supply figures were 2.5 bar 15 ltr/min, measured at garden tap.

 

[doitall]

Before you decide anything, you need to calculate the total expected demand, and share it with 25% cold.

An accumulator will not improve on the 15Ltrs/m, unless you fit the pump type.

Experience says there's only one way to get 30Ltrs/m plus, and that is with a break tank and pump set, and if you have the space in the garage it would be ideal, with the tank, pump set, unvented cylinder, and boiler all in on place.

 

[GeorgeWBush]

need to calculate the total expected demand, and share it with 25% cold

Doitall - could you explain this a little further please? Are you saying, for example, if i estimate i will need 30 ltrs/m, 7.5 ltrs of this would need to be cold and the other 22.5 ltrs hot?

 

[doitall]

need to calculate the total expected demand, and share it with 25% cold

Doitall - could you explain this a little further please? Are you saying, for example, if i estimate i will need 30 ltrs/m, 7.5 ltrs of this would need to be cold and the other 22.5 ltrs hot?

More or less, yes, it depends what temperature and type of system you go for, but you need to allow a percentage.

If for example a shower will deliver 12 Ltrs/m, you could say 9 hot x 3 cold, subject to the above. Therefore the mains would have to deliver 12Ltrs/m and the boiler 9Ltrs/m.

With what you're planning you could be looking at 4 times that.

 

[Agile]

If you could just fill your bath before starting the showers that would significantly reduce your problems!

Bath filling 20 li/min for 6 minutes. After that you could run your two showers at 10 li/min of hot and say 2 li/min each. That will halve your mains supply flow requirement.

The Grunfoss home booster stores 180 li of water but you will need at least twice that whatever you do. Its flow rate is totally adequate but I doubt you will buy it as cheap as Lee suggests. Nor does it allow for the mark-up which many installers expect to make. They are also rather noisy and only really suited to garage or basement installation.

A mains water supply upgrade makes no noise, consumes no power and continues to work during the frequent power cuts you seem to have!

Tony

 

[GeorgeWBush]

A mains water supply upgrade makes no noise, consumes no power and continues to work during the frequent power cuts you seem to have!

Is there a way to estimate the flow I am likely to get after a line upgrade based upon my current supply figures?

 

[Agile]

Thats the problem!

But with a 35mm pipe and 2.5 Bar static pressure it should be good. The water Co might increase the standing charge though.

If you measure the distance to the supply pipe in the street and tell us what its made of now then we could guess.

I am currently doing a job at a 1st floor flat with a 15 mm supply pipe which gives 47 li/min !

I did not believe him when he first told me by email and asked him to measure it again!

Tony

 

[dextrous]

A bucketful every 20 seconds. That's some going. Take it you're not working on it live then