In alt.solar.thermal Rod Speed wrote:

What explanation is there for this heat requirement,

Basically storage hot water services can end up with
a significant problem if they arent run at a high enough
temperature to kill bacteria, in situations where the
water supply isnt chlorinated like with wells etc.

which doesn't exist in most other parts of the first world?

It does actually. Most obviously with Legionaire's Disease.

And the use of unchlorinated wells with residential
property is much more common in north america too.

I have lived on well water for many years. Some people treat water drawn
from shallow wells, but I don't know of anyone that does any treatment to
deep wells.

I find recommendations to raise the temperature to 170f to kill hydrogen
sulfide to get rid of a rotten egg smell, but even those sites say it is
harmless.

Most of the advice is to set the temperature to 140 if you have a
dishwasher, 120 otherwise.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

daestrom wrote:
"Robert Gammon" wrote in message
. net...
wrote:
Robert Gammon misunderstands again:
snip
Goto www.gfxtechnology.com/GFX-STAR.html and click on Application
Notes and click on the link to Retrofit of an existing Solar Hot
Water Heater. You sir, need to READ first, before you make accusations
that you
cannot back up with facts.

In there he describes a patent pending application of GFX Star in an
industrial process control application.

The models of what happens to the efficiency of his product with
changing potable water flows thru the equipment are there for all to
see.

Okay, *I* read the documents. It is clear that you must have a
separate storage tank for the GFX-star setup to work 'as advertised'.
Only by using a *cooler* separate storage tank is the setup able to
capture the waste heat from 'batch' drains. Once the storage tank
reaches the temperature of the greywater (or exceeds it in the
conventional heater storage tank), performance will drop off.

This way can effectively 'shift' the heat from outgoing batch drains
to a separate storage tank of fresh-water. So the greywater doesn't
have to be stored, and you can still use the low-maintenance,
straight-bore, GFX heat-exchanger.

For 'best' performance, you would want to route the storage tank
outlet to the 'cold' tap for the shower as well. This looks like
their 'tempering valve' arrangement. But you might be better off
routing straight 'cold' water from the supply directly to sinks and
laundry, bypassing the whole setup for cold supply to those usage
points. Otherwise you would be wasting some of the captured heat on
laundry, and who wants a glass of warm water to drink. Some more
plumbing :-(

Someone mentioned some concerns about storage tank of 'warm' water and
Legionarries disease. But if you have treated water, that probably
isn't too much of a concern.

It is with storage water heaters.

In tests of thousands of water heaters 40% were found to contain
lethal doses of legionella bacteria.

Further testing found that none of the water heaters were gas fired.
Only the electric heated units were the problem below the bottom
element.

I believe as long as the water is moving frequently and/or heated past
96F the legionella is rendered inert.


"Rod Speed" wrote in message
...
daestrom wrote:
"Robert Gammon" wrote in message
. net...
wrote:
Robert Gammon misunderstands again:
snip
Goto www.gfxtechnology.com/GFX-STAR.html and click on Application
Notes and click on the link to Retrofit of an existing Solar Hot
Water Heater. You sir, need to READ first, before you make
accusations that you
cannot back up with facts.

In there he describes a patent pending application of GFX Star in
an
industrial process control application.

The models of what happens to the efficiency of his product with
changing potable water flows thru the equipment are there for all
to
see.

Okay, *I* read the documents. It is clear that you must have a
separate storage tank for the GFX-star setup to work 'as
advertised'.
Only by using a *cooler* separate storage tank is the setup able to
capture the waste heat from 'batch' drains. Once the storage tank
reaches the temperature of the greywater (or exceeds it in the
conventional heater storage tank), performance will drop off.

This way can effectively 'shift' the heat from outgoing batch
drains
to a separate storage tank of fresh-water. So the greywater
doesn't
have to be stored, and you can still use the low-maintenance,
straight-bore, GFX heat-exchanger.

For 'best' performance, you would want to route the storage tank
outlet to the 'cold' tap for the shower as well. This looks like
their 'tempering valve' arrangement. But you might be better off
routing straight 'cold' water from the supply directly to sinks and
laundry, bypassing the whole setup for cold supply to those usage
points. Otherwise you would be wasting some of the captured heat
on
laundry, and who wants a glass of warm water to drink. Some more
plumbing :-(

Someone mentioned some concerns about storage tank of 'warm' water
and
Legionarries disease. But if you have treated water, that probably
isn't too much of a concern.

It is with storage water heaters.

Solar Flare wrote:

In tests of thousands of water heaters 40% were found to contain lethal
doses of legionella bacteria.

Further testing found that none of the water heaters were gas fired.

Bet that was just because so few of them were gas fired.

Only the electric heated units were the problem below the bottom element.

Because most codes mandate a minimum thermostat temp.

I believe as long as the water is moving frequently and/
or heated past 96F the legionella is rendered inert.

You're wrong on that last. Needs to be 140F

And there is no 'rendered inert', its either killed or it aint.


"Rod Speed" wrote in message
...
daestrom wrote:
"Robert Gammon" wrote in message
. net...
wrote:
Robert Gammon misunderstands again:
snip
Goto www.gfxtechnology.com/GFX-STAR.html and click on Application
Notes and click on the link to Retrofit of an existing Solar Hot
Water Heater. You sir, need to READ first, before you make
accusations that you
cannot back up with facts.

In there he describes a patent pending application of GFX Star in
an
industrial process control application.

The models of what happens to the efficiency of his product with
changing potable water flows thru the equipment are there for all
to
see.

Okay, *I* read the documents. It is clear that you must have a
separate storage tank for the GFX-star setup to work 'as
advertised'.
Only by using a *cooler* separate storage tank is the setup able to
capture the waste heat from 'batch' drains. Once the storage tank
reaches the temperature of the greywater (or exceeds it in the
conventional heater storage tank), performance will drop off.

This way can effectively 'shift' the heat from outgoing batch
drains
to a separate storage tank of fresh-water. So the greywater
doesn't
have to be stored, and you can still use the low-maintenance,
straight-bore, GFX heat-exchanger.

For 'best' performance, you would want to route the storage tank
outlet to the 'cold' tap for the shower as well. This looks like
their 'tempering valve' arrangement. But you might be better off
routing straight 'cold' water from the supply directly to sinks and
laundry, bypassing the whole setup for cold supply to those usage
points. Otherwise you would be wasting some of the captured heat
on
laundry, and who wants a glass of warm water to drink. Some more
plumbing :-(

Someone mentioned some concerns about storage tank of 'warm' water
and
Legionarries disease. But if you have treated water, that probably
isn't too much of a concern.

It is with storage water heaters.

In alt.solar.thermal Rod Speed wrote:

Those that know anything about Legionella dont.
http://www.ihf.ie/news/innsight/98-1...tm#anchor23477

Let's go back to Australia:
http://www.safetyline.wa.gov.au/page...dewswa0210.htm
"Long exposure at 50C or shorter exposure at higher temperatures is
sufficient to kill the bacteria." That would be 122F.

I remember The American Legion meeting, but that was warm water in a
cooling tower, not a domestic water heater.

"Proliferation of L. pneumophila is promoted by:
a wet warm environment (range 25-42C);
optimum temperature (35-37C);
stagnation or low water turnover;
high microbial concentration including algae, amoebae, slime and other
bacteria;
presence of biofilm, scale, sediment, sludge, corrosion products or organic
matter;
presence of certain materials such as natural rubber fittings which may be
a nutrient source. "

I don't think that describes my domestic water supply.
The recommendation for 120F still stands. That won't scald, and it will
kill Legionella bacteria.


--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

wrote
Rod Speed wrote
wrote

Most of the advice is to set the temperature to
140 if you have a dishwasher, 120 otherwise.

Those that know anything about Legionella dont.
http://www.ihf.ie/news/innsight/98-1...tm#anchor23477

Let's go back to Australia:

No thanks, that specification of the minimum temperature
that storage hot water heaters should be set to is just
about universal right thruout the first world now.

Because Legionella is a real problem with showers.

http://www.safetyline.wa.gov.au/page...dewswa0210.htm
"Long exposure at 50C or shorter exposure at higher temperatures
is sufficient to kill the bacteria." That would be 122F.

Thats on the low side of the recommendations,
60C, 140F is much more common.
http://www.google.com.au/search?q=Legionella+60+C

I remember The American Legion meeting, but that was
warm water in a cooling tower, not a domestic water heater.

Sure, and after that it was realised that storage
hot water services could be a real problem with
Legionella when they are set a lower temperatures
to avoid scalds with kids and the elderly etc.

Presumably we didnt see that much of problem with
Legionella in storage hot water systems because
most didnt deliberately turn back the setpoint much
before that American Legion meeting made it clear
what a problem that particular bacteria could be.

"Proliferation of L. pneumophila is promoted by:
a wet warm environment (range 25-42C);
optimum temperature (35-37C);
stagnation or low water turnover;
high microbial concentration including algae, amoebae, slime and other
bacteria;
presence of biofilm, scale, sediment, sludge, corrosion products or
organic matter;
presence of certain materials such as natural rubber fittings which
may be a nutrient source. "

Thats just cooling towers, different animal
entirely to storage hot water services.

I don't think that describes my domestic water supply.

See above.

The recommendation for 120F still stands.

No it doesnt if you actually have a clue about Legionella

That won't scald, and it will kill Legionella bacteria.

Have fun explaining the common code requirement of 60C, 140F

http://www.dhmh.state.md.us/html/legionella.htm
says you are just plain wrong using rigorous science.

Do your comments represent anything?

You need to read some documentation on Legionella bacteria.

"Rod Speed" wrote in message
...
Solar Flare wrote:

In tests of thousands of water heaters 40% were found to contain
lethal doses of legionella bacteria.

Further testing found that none of the water heaters were gas
fired.

Bet that was just because so few of them were gas fired.

Only the electric heated units were the problem below the bottom
element.

Because most codes mandate a minimum thermostat temp.

I believe as long as the water is moving frequently and/
or heated past 96F the legionella is rendered inert.

You're wrong on that last. Needs to be 140F

And there is no 'rendered inert', its either killed or it aint.


"Rod Speed" wrote in message
...
daestrom wrote:
"Robert Gammon" wrote in message
. net...
wrote:
Robert Gammon misunderstands again:
snip
Goto www.gfxtechnology.com/GFX-STAR.html and click on
Application
Notes and click on the link to Retrofit of an existing Solar Hot
Water Heater. You sir, need to READ first, before you make
accusations that you
cannot back up with facts.

In there he describes a patent pending application of GFX Star
in
an
industrial process control application.

The models of what happens to the efficiency of his product with
changing potable water flows thru the equipment are there for
all
to
see.

Okay, *I* read the documents. It is clear that you must have a
separate storage tank for the GFX-star setup to work 'as
advertised'.
Only by using a *cooler* separate storage tank is the setup able
to
capture the waste heat from 'batch' drains. Once the storage
tank
reaches the temperature of the greywater (or exceeds it in the
conventional heater storage tank), performance will drop off.

This way can effectively 'shift' the heat from outgoing batch
drains
to a separate storage tank of fresh-water. So the greywater
doesn't
have to be stored, and you can still use the low-maintenance,
straight-bore, GFX heat-exchanger.

For 'best' performance, you would want to route the storage tank
outlet to the 'cold' tap for the shower as well. This looks like
their 'tempering valve' arrangement. But you might be better off
routing straight 'cold' water from the supply directly to sinks
and
laundry, bypassing the whole setup for cold supply to those usage
points. Otherwise you would be wasting some of the captured heat
on
laundry, and who wants a glass of warm water to drink. Some more
plumbing :-(

Someone mentioned some concerns about storage tank of 'warm'
water
and
Legionarries disease. But if you have treated water, that
probably
isn't too much of a concern.

It is with storage water heaters.

daestrom wrote:

"Robert Gammon" wrote in message
. net...
wrote:
Robert Gammon misunderstands again:
snip
Goto www.gfxtechnology.com/GFX-STAR.html and click on Application
Notes and click on the link to Retrofit of an existing Solar Hot
Water Heater.

You sir, need to READ first, before you make accusations that you
cannot back up with facts.

In there he describes a patent pending application of GFX Star in an
industrial process control application.

The models of what happens to the efficiency of his product with
changing potable water flows thru the equipment are there for all to
see.


Okay, *I* read the documents. It is clear that you must have a
separate storage tank for the GFX-star setup to work 'as advertised'.
Only by using a *cooler* separate storage tank is the setup able to
capture the waste heat from 'batch' drains. Once the storage tank
reaches the temperature of the greywater (or exceeds it in the
conventional heater storage tank), performance will drop off.

Well in the Solar Heater Retrofit, HE DOES NOT USE A SEPARATE TANK!!!

This way can effectively 'shift' the heat from outgoing batch drains
to a separate storage tank of fresh-water. So the greywater doesn't
have to be stored, and you can still use the low-maintenance,
straight-bore, GFX heat-exchanger.

For 'best' performance, you would want to route the storage tank
outlet to the 'cold' tap for the shower as well. This looks like
their 'tempering valve' arrangement. But you might be better off
routing straight 'cold' water from the supply directly to sinks and
laundry, bypassing the whole setup for cold supply to those usage
points. Otherwise you would be wasting some of the captured heat on
laundry, and who wants a glass of warm water to drink. Some more
plumbing :-(

In NEW construction easy to do, or in a home with ALL plumbing in the
basement, this is just a few new runs of 'cold' water. I see the
laundry also getting the warm water from the heat exchanger. Only
refrigerator water supply, and sinks get untreated water. Most all the
clothes washing we do is in Warm water, so if that winds up being a bit
warmer than usual, OK.
Someone mentioned some concerns about storage tank of 'warm' water and
Legionarries disease. But if you have treated water, that probably
isn't too much of a concern.

Its not just Legionnaires, there are an army of bacteria waiting to do
damage. Water with chlorine added, ie city water supplies will be
ok. Well water needs special treatment. My application will be new
construction with a well. All water will be processed thru a Whole
House Filter to get rid of sand and silt. Then it goes thru a
1000gal/day RO with UV to a 350-500 gallon storage tank. A 65psi pump
thn delivers this water to all uses in the house.

Robert Gammon wrote:
daestrom wrote:

"Robert Gammon" wrote in message
. net...
wrote:
Robert Gammon misunderstands again:
snip
snip

For 'best' performance, you would want to route the storage tank
outlet to the 'cold' tap for the shower as well. This looks like
their 'tempering valve' arrangement. But you might be better off
routing straight 'cold' water from the supply directly to sinks and
laundry, bypassing the whole setup for cold supply to those usage
points. Otherwise you would be wasting some of the captured heat on
laundry, and who wants a glass of warm water to drink. Some more
plumbing :-(

Warm water to drink is not good, BUT neither is really cold water
either. Our preference is for cold water, especially in HOT climates.
However we will usually drink MORE water at a time if the water is in
the 60-70F range than in the 40-50F range. The really cold stuff, we
just sip every now and again. A bit warmer and we'll gulp it down.

So in areas that have 40s year round average cold water inlet temp,
treat the WHOLE house to GFX treated water, raising cold water to 65F
helps us drink more water and has no significant affect on cold water
cleaning performance in the laundry.

Note we almost NEVER use the cold cycle in our laundry, so if Warm cycle
water temp changes from 85F to 95F, so what!!!

In alt.solar.thermal Rod Speed wrote:

Thats on the low side of the recommendations,
60C, 140F is much more common.
http://www.google.com.au/search?q=Legionella+60+C


You get more hits for
http://www.google.com.au/search?q=Legionella+50+C

http://www.google.com/search?q=Legionella+50oC
gives a shorter list, and has some interesting links.


http://www.dhmh.state.md.us/html/legionella.htm
says you are just plain wrong using rigorous science.

I see adherence to the earlier advice.

"Legionella die rapidly at 55oC (131o F)(3 log reduction within 1 hour),
and are killed almost immediately at temperatures over 60oC (140oF)."

It was present in the tested systems because they were kept below 43c.

Didn't you say, "Water with chlorine added, ie city water supplies will be
ok. Well water needs special treatment.", earlier?

" As legionella is chlorine tolerant, it will survive many of the standard
municipal water treatment protocols. Once present in a hospital hot water
system, legionella is able to survive and multiply, particularly as hot
water temperatures are kept relatively low to minimize the scald risk for
patients [35]. In Maryland, state regulations for nursing homes limit
temperatures at the outlet to 110oF [43oC](COMAR 10.07.02); "

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

"Robert Gammon" wrote in message
. com...
daestrom wrote:

"Robert Gammon" wrote in message
. net...
wrote:
Robert Gammon misunderstands again:
snip
Goto www.gfxtechnology.com/GFX-STAR.html and click on Application Notes
and click on the link to Retrofit of an existing Solar Hot Water Heater.

You sir, need to READ first, before you make accusations that you cannot
back up with facts.

In there he describes a patent pending application of GFX Star in an
industrial process control application.

The models of what happens to the efficiency of his product with
changing potable water flows thru the equipment are there for all to
see.


Okay, *I* read the documents. It is clear that you must have a separate
storage tank for the GFX-star setup to work 'as advertised'. Only by
using a *cooler* separate storage tank is the setup able to capture the
waste heat from 'batch' drains. Once the storage tank reaches the
temperature of the greywater (or exceeds it in the conventional heater
storage tank), performance will drop off.

Well in the Solar Heater Retrofit, HE DOES NOT USE A SEPARATE TANK!!!


Still seems messed up. The water going into the bottom of the GFX is a
mixture of say 2gpm cold water (flow rate set by the shower head), and 4-5
gpm hot/warm water from the heater bottom (flow set by the pump). In my
book that means the water going into the GFX is *warmer* than the non-pump
setup. And that means the improvement in heat-transfer you get from the
higher flow rate is offset by the higher temperatures in the freshwater
side. Warmer freshwater going in means warmer greywater going down the
drain. And that's a bad thing.

If the circulating pump runs at 4 gpm and the shower at 2 gpm, then it is
crucial to know the tank bottom drain temperature. Using the application
note...
http://www.gfxtechnology.com/GFX-STAR.pdf we see that we can expect the
efficiency to rise from 57% to 67%. But that is based on the Tcold going
into the bottom of the heat-exchanger. So if Tdrain-in is still our same
100F, and the bottom of the tank temperature at the recirc pump suction is a
warm 90F instead of 55F, then

Without pump
57% = (100F - Tdrain-out) / (100F - 55F)
Tdrain-out = 74.4 F
Tfreshwater out = (100 - 74.4)*2gpm / 2gpm + 55 = 80.6
Total energy gained by freshwater (2gpm*8.33 lbm/g)*(80.6-55) = 426.5
Btu/min

Withpump, first find Tcold into hx...
Tcold = (4gpm*90F + 2gpm*55F)/6gpm = 78.3F

Then repeat calculation for 67% efficiency and new Tcold...
67% = (100 - Tdrain-out) / (100 - 78.3)
Tdrain-out = 85.5F
Tfreshwater out = (100 - 85.5)*2gpm/6gpm + 78.3 = 83.13F
Total energy gained by freshwater (6gpm*8.33 lbm/g)*(83.13-78.3) = 241.5
Btu/min

In this situation, leaving the pump off results in a lower CDR (efficiency),
but more energy recovered from the greywater. Isn't life just full of
wondrous things :-)

To get at least the same energy recovery performance with the pump running,
we would need to be sure the coil inlet temperature is at least down to...
0.67 = (100 - 74.4) / (100 - Tcold)
Tcold = 61.8F

And to get that with 2 gpm shower flow and 4 gpm pump flow, the pump suction
from the tank bottom must be at or below...
61.8F = (2*55F + 4*Tbottom) / 6
Tbottom = 65.2 F

But the tank bottom temperature is probably going to be close to the
heat-exchanger's fresh-water outlet temperature (that is after all where the
return water to the tank is coming from). So unless the freshwater exiting
the heat exchanger is no warmer than 65.2F, it's a losing proposition. But
if the freshwater out is that low, then you're losing anyway.

Now, I have no idea what the *real* tank bottom temperature is in this
situation. But if its warmer than 65.2F, then leave the pump off while
showering. Running the pump is still a great way to recover 'batch process'
energy and move it into the freshwater system. And this is still a
significant advantage. Perhaps a timer controlled in the bathroom that
inhibits the pump while someone is in the shower would be the way to go.
Then other 'batch' uses can automatically start the pump on the differential
temperature setup.

Improving 'efficiency' but at the sacrifice of temperature differential
isn't always a winning proposition. Beware of salesmen and their numbers
:-(

daestrom

wrote
Rod Speed wrote

Thats on the low side of the recommendations,
60C, 140F is much more common.
http://www.google.com.au/search?q=Legionella+60+C

You get more hits for
http://www.google.com.au/search?q=Legionella+50+C

You cant just count the hits, you need to consider the source.

http://www.google.com/search?q=Legionella+50oC
gives a shorter list, and has some interesting links.

Nope, none that are useful on that question which
substantiate their claims with rigorous science.

http://www.dhmh.state.md.us/html/legionella.htm
says you are just plain wrong using rigorous science.

I see adherence to the earlier advice.

You need new glasses then.

"Legionella die rapidly at 55oC (131o F)(3 log reduction within 1
hour), and are killed almost immediately at temperatures over 60oC
(140oF)."

Useless for your previous claim about 120F

It was present in the tested systems because they were kept below 43c.

Didn't you say, "Water with chlorine added, ie city water supplies
will be ok. Well water needs special treatment.", earlier?

No, that was someone else.

Chlorine doesnt help much with STORAGE WATER HEATERS.

" As legionella is chlorine tolerant, it will survive many of the
standard municipal water treatment protocols. Once present
in a hospital hot water system, legionella is able to survive and
multiply, particularly as hot water temperatures are kept relatively
low to minimize the scald risk for patients [35]. In Maryland, state
regulations for nursing homes limit temperatures at the outlet to
110oF [43oC](COMAR 10.07.02); "

Again, so much for your 120F claim.

wrote
Rod Speed wrote

Thats on the low side of the recommendations,
60C, 140F is much more common.
http://www.google.com.au/search?q=Legionella+60+C

You get more hits for
http://www.google.com.au/search?q=Legionella+50+C

You cant just count the hits, you need to consider the source.

And most of those hits with 50C are actually saying that
at that temp and below Legionella is a serious problem.

http://www.google.com/search?q=Legionella+50oC
gives a shorter list, and has some interesting links.

Nope, none that are useful on that question which
substantiate their claims with rigorous science.

http://www.dhmh.state.md.us/html/legionella.htm
says you are just plain wrong using rigorous science.

I see adherence to the earlier advice.

You need new glasses then.

"Legionella die rapidly at 55oC (131o F)(3 log reduction within 1
hour), and are killed almost immediately at temperatures over 60oC
(140oF)."

Useless for your previous claim about 120F

It was present in the tested systems because they were kept below 43c.

Didn't you say, "Water with chlorine added, ie city water supplies
will be ok. Well water needs special treatment.", earlier?

No, that was someone else.

Chlorine doesnt help much with STORAGE WATER HEATERS.

" As legionella is chlorine tolerant, it will survive many of the
standard municipal water treatment protocols. Once present
in a hospital hot water system, legionella is able to survive and
multiply, particularly as hot water temperatures are kept relatively
low to minimize the scald risk for patients [35]. In Maryland, state
regulations for nursing homes limit temperatures at the outlet to
110oF [43oC](COMAR 10.07.02); "

Again, so much for your 120F wrote:
In alt.solar.thermal Rod Speed wrote:

Thats on the low side of the recommendations,
60C, 140F is much more common.
http://www.google.com.au/search?q=Legionella+60+C


You get more hits for
http://www.google.com.au/search?q=Legionella+50+C

http://www.google.com/search?q=Legionella+50oC
gives a shorter list, and has some interesting links.


http://www.dhmh.state.md.us/html/legionella.htm
says you are just plain wrong using rigorous science.

I see adherence to the earlier advice.

"Legionella die rapidly at 55oC (131o F)(3 log reduction within 1
hour), and are killed almost immediately at temperatures over 60oC
(140oF)."

It was present in the tested systems because they were kept below 43c.

Didn't you say, "Water with chlorine added, ie city water supplies
will be ok. Well water needs special treatment.", earlier?

" As legionella is chlorine tolerant, it will survive many of the
standard municipal water treatment protocols. Once present in a
hospital hot water system, legionella is able to survive and
multiply, particularly as hot water temperatures are kept relatively
low to minimize the scald risk for patients [35]. In Maryland, state
regulations for nursing homes limit temperatures at the outlet to
110oF [43oC](COMAR 10.07.02); "

Having worked in critical care medicine for over 15yrs, I have yet to
diagnosis or here of a case of Legionaire's disease.


I think you need bad lungs and bad luck exposure to get this illness.
We are more at risk of driving to the corner drug store and dying on
the way...

AstickfortheMULE wrote:

Having worked in critical care medicine for over 15yrs, I have
yet to diagnosis or here of a case of Legionaire's disease.

Irrelevant, the national stats on that are readily available.

I think you need bad lungs and bad luck exposure to get this illness.

You are just plain wrong on that.

We are more at risk of driving to the corner
drug store and dying on the way...

Irrelevant to the question being discussed, WHY MOST CODES REQUIRE
A MINIMUM OF 60C WITH STORAGE HOT WATER SERVICES.

If anything that low incidence is evidence that that
code requirement is observed, by the manufacturers.

Your figures below are very interesting, particularly so for my application.

65F cold water inlet is darn near IMPOSSIBLE here, much less 55F This
thing, Nick's, and Power-Pipe ALL work MUCH better in cold climates than
warm climates.

So the efficiency does drop with rising cold water inlet temps, and Dr V
admits to the same in his notes on the web site. The comparisons of
different regions of North America illustrate that fact.

Hot side out with balanced flow of coil and waste water will have a peak
temp out of near 90F with cold side at 65F per his web notes. I am
likely to have cold water in closer to 70F or even 75F, so the storage
tank and coil temp should rise to near 90F with a long shower and/or
clothes/dish washer in simultaneous operation.

Waste water will only fall to then about 85-90F on exit from the heat
exchanger. that's good for a septic tank as that is what we will be
using. Boiling water 200F or greater going down the drain will kill the
bacteria in the septic tank.

Hot water out of the dishwasher is/is not hotter than incoming hot
water, correct?? Internal heaters raise the temp to above 140F don't they??


daestrom wrote:

"Robert Gammon" wrote in message
. com...
daestrom wrote:

"Robert Gammon" wrote in message
. net...
wrote:
Robert Gammon misunderstands again:
snip
Goto www.gfxtechnology.com/GFX-STAR.html and click on Application
Notes and click on the link to Retrofit of an existing Solar Hot
Water Heater.

You sir, need to READ first, before you make accusations that you
cannot back up with facts.

In there he describes a patent pending application of GFX Star in
an industrial process control application.

The models of what happens to the efficiency of his product with
changing potable water flows thru the equipment are there for all
to see.


Okay, *I* read the documents. It is clear that you must have a
separate storage tank for the GFX-star setup to work 'as
advertised'. Only by using a *cooler* separate storage tank is the
setup able to capture the waste heat from 'batch' drains. Once the
storage tank reaches the temperature of the greywater (or exceeds it
in the conventional heater storage tank), performance will drop off.

Well in the Solar Heater Retrofit, HE DOES NOT USE A SEPARATE TANK!!!


Still seems messed up. The water going into the bottom of the GFX is
a mixture of say 2gpm cold water (flow rate set by the shower head),
and 4-5 gpm hot/warm water from the heater bottom (flow set by the
pump). In my book that means the water going into the GFX is *warmer*
than the non-pump setup. And that means the improvement in
heat-transfer you get from the higher flow rate is offset by the
higher temperatures in the freshwater side. Warmer freshwater going
in means warmer greywater going down the drain. And that's a bad thing.

If the circulating pump runs at 4 gpm and the shower at 2 gpm, then it
is crucial to know the tank bottom drain temperature. Using the
application note...
http://www.gfxtechnology.com/GFX-STAR.pdf we see that we can expect
the efficiency to rise from 57% to 67%. But that is based on the
Tcold going into the bottom of the heat-exchanger. So if Tdrain-in is
still our same 100F, and the bottom of the tank temperature at the
recirc pump suction is a warm 90F instead of 55F, then

Without pump
57% = (100F - Tdrain-out) / (100F - 55F)
Tdrain-out = 74.4 F
Tfreshwater out = (100 - 74.4)*2gpm / 2gpm + 55 = 80.6
Total energy gained by freshwater (2gpm*8.33 lbm/g)*(80.6-55) = 426.5
Btu/min

Withpump, first find Tcold into hx...
Tcold = (4gpm*90F + 2gpm*55F)/6gpm = 78.3F

Then repeat calculation for 67% efficiency and new Tcold...
67% = (100 - Tdrain-out) / (100 - 78.3)
Tdrain-out = 85.5F
Tfreshwater out = (100 - 85.5)*2gpm/6gpm + 78.3 = 83.13F
Total energy gained by freshwater (6gpm*8.33 lbm/g)*(83.13-78.3) =
241.5 Btu/min

In this situation, leaving the pump off results in a lower CDR
(efficiency), but more energy recovered from the greywater. Isn't
life just full of wondrous things :-)

To get at least the same energy recovery performance with the pump
running, we would need to be sure the coil inlet temperature is at
least down to...
0.67 = (100 - 74.4) / (100 - Tcold)
Tcold = 61.8F

And to get that with 2 gpm shower flow and 4 gpm pump flow, the pump
suction from the tank bottom must be at or below...
61.8F = (2*55F + 4*Tbottom) / 6
Tbottom = 65.2 F

But the tank bottom temperature is probably going to be close to the
heat-exchanger's fresh-water outlet temperature (that is after all
where the return water to the tank is coming from). So unless the
freshwater exiting the heat exchanger is no warmer than 65.2F, it's a
losing proposition. But if the freshwater out is that low, then
you're losing anyway.

Now, I have no idea what the *real* tank bottom temperature is in this
situation. But if its warmer than 65.2F, then leave the pump off
while showering. Running the pump is still a great way to recover
'batch process' energy and move it into the freshwater system. And
this is still a significant advantage. Perhaps a timer controlled in
the bathroom that inhibits the pump while someone is in the shower
would be the way to go. Then other 'batch' uses can automatically
start the pump on the differential temperature setup.

Improving 'efficiency' but at the sacrifice of temperature
differential isn't always a winning proposition. Beware of salesmen
and their numbers :-(

daestrom

In alt.solar.thermal Rod Speed wrote:
wrote

You cant just count the hits, you need to consider the source.

So, I continued, narrowing the chase.

http://www.google.com/search?q=Legionella+50oC
gives a shorter list, and has some interesting links.

Nope, none that are useful on that question which
substantiate their claims with rigorous science.

None that agree with you, I take it?

http://www.dhmh.state.md.us/html/legionella.htm
says you are just plain wrong using rigorous science.

I see adherence to the earlier advice.

You need new glasses then.

"Legionella die rapidly at 55oC (131o F)(3 log reduction within 1
hour), and are killed almost immediately at temperatures over 60oC
(140oF)."

Useless for your previous claim about 120F

In a continuum, or can you not hold a thought that long?
immediately at 60, 1 hour at 55, 2 hours at 50, not mentioned in this
quote, but wait, continue further if you can.

It was present in the tested systems because they were kept below 43c.

in a hospital hot water system, legionella is able to survive and
multiply, particularly as hot water temperatures are kept relatively
low to minimize the scald risk for patients [35]. In Maryland, state
regulations for nursing homes limit temperatures at the outlet to
110oF [43oC](COMAR 10.07.02); "

Again, so much for your 120F claim.

The tested samples had Legionella because they were kept below 110f. How
does that say anything about my 120f claim?

You live somewhere that has a code that requires hotter water.
I find attributions for lower temperatures, but no code requirement.

So, let me look in three places that I care about as references:
nih.gov and CDC.gov as research points, and ca.gov, because they regulate
my life.

Referring to cooling towers, not DWH:
http://www.energy.ca.gov/2005publica...0-2005-025.PDF
"Keep cold water below 25 C (77 F) and hot water above 55 C (131 F)."

From the Centers for Disease Control, whom I would consider to be the
foremost authority.
http://iier.isciii.es/mmwr/preview/m...l/rr5210a2.htm
"The bacteria are rarely found in municipal water supplies and tend to
colonize plumbing systems and point-of-use devices. To colonize,
legionellae usually require a temperature range of 77F--108F (25C--42.2C )
and are most commonly located in hot water systems. "

http://www.cdc.gov/ncidod/EID/vol12no04/05-1101.htm
"Legionella colonized 60% of the hot water systems before monochloramine
.... Increased prevalence of Legionella colonization was associated with
water heater temperatures 50C ...grows optimally at 35C and multiplies
between 25C and 42C"

Chloramine, not chlorine, is used in public water systems in California.

Further down on the CDC page is a recommendation for health care facilities
to use a system as you described, 61c water storage, and blending to no
more than 51 for delivery.

http://www.awt.org/Legionella03.pdf
seems to be an easy to read correlation of data from sources that I would
consider valuable. Page 12 speaks of DWH.

Pages that I've lost reference to refer to the desire for hotter
temperatures for Legionella protection, mitigated by the more pressing need
to prevent scalding.


I'm done now. You win.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

wrote
Rod Speed wrote
wrote
Rod Speed wrote

Thats on the low side of the recommendations,
60C, 140F is much more common.
http://www.google.com.au/search?q=Legionella+60+C

You get more hits for
http://www.google.com.au/search?q=Legionella+50+C

You cant just count the hits, you need to consider the source.

And you ****ed that up completely anyway, given that
the vast bulk of the 50C hits said that that temp is
what sees a significant problem with Legionella.

So, I continued, narrowing the chase.

No you didnt, that has the same problem, the
vast bulk of the 50C hits said that that temp is
what sees a significant problem with Legionella.

http://www.google.com/search?q=Legionella+50oC
gives a shorter list, and has some interesting links.

Nope, none that are useful on that question which
substantiate their claims with rigorous science.

None that agree with you, I take it?

Even you should be able to bull**** your way out of your
predicament better than that pathetic effort. Not one of those
recommends the use of 120F with water storage heaters.

http://www.dhmh.state.md.us/html/legionella.htm
says you are just plain wrong using rigorous science.

I see adherence to the earlier advice.

You need new glasses then.

"Legionella die rapidly at 55oC (131o F)(3 log reduction
within 1 hour), and are killed almost immediately at
temperatures over 60oC (140oF)."

Useless for your previous claim about 120F

In a continuum, or can you not hold a thought that long?

Even you should be able to bull**** your way out
of your predicament better than that pathetic effort.

immediately at 60, 1 hour at 55, 2 hours at 50,

Pity that none recommend the use of your original stupid
pig ignorant claim about 120F with storage water heaters.

not mentioned in this quote, but wait, continue further if you can.

Even you should be able to bull**** your way out
of your predicament better than that pathetic effort.

It was present in the tested systems
because they were kept below 43c.

in a hospital hot water system, legionella is able to survive and
multiply, particularly as hot water temperatures are kept relatively
low to minimize the scald risk for patients [35]. In Maryland, state
regulations for nursing homes limit temperatures at the outlet to
110oF [43oC](COMAR 10.07.02); "

Again, so much for your 120F claim.

The tested samples had Legionella because they were kept
below 110f. How does that say anything about my 120f claim?

Even someone as stupid as you should have noticed that
there isnt much difference between those two, and that the
vast bulk if not all of those hits with 50C used that as the
temperature at which legionella continues to breed, stupid.

You live somewhere that has a code that requires hotter water.

So do you very likely.

I find attributions for lower temperatures, but no code requirement.

Your problem.

So, let me look in three places that I care about
as references: nih.gov and CDC.gov as research
points, and ca.gov, because they regulate my life.

Referring to cooling towers, not DWH:

So completely irrelevant to what is being discussed, storage hot water
systems.

http://www.energy.ca.gov/2005publica...0-2005-025.PDF
"Keep cold water below 25 C (77 F) and hot water above 55 C (131 F)."

From the Centers for Disease Control, whom
I would consider to be the foremost authority.
http://iier.isciii.es/mmwr/preview/m...l/rr5210a2.htm
"The bacteria are rarely found in municipal water supplies and tend
to colonize plumbing systems and point-of-use devices. To colonize,
legionellae usually require a temperature range of 77F--108F
(25C--42.2C ) and are most commonly located in hot water systems. "

Pity about the rigorous scientific evidence cited above and in
countless other hits even you should be able to find using google.

http://www.cdc.gov/ncidod/EID/vol12no04/05-1101.htm
"Legionella colonized 60% of the hot water systems before
monochloramine ... Increased prevalence of Legionella colonization
was associated with water heater temperatures 50C ...

So much for your stupid claim about 120F

grows optimally at 35C and multiplies between 25C and 42C"

Chloramine, not chlorine, is used in public water systems in California.

Irrelevant.

Further down on the CDC page is a recommendation for health
care facilities to use a system as you described, 61c water storage,

And there might just be a reason for that recommendation, stupid.

and blending to no more than 51 for delivery.

Irrelevant to what is being discussed.

http://www.awt.org/Legionella03.pdf
seems to be an easy to read correlation of data from sources
that I would consider valuable. Page 12 speaks of DWH.

Pages that I've lost reference to refer to the desire
for hotter temperatures for Legionella protection,
mitigated by the more pressing need to prevent scalding.

There are other ways to avoid scalding while
continuing with 60C for the water storage temp.

I'm done now. You win.

I do indeed, you never could bull**** your way out of a wet paper bag.

In alt.solar.thermal Rod Speed wrote:
wrote

The tested samples had Legionella because they were kept
below 110f. How does that say anything about my 120f claim?

Even someone as stupid as you should have noticed that
there isnt much difference between those two, and that the

Not much difference between 110F and 120F?

was associated with water heater temperatures 50C ...

So much for your stupid claim about 120F

But a lot of difference between 120F and 50C ?

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

wrote
Rod Speed wrote
wrote

in a hospital hot water system, legionella is able to survive and
multiply, particularly as hot water temperatures are kept relatively
low to minimize the scald risk for patients [35]. In Maryland, state
regulations for nursing homes limit temperatures at the outlet to
110oF [43oC](COMAR 10.07.02); "

Again, so much for your 120F claim.

The tested samples had Legionella because they were kept
below 110f. How does that say anything about my 120f claim?

Even someone as stupid as you should have noticed
that there isnt much difference between those two,

Not much difference between 110F and 120F?

Not as far as what is being discussed, legionella breeding, stupid.

and that the vast bulk if not all of those hits with 50C used that as
the temperature at which legionella continues to breed, stupid.

So much for your stupid claim about 120F

But a lot of difference between 120F and 50C ?

Never ever could bull**** its way out of a wet paper bag.

"Robert Gammon" wrote in message
. com...
Your figures below are very interesting, particularly so for my
application.

65F cold water inlet is darn near IMPOSSIBLE here, much less 55F This
thing, Nick's, and Power-Pipe ALL work MUCH better in cold climates than
warm climates.

So the efficiency does drop with rising cold water inlet temps, and Dr V
admits to the same in his notes on the web site. The comparisons of
different regions of North America illustrate that fact.
Hot side out with balanced flow of coil and waste water will have a peak
temp out of near 90F with cold side at 65F per his web notes. I am
likely to have cold water in closer to 70F or even 75F, so the storage
tank and coil temp should rise to near 90F with a long shower and/or
clothes/dish washer in simultaneous operation.

Waste water will only fall to then about 85-90F on exit from the heat
exchanger. that's good for a septic tank as that is what we will be
using. Boiling water 200F or greater going down the drain will kill the
bacteria in the septic tank.
Hot water out of the dishwasher is/is not hotter than incoming hot water,
correct?? Internal heaters raise the temp to above 140F don't they??


I think that's an individual washer issue. Many do have internal heaters to
heat water up to 140F. I've seen a couple that recommend 120F hot-water
feed, then boost it internally to 140F. But those with an internal heater
often have various cycles and one is an 'energy saver' mode that inhibits
the water-heater. But remember, plain GFX won't recover any of that. Only
a GFX-star or Nick's system would recover energy from a 'batch' process like
a dishwasher that fills and drains at different times.

For your climate, with very warm inlet water temperatures, it's a
double-edged sword. Yes, it makes these sorts of heat-exchangers less
efficient overall, and they recover less energy from the greywater. But on
the other side, it takes less energy to heat the water in the first place
from 70F to 120F than it would from 55F to 120F (in the winter where I'm
at, cold water inlet runs about 35F-38F).

So the economics of such a system for you is probably not as attractive as
it is for one of us in the 'great white north' ;-) After all, a 2gpm shower
where I am in the winter, without a heat-exchanger, the greywater is
carrying away energy at....

2gpm*8.33 lbm/g * (100-35) = 1083 Btu/minute

For you, it would run more like....

2gpm*8.33 lbm/g * (100-70) = 500 Btu/minute

So my GFX heat-exchanger running at just 50% recovers about 541 Btu/min and
can pay for itself in avoided energy costs in under three years. Your's,
even if it runs at 67% can only recover 334 Btu/min. If it cools greywater
outlet to 87F, that means greywater is now carrying away...

2gpm*8.33 lbm/g *(100-87) = 217 Btu/minute

And you'd be recovering (500-217) = 283 Btu/minute. Makes the payback
analysis a lot worse for your situation than in mine.

But on the other hand, you need less energy without any sort of hx for that
shower than the energy I need even *with* a GFX heat-exchanger.

daestrom

wrote:
In alt.solar.thermal Rod Speed wrote:
wrote

But a lot of difference between 120F and 50C ?

Never ever could bull**** its way out of a wet paper bag.

How much difference is there between 120F and 50C?

Never ever could bull**** its way out of a wet paper bag.

daestrom wrote:

For your climate, with very warm inlet water temperatures, it's a
double-edged sword. Yes, it makes these sorts of heat-exchangers less
efficient overall, and they recover less energy from the greywater.

Dr. V says the (Canadian) NRC tested the GFX during the summer and
the Power Pipe during the winter without correcting for the water
temperature difference, which made the Power Pipe look better.

And FSEC biased their tests by evaluating the GFX as an alternative vs
a helpful addition to solar water heating, and didn't test it with
water heating panels that were reoriented for more winter sun,
which would have improved the results.

And the GFX still doesn't have an US Energy Star rating. Then again,
neither do water heaters nor clothes dryers.

There seems to be a lot of jiggery-pokery here.

Nick

daestrom wrote:

"Robert Gammon" wrote in message
. com...
Your figures below are very interesting, particularly so for my
application.

65F cold water inlet is darn near IMPOSSIBLE here, much less 55F This
thing, Nick's, and Power-Pipe ALL work MUCH better in cold climates
than warm climates.

So the efficiency does drop with rising cold water inlet temps, and
Dr V admits to the same in his notes on the web site. The
comparisons of different regions of North America illustrate that fact.
Hot side out with balanced flow of coil and waste water will have a
peak temp out of near 90F with cold side at 65F per his web notes.
I am likely to have cold water in closer to 70F or even 75F, so the
storage tank and coil temp should rise to near 90F with a long shower
and/or clothes/dish washer in simultaneous operation.

Waste water will only fall to then about 85-90F on exit from the heat
exchanger. that's good for a septic tank as that is what we will be
using. Boiling water 200F or greater going down the drain will kill
the bacteria in the septic tank.
Hot water out of the dishwasher is/is not hotter than incoming hot
water, correct?? Internal heaters raise the temp to above 140F don't
they??


I think that's an individual washer issue. Many do have internal
heaters to heat water up to 140F. I've seen a couple that recommend
120F hot-water feed, then boost it internally to 140F. But those with
an internal heater often have various cycles and one is an 'energy
saver' mode that inhibits the water-heater. But remember, plain GFX
won't recover any of that. Only a GFX-star or Nick's system would
recover energy from a 'batch' process like a dishwasher that fills and
drains at different times.

For your climate, with very warm inlet water temperatures, it's a
double-edged sword. Yes, it makes these sorts of heat-exchangers less
efficient overall, and they recover less energy from the greywater.
But on the other side, it takes less energy to heat the water in the
first place from 70F to 120F than it would from 55F to 120F (in the
winter where I'm at, cold water inlet runs about 35F-38F).

So the economics of such a system for you is probably not as
attractive as it is for one of us in the 'great white north' ;-)
After all, a 2gpm shower where I am in the winter, without a
heat-exchanger, the greywater is carrying away energy at....

2gpm*8.33 lbm/g * (100-35) = 1083 Btu/minute

For you, it would run more like....

2gpm*8.33 lbm/g * (100-70) = 500 Btu/minute

So my GFX heat-exchanger running at just 50% recovers about 541
Btu/min and can pay for itself in avoided energy costs in under three
years. Your's, even if it runs at 67% can only recover 334 Btu/min.
If it cools greywater outlet to 87F, that means greywater is now
carrying away...

2gpm*8.33 lbm/g *(100-87) = 217 Btu/minute

And you'd be recovering (500-217) = 283 Btu/minute. Makes the payback
analysis a lot worse for your situation than in mine.

But on the other hand, you need less energy without any sort of hx for
that shower than the energy I need even *with* a GFX heat-exchanger.

All true, in the Sunbelt (I'm on the fringes as we are wet and hot,
whereas the main body is dry and hot), the energy recovered from a GFX,
GFX Star, Nick's, or PowerPipe is much lower than will be seen in cooler
climates. Still, if we raise inlet water temps to the hot water heater
to about 90F, getting to 140F from 90F is EASY compared to getting from
50F or 40F to 140F First hour ratings and recovery times are all about
raising water temp 90F above incoming cold temp With only a 50F
increase in feed water temp to meet the 140F spec, tank less, LP, NG, or
electric will spend comparatively little energy maintaining the tank
regardless of application.

Yes, to recover dish/clothes washer heat, we need a pump in the loop and
we may also need a storage tank. The issue with the storage tank is
legionella. However, whenever water warmer than the water in the coils
goes down thru the heat exchanger, whether that is shower drain, sink
drain, toilet flush, dishwasher, clotheswasher, the pump turns on and
circulates warm water thru the storage tank/coils and does so at a
relatively high rate (10-15gph).

With any hot water demand, the cold supply from city/well flows thru the
coils and into the storage tank. So filling a bath runs 70-75F water
into the bottom of the coils, and about 90F out at the top. Draining
the bath, starting a shower, emptying a hot clothes wash cycle, emptying
the dish washer will start the pump, and we get a blended mix of fresh
(70-75F) and storage water (85-90F). What is the ratio?? If it is
50:50, then water enters the coils at about 80F and exits the top at
near 90F.

And yes the payback period is 6-8 years for me. However, the payback
could be MUCH shorter, depending on what energy prices do over the next
decade. Are we going to see gas prices under $2.00/gal, will
electricity prices go back under $0.10 KWH, will Propane prices go back
under $1.00........... If the trend of the last few years continues,
the payback period even for me, could be 3-4 years.

And one of my goals with this is to take the risk out of sink use. We
sometimes, not often, but sometimes pour boiling water (200F+) down the
drain (i.e. pasta, boiled corn....) That is verboten for a septic
tank. Having a GFX Star in place protects the septic tank as the grey
water will exit the heat exchanger well below the dangerous temps for
the bacteria in the septic tank. i.e.greywater temp, we HOPE will drip
below 125 on this trip thru the heat exchanger.

That's a question for you/ Dr V. Model 200F greywater inlet temp, 70F
cold water inlet to heat exchanger, what is the exiting greywater temp?

Robert Gammon wrote:

... We sometimes, not often, but sometimes pour boiling water (200F+) down
the drain (i.e. pasta, boiled corn....) That is verboten for a septic tank.

Wrong again.

Nick

wrote:
Robert Gammon wrote:


... We sometimes, not often, but sometimes pour boiling water (200F+) down
the drain (i.e. pasta, boiled corn....) That is verboten for a septic tank.


Wrong again.

Nick


Nick,


Ok, I stand corrected.

Some long term users of septic tanks were told LONG ago NOT to pour
boiling water down the drain, it hurts the bacteria in the tank.

While this is true, it is unlikely in the extreme that you could put
enough boiling water down the drain to raise 1000 gallons of waste in
the septic tank by more than a degree or two.

Robert Gammon errs again:

... We sometimes, not often, but sometimes pour boiling water (200F+) down
the drain (i.e. pasta, boiled corn...) That is verboten for a septic tank.

Wrong again.

Ok, I stand corrected.

Some long term users of septic tanks were told LONG ago NOT to pour
boiling water down the drain, it hurts the bacteria in the tank.

While this is true, it is unlikely in the extreme that you could put
enough boiling water down the drain to raise 1000 gallons of waste in
the septic tank by more than a degree or two.

If your 1000 gallon tank were 60 F and perfectly insulated inside
the concrete and you added a gallon of 200 F water, the new temp
would be (200x1+999x60)/1000 = 60.14 F. And bacteria love heat.
Every time you raised tank temp by 10 F (if you could do that),
the digestion rate would double, up to about 130 F.

How can you be so wrong so often? :-)

Nick

"Robert Gammon" wrote in message
om...
daestrom wrote:

snip
But on the other hand, you need less energy without any sort of hx for
that shower than the energy I need even *with* a GFX heat-exchanger.

All true, in the Sunbelt (I'm on the fringes as we are wet and hot,
whereas the main body is dry and hot), the energy recovered from a GFX,
GFX Star, Nick's, or PowerPipe is much lower than will be seen in cooler
climates. Still, if we raise inlet water temps to the hot water heater to
about 90F, getting to 140F from 90F is EASY compared to getting from 50F
or 40F to 140F First hour ratings and recovery times are all about
raising water temp 90F above incoming cold temp With only a 50F increase
in feed water temp to meet the 140F spec, tank less, LP, NG, or electric
will spend comparatively little energy maintaining the tank regardless of
application.

Yes, to recover dish/clothes washer heat, we need a pump in the loop and
we may also need a storage tank. The issue with the storage tank is
legionella. However, whenever water warmer than the water in the coils
goes down thru the heat exchanger, whether that is shower drain, sink
drain, toilet flush, dishwasher, clotheswasher, the pump turns on and
circulates warm water thru the storage tank/coils and does so at a
relatively high rate (10-15gph).

Careful, in the control you need to consider if the greywater inlet
temperature is lower than the tank temperature. Just looking at coil
temperature could result in some adverse operation. Maybe not in your
specific circumstance, but in some common situations. For example, for me
in the winter, the coil (located in the basement) is cooler than the living
space. So flushing the toilet with 70F water from its tank, while the coil
is 55F, would start the pump and circulate 140F water from the tank to the
coil. And that would actually end up *heating* the greywater.

So the controls may need to be a bit 'smarter' and also consider the
hot-water tank's drain temperature. Just so you don't start the pump when
the tank bottom drain is warmer than the greywater.


With any hot water demand, the cold supply from city/well flows thru the
coils and into the storage tank. So filling a bath runs 70-75F water into
the bottom of the coils, and about 90F out at the top. Draining the bath,
starting a shower, emptying a hot clothes wash cycle, emptying the dish
washer will start the pump, and we get a blended mix of fresh (70-75F) and
storage water (85-90F). What is the ratio?? If it is 50:50, then water
enters the coils at about 80F and exits the top at near 90F.

And yes the payback period is 6-8 years for me. However, the payback
could be MUCH shorter, depending on what energy prices do over the next
decade. Are we going to see gas prices under $2.00/gal, will
electricity prices go back under $0.10 KWH, will Propane prices go back
under $1.00........... If the trend of the last few years continues, the
payback period even for me, could be 3-4 years.


Well this is certainly true. Energy prices certainly seem to be rising
faster than general inflation, and that means payback on energy conserving
devices of all sorts have better payback.

And one of my goals with this is to take the risk out of sink use. We
sometimes, not often, but sometimes pour boiling water (200F+) down the
drain (i.e. pasta, boiled corn....) That is verboten for a septic tank.
Having a GFX Star in place protects the septic tank as the grey water will
exit the heat exchanger well below the dangerous temps for the bacteria in
the septic tank. i.e.greywater temp, we HOPE will drip below 125 on this
trip thru the heat exchanger.

That's a question for you/ Dr V. Model 200F greywater inlet temp, 70F
cold water inlet to heat exchanger, what is the exiting greywater temp?

If we go with the GFX-star setup, and assume we are not drawing off any
water (hot or cold) while dumping this boiling hot water down the drain, we
could *assume* the pump start will circulate about 4 gpm. But how fast does
the water flow when you dump a large pot of pasta through a collander into
the sink drain?

This is the sort of question we could spend quite a long time trying to
figure out. After all, the sink drain is probably a 1 1/2 pipe, that leads
some distance to the main drain. There is perhaps 1 lbm of cold water
sitting in the P-trap under the sink. Your home may have a 'master trap'
that contains another 4 lbm or so of water. Your sink could be metal. The
piping from the house to the tank are probably 70F (same general ground
temperature as your water supply). The factors are many and various.

But looking at the GFX alone, a G4-60 model has about 110 turns of 1/2" Cu
pipe with a mean turn diameter of 4 1/2 inches. That holds about 11 lbm of
freshwater. And the whole thing weighs in at 40 lbm of Cu when dry. So I
don't think you have much to worry about. Take a *large* pot of boiling
water holding 2 1/2 gallons (20.8 lbm) of 212F water. Mix that with 1 lbm
P-trap water at 70F, and 11 lbm of 70F water in the GFX, and 40 lbm of Cu
(equivalent capacitance as 40 lbm *(0.90 / 1.00) = 36 lbm) at 70F and you
get a mixture at...

(11lbm*70F + 1lbm*70F + 36lbm*70F + 20.8lbm*212F) / (11lbm + 1lbm + 36lbm +
20.8lbm) = 112.9F

Now, the 'pasta water' isn't in contact with the GFX long enough to reach
equilibrium with it, but it will lose a lot of its energy just flowing
through a GFX style heat-exchanger. Combine this with the other factors I
mentioned, and I don't think your septic tank will receive any water over
120F. And considering the volume of a septic tank versus the 2 1/2 gallons
of 'no-longer-boiling-hot' water, I wouldn't be concerned unless you making
pasta for an army and dumping pots of water down the drain every ten
minutes.

daestrom

wrote:
Robert Gammon errs again:


... We sometimes, not often, but sometimes pour boiling water (200F+) down
the drain (i.e. pasta, boiled corn...) That is verboten for a septic tank.

Wrong again.

Ok, I stand corrected.

Some long term users of septic tanks were told LONG ago NOT to pour
boiling water down the drain, it hurts the bacteria in the tank.

While this is true, it is unlikely in the extreme that you could put
enough boiling water down the drain to raise 1000 gallons of waste in
the septic tank by more than a degree or two.


If your 1000 gallon tank were 60 F and perfectly insulated inside
the concrete and you added a gallon of 200 F water, the new temp
would be (200x1+999x60)/1000 = 60.14 F. And bacteria love heat.
Every time you raised tank temp by 10 F (if you could do that),
the digestion rate would double, up to about 130 F.

How can you be so wrong so often? :-)

Nick


Well ground temps are around 70-75 so getting towards 80 and some of
them die off.

I will aim for a larger than 1000 gal tank just to be sure. And a
larger than normal drain field as this will be a 2.5 acre lot.