Limited space hot water system suggestions?
 

Hi,
I'm trying to find a hot water system that will fit into a
cabinet whose outside dimensions are 500mm wide, by about
2m high, 600mm deep.

I can find plenty of condensing gas boilers to fit, but I'm
having a lot of trouble finding a hot water cylinder (unvented
preferably)of about 400mm diameter.

I've looked at thermal store systems as well, but they are
also a tad too wide. Range have a 350mm one, but it's a
rediculous 1750mm high, no room for the boiler then.

I think to fill a reasonable size bath I'll need about 150L
capacity.

Can anybody suggest something?

Cheers,
Mark.

On Tue, 28 Dec 2004 22:51:36 +0000, mark wrote:

Hi,
I'm trying to find a hot water system that will fit into a
cabinet whose outside dimensions are 500mm wide, by about
2m high, 600mm deep.

I can find plenty of condensing gas boilers to fit, but I'm
having a lot of trouble finding a hot water cylinder (unvented
preferably)of about 400mm diameter.

I've looked at thermal store systems as well, but they are
also a tad too wide. Range have a 350mm one, but it's a
rediculous 1750mm high, no room for the boiler then.

I think to fill a reasonable size bath I'll need about 150L
capacity.

Can anybody suggest something?

Cheers,
Mark.


You can get them made to size, but unfortunately you can't fit a quart
into a pint pot.....



--

..andy

To email, substitute .nospam with .gl

Andy Hall wrote:

I'm trying to find a hot water system that will fit into a
cabinet whose outside dimensions are 500mm wide, by about
2m high, 600mm deep.

[ ... ]

I think to fill a reasonable size bath I'll need about 150L
capacity.


You can get them made to size, but unfortunately you can't fit a quart
into a pint pot.....


In case that wasn't clear enough... let's do some scary multiplication,
in scary units called "decimeters". There's 10 dm in one m (hence 10cm
and 100mm in one dm). And a cubic dm is (to all reasonable purposes) a
litre. So the outside space here is 5 x 6 x 20 dm, giving a total cubic
capacity of 600dm or 600l - so the tank'd have to take a quarter of the
gross volume, more like a third of the internal volume once you've got
cupboard doors, sides, and (oh) access space for the boiler.

If you get a custom-made rectangular tank, the biggest cross-section it
could reasonably take would be say 4dm wide x 5dm deep, leaving sthg
under 10cm of access space for pipework around two of its four sides,
and covering it with superhypercelotex to get maximum insulation for
minimum thickness. To get your 150l with a cross-section of 20 sq dm,
you need a height of 7.5 dm - more like 9-10 dm once you allow for more
realistic access around it. That's half your height spent on the tank.
Can you fit the boiler into the remaining 1m of height? Sounds at best
expensive, cramped, and hot.

I think you'll have to settle for a combi, or find space for a tank
somewhere else!

Hi Stefek,
Thanks for the reply. Your calculations don't look so bad
actually. If the cabinet is 600L then I should be able to
get a 120L tank in there plus a boiler :)

I'm loathed to make the cabinet 600mm wide because it eats
into my dining area in the kitchen which is already tight.

I've been looking at combi's as another poster suggested.
The main problem with them is the pathetic flow rate of
the condensing models (which seems to be worse than the
older more inefficient models).

However, I have done some calculations and I think I only
need 16kW worth of central heating as the flat is 8x10m.

So if I want to improve the flow rate to something reasonable
then I need a boiler that's far too big - 30kW+ !!!

Is there another solution maybe? One with low central heating
power and high flow rate? Some kind of hybrid system?

Any thoughts appreciated.

Kind Regards,
Mark Jordan.




Stefek Zaba wrote:
Andy Hall wrote:

I'm trying to find a hot water system that will fit into a
cabinet whose outside dimensions are 500mm wide, by about
2m high, 600mm deep.

[ ... ]


I think to fill a reasonable size bath I'll need about 150L
capacity.


You can get them made to size, but unfortunately you can't fit a quart
into a pint pot.....


In case that wasn't clear enough... let's do some scary multiplication,
in scary units called "decimeters". There's 10 dm in one m (hence 10cm
and 100mm in one dm). And a cubic dm is (to all reasonable purposes) a
litre. So the outside space here is 5 x 6 x 20 dm, giving a total cubic
capacity of 600dm or 600l - so the tank'd have to take a quarter of the
gross volume, more like a third of the internal volume once you've got
cupboard doors, sides, and (oh) access space for the boiler.

If you get a custom-made rectangular tank, the biggest cross-section it
could reasonably take would be say 4dm wide x 5dm deep, leaving sthg
under 10cm of access space for pipework around two of its four sides,
and covering it with superhypercelotex to get maximum insulation for
minimum thickness. To get your 150l with a cross-section of 20 sq dm,
you need a height of 7.5 dm - more like 9-10 dm once you allow for more
realistic access around it. That's half your height spent on the tank.
Can you fit the boiler into the remaining 1m of height? Sounds at best
expensive, cramped, and hot.

I think you'll have to settle for a combi, or find space for a tank
somewhere else!

On Wed, 29 Dec 2004 00:04:46 +0000, Stefek Zaba wrote:

Andy Hall wrote:

I'm trying to find a hot water system that will fit into a
cabinet whose outside dimensions are 500mm wide, by about
2m high, 600mm deep.

[ ... ]

I think to fill a reasonable size bath I'll need about 150L
capacity.


You can get them made to size, but unfortunately you can't fit a quart
into a pint pot.....


In case that wasn't clear enough... let's do some scary multiplication,
in scary units called "decimeters". There's 10 dm in one m (hence 10cm
and 100mm in one dm). And a cubic dm is (to all reasonable purposes) a
litre. So the outside space here is 5 x 6 x 20 dm, giving a total cubic
capacity of 600dm or 600l - so the tank'd have to take a quarter of the
gross volume, more like a third of the internal volume once you've got
cupboard doors, sides, and (oh) access space for the boiler.

If you get a custom-made rectangular tank,

That's the chink AIUI in this argument. The only tanks I've seen in this
shape are made of steel. Even the ones which look rectangular in the
pre-plumbed units popular in 70's flats (Harcopak etc.) actually have
cylinders inside a box of foam insulation.

You could probably get a standard cylinder in if you carve off the
insulation at the sides, a bit of a pig to fit though.
In my own house I fitted a 375mm+insulation diameter cylinder and with the
modern fast recovery coil it can produce a bath full every 15 mins.

375x900 is about 100 litres and should be adequate for most homes.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

On Thu, 30 Dec 2004 20:48:11 +0000, mark wrote:



So if I want to improve the flow rate to something reasonable
then I need a boiler that's far too big - 30kW+ !!!

Is there another solution maybe? One with low central heating
power and high flow rate? Some kind of hybrid system?

Any thoughts appreciated.

Kind Regards,
Mark Jordan.



I'm not suggesting that you do it necessarily, but you can get combis
of 45kW and more if flow rate is the issue and space that tight. THe
heating aspect isn't really an issue because the boiler will modulate
down anyway.

THey tend to be big beasts though.....





--

..andy

To email, substitute .nospam with .gl

Ed Sirett wrote:

In my own house I fitted a 375mm+insulation diameter cylinder and with the
modern fast recovery coil it can produce a bath full every 15 mins.

375x900 is about 100 litres and should be adequate for most homes.

Do you have details of who makes this cylinder Ed?

Thanks!
Mark.

On Thu, 30 Dec 2004 22:31:20 +0000, mark wrote:

Ed Sirett wrote:

In my own house I fitted a 375mm+insulation diameter cylinder and with the
modern fast recovery coil it can produce a bath full every 15 mins.

375x900 is about 100 litres and should be adequate for most homes.

Do you have details of who makes this cylinder Ed?

Thanks!

I simply asked for it my regular plumber's merchant, it came in within 2
days.

The unit was likely made by IMI.

I'll ask if I remember who the supplier/maker is next time I call at the
shop. It may well be that the merchant simply uses a wholesaler who hole a
greater stock range.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html