tankless water heaters in cold climate
 

I was wondering if anyone in a cold climate (Canada or likewise) has
used the tankless heaters. I was thinking of getting two to replace
an old hot water heater but want to be sure this will get the water
hot enough. The cold water temp from the tap here is 42F.

You've got the right idea of maybe using more than one. See Takagi-usa.com.
They have support in Canada. I'm happy with one that I installed.

Dave


In article ,
lid (cthorne111) wrote:

I was wondering if anyone in a cold climate (Canada or likewise) has
used the tankless heaters. I was thinking of getting two to replace
an old hot water heater but want to be sure this will get the water
hot enough. The cold water temp from the tap here is 42F.

"cthorne111" wrote in message
news:caa6$4248936f$455da0d2$2072@allthenewsgroups. com...
I was wondering if anyone in a cold climate (Canada or likewise) has
used the tankless heaters. I was thinking of getting two to replace
an old hot water heater but want to be sure this will get the water
hot enough. The cold water temp from the tap here is 42F.


This is Turtle.

I called Glen Johnson who works at the warehouse at his house and ask him about
supply water temp. verses the out put temp. of the water about the Rinnai
Continuum type tankless hot water heater. He said at any temp water supply from
33ºF water the unit will supply 96ºF to 140ºF water all day long at 8.5 GPM.
Over the 140ºF may be a problem but just cut back to 2 shower at one time and go
back to 180ºF water out put .

Now just a not here. 140ºF water will blister a human or burn the hide off you.
also 180ºF water will kill most humans.

TURTLE

"TURTLE" wrote in message
. ..

"cthorne111" wrote in message
news:caa6$4248936f$455da0d2$2072@allthenewsgroups. com...
I was wondering if anyone in a cold climate (Canada or likewise) has
used the tankless heaters. I was thinking of getting two to replace
an old hot water heater but want to be sure this will get the water
hot enough. The cold water temp from the tap here is 42F.


This is Turtle.

I called Glen Johnson who works at the warehouse at his house and ask him
about supply water temp. verses the out put temp. of the water about the
Rinnai Continuum type tankless hot water heater. He said at any temp water
supply from 33ºF water the unit will supply 96ºF to 140ºF water all day
long at 8.5 GPM. Over the 140ºF may be a problem but just cut back to 2
shower at one time and go back to 180ºF water out put .

Now just a not here. 140ºF water will blister a human or burn the hide off
you. also 180ºF water will kill most humans.

TURTLE


What does it do to Turtles?

"Oscar_Lives" wrote in message
news:Sa42e.11957$NW5.10475@attbi_s02...

"TURTLE" wrote in message
. ..

"cthorne111" wrote in message
news:caa6$4248936f$455da0d2$2072@allthenewsgroups. com...
I was wondering if anyone in a cold climate (Canada or likewise) has
used the tankless heaters. I was thinking of getting two to replace
an old hot water heater but want to be sure this will get the water
hot enough. The cold water temp from the tap here is 42F.


This is Turtle.

I called Glen Johnson who works at the warehouse at his house and ask him
about supply water temp. verses the out put temp. of the water about the
Rinnai Continuum type tankless hot water heater. He said at any temp water
supply from 33ºF water the unit will supply 96ºF to 140ºF water all day long
at 8.5 GPM. Over the 140ºF may be a problem but just cut back to 2 shower at
one time and go back to 180ºF water out put .

Now just a not here. 140ºF water will blister a human or burn the hide off
you. also 180ºF water will kill most humans.

TURTLE


What does it do to Turtles?

This is turtle.

That is what the shell is for to not let it burn them.

TURTLE

TURTLE writes:

He said at any temp water supply from
33§F water the unit will supply 96§F to 140§F water all day long at
8.5 GPM.

Bunk.

32 deg F rising to 96 or 140, that's 64 to 108 BTUs per pound, or 534 to
901 BTUs per gallon, or 4540 to 7660 BTUs per minute at 8.5 gpm, or 272K to
460K BTUs/hr, assuming 100 percent efficiency, which equates to 80 to 135
kilowatts, or 333 to 563 amps of 240 VAC.

Does this unit come with a hookup to Niagara Falls, or perhaps the Alaskan
pipeline?

32 deg F rising to 96 or 140, that's 64 to 108 BTUs per pound, or 534 to
901 BTUs per gallon, or 4540 to 7660 BTUs per minute at 8.5 gpm, or 272K to
460K BTUs/hr, assuming 100 percent efficiency, which equates to 80 to 135
kilowatts, or 333 to 563 amps of 240 VAC.

Does this unit come with a hookup to Niagara Falls, or perhaps the Alaskan
pipeline?

See below for a more practical example and accurate calculation.

Who uses 8.5 gpm? Shower restricter inserts in the USA are
restricted to a maximum flow of 2.5 GPM.

Incoming water is at 42F not 32F, so a rise from 42F to 96F (a good
hot shower) is 54 BTU per pound.

If one gallon of water weighs 8.33 lbs, that means a one minute shower
uses 20.82 lbs of water requiring a rise of 54 BTU or 1124 BTU's per
minute. This x60 is 67440 BTU/hour.

One kiloWatt is 3412 BTU so:

A one hour shower would consume 19.77 kwh
A one minute shower would consume 0.33 kwh

And a realistic 10 minute shower would consume about 3.33 kwh

For the instantaneous power load, a one hour 2.5 gpm shower with a 54F
rise consumes 19.77 kwh, which at 240 volts = 82 amps whether you use
the shower for 1 minute or 60 minutes.

82 amps is still pretty high, but it is nowhere near 333 amps of 240
VAC as erronously stated above.

Few residential pass through DHW heatingunits will be rated at 80 amps
but 40 amp 240V units are quite common. In fact, if you are going to
go with two electrical units like this, the manufactuer recommends
putting the plumbing in series.

Only problem is if every time you turn on the shower your neighbors'
lights dim (because of the 80 amp demand draw, your neighbors and the
power company may give you a hard time.

Beachcomber

I have a small Bosch 117000 btu and my water has been at 33f- 34f
incomming at -17f. Even at 33-34 incomming I never have to have the
Bosch on high to take a warm shower or it would be to hot. A 180000 btu
Rinnai will do maybe 3 water reduced showers at 34f incomming no
problem, and definatly 2.

An Electric would need 120A for 1 shower.

Why 2 tankless, One sized properly can handle alot of load. Rinnai is
the most efficient tankless unit I know of. Rinnai also has built in
freeze protection to -30f.

I assume you want gas tankless

"I was wondering if anyone in a cold climate (Canada or likewise) has
used the tankless heaters. I was thinking of getting two to replace
an old hot water heater but want to be sure this will get the water
hot enough. The cold water temp from the tap here is 42F. "


RTFM This is one of the most basic things that is specd.

Gas is not available here, electric is the only option. I couldn't
find an electric that would seem to do the job with only one unit.
Plus from what I know there is a limit of 60 amps for any one
breaker. So one 80 amp would be out of the question. I was just
wondering if anyone has the double electric design and if it works
well with cold incoming water temps.

No propane?, Put 2 60a together you get 120a

You must have cheap subsides Hydro to only want electric. What is your
kwh cost. There are alot of electric units avalaible, they are cheaper
than gas and perform well if sized right. For one use shower look at
Bosch for starters, probably at you local big box. If electric is that
cheap there then you will find localy what works and what is crap. I pay
125kwh, you must pay near .04 to be competitive to gas.

On Tue, 29 Mar 2005 14:13:14 +0000,
lid (cthorne111) wrote:

Gas is not available here, electric is the only option. I couldn't
find an electric that would seem to do the job with only one unit.
Plus from what I know there is a limit of 60 amps for any one
breaker. So one 80 amp would be out of the question. I was just
wondering if anyone has the double electric design and if it works
well with cold incoming water temps.


Don't forget to figure your operating costs. Let's say you have two
10 kWh units plumbed with the water line in series or 20 kWh total.

Let's estimate that a 10 minute shower will use 1/6 of the 20 kWh or
3.34 kWh per 10 minute shower.

If you are fortunate to live in say... Washington State, then you
might be paying 8 cents per kWh , in which case that 10 minute shower
would cost you $0.27 for that 10 minute shower.

In a high utility expense place like Vermont, electricity is something
like $0.14 per hour, so your 10 minute shower would cost you $0.47

Hopefully the utility company won't charge you a demand charge for
that 20 kWh that

Beachcomber

I would feel better knowing of people who have done this before
investing a lot of money in something that may work according to the
manual only.

Beachcomber writes:

82 amps is still pretty high, but it is nowhere near 333 amps of 240
VAC as erronously stated above.

My calculations derived from the absurd claim that the unit would deliver
8.5 gpm "all day long" with a 64 to 108 deg F rise in temp. The error is
yours in your cavalier dismissal of "who uses 8.5 gpm". Whether anyone
does or not, that was THE CLAIM.