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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> Water head https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1136572822 Message started by gullrock on Jan 6^th, 2006, 6:40pm

Title: Water head
Post by gullrock on Jan 6^th, 2006, 6:40pm

Advice please!!

I am installing a hot water tank in a flat and considering placing the cold tank on staging above it (the ceiling is about 9 foot high so allowing about 9inches for access etc the water level should be at about 7ft 6in - 8 ft). The kitchen taps are about 4 foot below the cold tank water level.

Will that set up give a sufficient head? Ther is no shower - only a bath and hand basin.

There is no room for a cold tank in a loft and I do not really want to go to the expense of installing a pressurized system either.

On the question of type of HW tank for this E7 set up. Is a combination much better than using 2 tanks as proposed?

Secondly, is there much advantage in using a specific E7 tank?

Title: Re: Water head
Post by billythekid on Jan 6^th, 2006, 7:17pm

You should have plenty head for a bath/basin, wont be blasting out the taps but then I guess you aren't expecting miracles. I wouldn't say a combination cylinder would be better, although this is the most common installation of them, flats. If you can get more head with a seperate tank then thats the way to go imo.

it'll help too if all this is as close to the Point of Use as possible.

btk

Title: Re: Water head
Post by thescruff on Jan 6^th, 2006, 7:47pm

Remember you can also get a good volume of water by installing larger then normal pipes

Title: Re: Water head
Post by gullrock on Jan 6^th, 2006, 8:03pm

Ok thanks - tanks will be very close to bathroom and I will use 22mm to bath, but probably only 15mm to sink which is only about 12 foot away and with Hep2o will not have any elbows or joints. Presumably if I use a combination H/C water tankthe whole thing would need to be raised as high as possible on staging?

Any views on the the extra expense of an economy 7 tank over an ordinary one please?

Title: Re: Water head
Post by billythekid on Jan 6^th, 2006, 8:17pm

yeah put the whole thing as high as possible to keep your head of water>pressure up.

Whats an economy 7 tank? i thought economy 7 was an electrical tariff for white metre heating and the like. ??

btk

Title: Re: Water head
Post by Lurch on Jan 6^th, 2006, 8:21pm

wrote on Jan 6^th, 2006, 8:17pm:

Whats an economy 7 tank?

I've been wondering that, standard tank but with 2 immersion bosses?

Title: Re: Water head
Post by Lectrician on Jan 6^th, 2006, 8:31pm

An Econ 7 tanks has positions for two elements - top and bottom. Bottom for off peak, and top for a boost on-peak.

Title: Re: Water head
Post by gullrock on Jan 6^th, 2006, 9:13pm

Plumb centre catalogue lists Grade 3 ( part L compliant) and also Economy 7 (part L compliant) the E7 one is more expensive!!

Title: Re: Water head
Post by billythekid on Jan 6^th, 2006, 9:52pm

ahh i know the ones. I think they are pretty good, although I wouldn't think they were that energy efficient. they heat and store a lot of water.

How come you dont want to throw in a combi gullrock?

btk

Title: Re: Water head
Post by Lectrician on Jan 6^th, 2006, 9:54pm

Assuming lack of gas supply??

Oil and LPG can also be diffcult in flats, or in areas with little road access.....

Title: Re: Water head
Post by gullrock on Jan 6^th, 2006, 10:56pm

No gas here, and electricity is likely to be the cheapest installation option. Flat on 1st floor so difficult for oil or gas tank anyway.

Should I fit a HW tank with 2 separate immersions (top one for day boost?

Title: Re: Water head
Post by billythekid on Jan 6^th, 2006, 11:01pm

OK that's me on the same page now! LOL. i would say yes. This is a pretty common way of doing things up here.

btk

Title: Re: Water head
Post by Lurch on Jan 6^th, 2006, 11:02pm

wrote on Jan 6^th, 2006, 10:56pm:

Should I fit a HW tank with 2 separate immersions (top one for day boost?

Have you got economy 7?

Title: Re: Water head
Post by gullrock on Jan 6^th, 2006, 11:30pm

Have you got economy 7?

Yes - already installed

Title: Re: Water head
Post by Lurch on Jan 7^th, 2006, 12:01am

Go for an economy 7 tank then. :)

Title: Re: Water head
Post by gullrock on Jan 7^th, 2006, 9:02am

ok thank you, I will probably use a combination tank too

Title: Re: Water head
Post by CWatters on Jan 7^th, 2006, 2:34pm

I believe the pressure you get is 0.1 bar per meter head of water so you will need taps designed for very low pressure.

Later edit: I think I would make sure I did the installation so that if pressure and flow was a problem I could easily install a pump eg without having to rip out the existing installation.

http://www.pumpexpress.co.uk/pump_ex_whole_house_boosting.htm

Title: Re: Water head
Post by sparkyjonny on Jan 9^th, 2006, 11:05am

I've got a setup similiar to what you describe in a flat. Pressure is sufficient but not ideal. I tried a shower which fits onto the taps but is only sufficient for low-level usage (washing hair over the side of the bath). Depends on the standard of the rest of the work - ie: whether it is to be marketed as a premium flat or standard/budget one.