Mike:

Why does shower waste need to be roddable ?

I suppose technically it doesnt if youre wiling to risk replumbing it.
Preferable to make it maintainable I think.



IMM:

You can make your own using two large bore copper pipes. One inside
the
other. The mains water is in the gap between the two. Using two
reducing
elbows and filing out the pipe stops inside the the fittings so the
inner
pipe can slip you can easily make one yourself. Once filed out you
solder
it up with a powerful blowtorch and wrap with insulation.

Have you actually done this, at 20ft long? The reason I didnt suggest
this approach is differential thermal expansion. I cant imagine how a
soldered joint would survive in such a creation. Sounds like a real
recipe for leakage to me. One could certainly do it with flexible
copper tube, but I dont know where youd get that in such a large size.


- 1 three metre lengty of 22mm pipe
- 1 three metre lengty of 15 mm pipe

why do you recommend 3m? And more to the point, why 20ft? Theyre
usually 2-3ft.


- Solder up.

why do you recommend solder, which is soft and cracks easily, when the
2 tubes have differential thermal expension?


- Cover with insulation.

why do you recommend insulation? I'm not clear why cold to lukewarm
flow, which is what goes round the outside, would need insulation. Most
of the time it just sits there cold. I would think insulation might
trap condensate and cause mould.

I think if youve got insulation to play with there would be much more
effective places to put it.


You size up the copper pipe to suit eithe a shower or a full 110mm
waste.

Where do you get the 110mm copper fittings? And how do you drill 110mm
holes in them?



Brian:

BTW, a 'new' bathroom is on the list once I've
got the correct tuits - I've indicated to my wife that I've only got
square tuits left from the last big-job - So I'm genuinely interested
in heat-recovery devices as I'm always annoyed when joules of
decent heat-energy goes down the plug-hole after each bath.
I'd also be interested in where-abouts the tepid (cold) water
could be introduced into the domestic-hot-water system.


You've got 2 options for the warmed water, and 2 options for the drain
water.

warmed water can go either:
to the cold input of the shower
or to the cold fill on the house's hot tank.

And the waste side can handle either:
the output from the shower
or the total grey water drain output of the whole house.

The logical thing is to have it either handling shower in and shower
out, or house in and house out.


_________________// preheating
___/__________________\____
___________________________ drain
\ _________________/
//


Fitting vertically gives ideal performance, but they also work well
horizontal too.
Note the 2 flows should go in opposite directions to get effective heat
exchange.



Mark:

FFS how many showers do you people have a day.
Has anyone given the slightest thought to how efficient this will be,
and
the likely rise in temperature achievable.

Of course. The payback is around 100% pa if youve got 4 people in the
house. Thats why we're talking about putting them in during a refit.
NT

Another know-it-all. Do a Google on groups and type in gfx. If you
did
that first you wouldn't nake such an idiot of yourself. There are some
Americans who have these installed and reported figures on them. The
average
temp rise is 17C. In effect it makes your cylinder bigger too. When
showering they are effective because you are heating the incoming cold
water
with waste water simultaneously.

Domestic applications have a far loger payback than commercial. Heavy
use
of waste water would make it feasible, in places sucj as hotels. Make
your
own, as in solar panels, and the payback is quite quick. See my post
on
making one.


So if you have a combi that gives 11 litres/min @:35C temp rise, then
having
one of these pre-heating the mains water to the combi will give and
extra
50% temperature rise. In effect making that 11 l/min to approx 17
litres/min


Its funny, but he's quite right.

NT

wrote in message
oups.com...
Another know-it-all. Do a Google on groups and type in gfx. If you
did
that first you wouldn't nake such an idiot of yourself. There are some
Americans who have these installed and reported figures on them. The
average
temp rise is 17C. In effect it makes your cylinder bigger too. When
showering they are effective because you are heating the incoming cold
water
with waste water simultaneously.

Domestic applications have a far loger payback than commercial. Heavy
use
of waste water would make it feasible, in places sucj as hotels. Make
your
own, as in solar panels, and the payback is quite quick. See my post
on
making one.


So if you have a combi that gives 11 litres/min @:35C temp rise, then
having
one of these pre-heating the mains water to the combi will give and
extra
50% temperature rise. In effect making that 11 l/min to approx 17
litres/min


Its funny, but he's quite right.

I always am...

Its funny, but he's quite right.
I always am...

mops up drink from keyboard...

--
Please add "[newsgroup]" in the subject of any personal replies via email
--- My new email address has "ngspamtrap" & @btinternet.com in it ;-) ---

From:
Subject: DIY solar heating
Date: 24 January 2005 18:06


You can make your own using two
large bore copper pipes. One inside
the other. The mains water is in the
gap between the two. Using two
reducing elbows and filing out the
pipe stops inside the the fittings so the
inner pipe can slip you can easily make
one yourself. Once filed out you
solder it up with a powerful blowtorch
and wrap with insulation.

Have you actually done this, at 20ft long?

Yep.

The reason I didnt suggest
this approach is differential thermal #
expansion. I cant imagine how a
soldered joint would survive in such a creation.

Thermal expansion is not that great.

Sounds like a real recipe for
leakage to me.

Nope. Works well.

- 1 three metre lengty of 22mm pipe
- 1 three metre lengty of 15 mm pipe

why do you recommend 3m?

An e.g, and they come in 3 metre lengths.

And more to the point, why 20ft? Theyre
usually 2-3ft.

An e.g., from an different application.

- Solder up.

why do you recommend solder,
which is soft and cracks easily, when the
2 tubes have differential thermal expension?

It worked well. You could use compression joints tightly screwed up.

- Cover with insulation.

why do you recommend insulation?

Are you serious?

I'm not clear why cold to lukewarm
flow, which is what goes round the
outside, would need insulation.

You are serious.

You size up the copper pipe to suit
either a shower or a full 110mm
waste.

Where do you get the 110mm copper
fittings?

Nearest equiv and from industrial merchants.

And how do you drill 110mm
holes in them?

You don't drill, you use fittings as described above.

"IMM" wrote in message
...
- Solder up.

why do you recommend solder,
which is soft and cracks easily, when the
2 tubes have differential thermal expension?

It worked well. You could use compression joints tightly screwed up.

How the **** are you going to slide a compression joint inside the outer
pipe ?

"Mike" wrote in message
...

"IMM" wrote in message
...
- Solder up.

why do you recommend solder,
which is soft and cracks easily, when the
2 tubes have differential thermal expension?

It worked well. You could use compression joints tightly screwed up.

How the **** are you going to slide a compression joint inside the outer
pipe ?

Please read posts again. It was clear.

"Mark" wrote in message
...
IMM typed:

FFS how many showers do you people have a day.
Has anyone given the slightest thought to how efficient this will
be, and the likely rise in temperature achievable.
Even I cant be bothered to build one of these.

Another know-it-all. Do a Google on groups and type in gfx. If you
did that first you wouldn't nake such an idiot of yourself. There
are some Americans who have these installed and reported figures on
them. The average temp rise is 17C.

Must be

Even the US government is on about it.

http://www.eere.energy.gov/femp/pdfs...ty_film_ex.pdf

"IMM" wrote in message
...

"Mark" wrote in message
...
IMM typed:

FFS how many showers do you people have a day.
Has anyone given the slightest thought to how efficient this will
be, and the likely rise in temperature achievable.
Even I cant be bothered to build one of these.

Another know-it-all. Do a Google on groups and type in gfx. If you
did that first you wouldn't nake such an idiot of yourself. There
are some Americans who have these installed and reported figures on
them. The average temp rise is 17C.

Must be

Even the US government is on about it.

http://www.eere.energy.gov/femp/pdfs...ty_film_ex.pdf

The US government conclude:

"however, based on our measurements, a 30 to 50% savings in the energy
needed to heat shower water seems reasonable."

IMM typed:

FFS how many showers do you people have a day.
Has anyone given the slightest thought to how efficient this will
be, and the likely rise in temperature achievable.
Even I cant be bothered to (use) one of these.

Another know-it-all. Do a Google on groups and type in gfx. If
you did that first you wouldn't nake such an idiot of yourself.
There are some Americans who have these installed and reported
figures on them. The average temp rise is 17C.

Must be distant Dimm relatives of yours,

Even the US government is on about it.

http://www.eere.energy.gov/femp/pdfs...ty_film_ex.pdf

The US government conclude:

"however, based on our measurements, a 30 to 50% savings in the energy
needed to heat shower water seems reasonable."

sigh
ive built two of these, BP1 was 25m ( note 25 meters !) of 8mm pipe coiled
inside a 150mm soil pipe with stop-ends fitted with 1-1/2 waste fittings to
connect to shower 3ft away, cold water flow was set to 1gpm.
After running hot shower for 15 min to ensure everything had warmed up I
measured the input and output temperatures, the gain was a staggering
................ 1 deg C

Having realised I need a MUCH bigger heat exchanger came BP2.
This one would be completely impractical to actually use but..
A friend was ripping out a warm-air CH boiler, Ah that looks big enough.
So I built a tank to hold HE and arranged plumbing so the tank filled with
warm water before exiting, same flow rate and test as before.
The gain in temp was 4 deg C

Conclusion, don't bother unless you are chucking huge amounts of hot water
down the drain, fit solar panels instead.

(Dimm design quote: 1 three metre lengty of 22mm pipe, still making me LOL )

--
Mark

"Mark" wrote in message
...
IMM typed:

FFS how many showers do you people have a day.
Has anyone given the slightest thought to how efficient this will
be, and the likely rise in temperature achievable.
Even I cant be bothered to (use) one of these.

Another know-it-all. Do a Google on groups and type in gfx. If
you did that first you wouldn't nake such an idiot of yourself.
There are some Americans who have these installed and reported
figures on them. The average temp rise is 17C.

Must be distant Dimm relatives of yours,

Even the US government is on about it.

http://www.eere.energy.gov/femp/pdfs...ty_film_ex.pdf

The US government conclude:

"however, based on our measurements, a 30 to 50% savings in the energy
needed to heat shower water seems reasonable."

sigh
ive built two of these, BP1 was 25m ( note 25 meters !) of 8mm pipe coiled
inside a 150mm soil pipe with stop-ends fitted with 1-1/2 waste fittings
to
connect to shower 3ft away, cold water flow was set to 1gpm.
After running hot shower for 15 min to ensure everything had warmed up I
measured the input and output temperatures, the gain was a staggering
............... 1 deg C

Having realised I need a MUCH bigger heat exchanger came BP2.
This one would be completely impractical to actually use but..
A friend was ripping out a warm-air CH boiler, Ah that looks big enough.
So I built a tank to hold HE and arranged plumbing so the tank filled with
warm water before exiting, same flow rate and test as before.
The gain in temp was 4 deg C

Conclusion, don't bother unless you are chucking huge amounts of hot water
down the drain, fit solar panels instead.

You are obviously and idiot and did it wrong...and can't read either. The
US governments tested it and says: "The key to this patented device was the
inventor's observation that wastewater clings in a film-like fashion to the
inside wall of the pipe as it undergoes gravity flow in the open drain, and
this warm, falling film transfers heat through the pipe"

The pipe has top be "smooth" in the inside. Boy are you dumb!