Water Heater Energy Use, How calculated?
 

My electric water heater has a sticker that says it uses
4720 KWH/year.
How is that number calculated?

I assume there's a standard somewhere with assumed temperature
for input water and air ambient and some number of gallons heated.???

I can calculate the energy needed to heat the water I use.
I need a way to estimate the energy radiated from the
tank. I'm way to lazy to try to measure it.
Thanks, mike

Water Heater Energy Use, How calculated?
 

mike wrote:
My electric water heater has a sticker that says it uses
4720 KWH/year.
How is that number calculated?

I assume there's a standard somewhere with assumed temperature
for input water and air ambient and some number of gallons heated.???
....

EPA/DOE Energy Star tests -- they're not worth much for anything other
than relative rankings.

--

Water Heater Energy Use, How calculated?
 

On Apr 12, 2:12�pm, mike wrote:
My electric water heater has a sticker that says it uses
4720 KWH/year.
How is that number calculated?

I assume there's a standard somewhere with assumed temperature
for input water and air ambient and some number of gallons heated.???

I can calculate the energy needed to heat the water I use.
I need a way to estimate the energy radiated from the
tank. �I'm way to lazy to try to measure it.
Thanks, mike

They make an assumptiom about how much water you use.
They make and assumptiom about how cold your water is when it comes
into the house.
They make another assumption about how hot you use your water.
They make yet another about how thermally efficient your water heater
is.

A gallon of water wieghs around 10 pounds.
Every pound of water takes 1BTU to raise it 1deg Fah.
There are 3412 Btu in I Kwh.
There yah go. Doncha wish you was metric like us over here?

There are so many assumptions it's all ******** in fact.

Water Heater Energy Use, How calculated?
 

"harry" wrote
A gallon of water wieghs around 10 pounds.
Every pound of water takes 1BTU to raise it 1deg Fah.
There are 3412 Btu in I Kwh.
There yah go. Doncha wish you was metric like us over here?

The news has been full of stories about how Americans are gaining weight. I
never realized how bad it was until now. Even water has gained a coupe of
pounds since I was in school.

Water Heater Energy Use, How calculated?
 

harry wrote:
On Apr 12, 2:12�pm, mike wrote:
My electric water heater has a sticker that says it uses
4720 KWH/year.
How is that number calculated?

I assume there's a standard somewhere with assumed temperature
for input water and air ambient and some number of gallons heated.???

I can calculate the energy needed to heat the water I use.
I need a way to estimate the energy radiated from the
tank. �I'm way to lazy to try to measure it.
Thanks, mike

They make an assumptiom about how much water you use.
They make and assumptiom about how cold your water is when it comes
into the house.
They make another assumption about how hot you use your water.
They make yet another about how thermally efficient your water heater
is.

A gallon of water wieghs around 10 pounds.
Every pound of water takes 1BTU to raise it 1deg Fah.
There are 3412 Btu in I Kwh.
There yah go. Doncha wish you was metric like us over here?

There are so many assumptions it's all ******** in fact.

I'm asking what assumptions they make. The rest is just math.

Water Heater Energy Use, How calculated?
 

On Apr 13, 4:01�am, "Ed Pawlowski" wrote:
"harry" wrote

A gallon of water wieghs around 10 pounds.
Every pound of water takes 1BTU to raise it 1deg Fah.
There are 3412 Btu in I Kwh.
There yah go. Doncha wish you was metric like us over here?

The news has been full of stories about how Americans are gaining weight. �I
never realized how bad it was until now. �Even water has gained a coupe of
pounds since I was in school.

Our gallon in the UK is bigger than yours!

Water Heater Energy Use, How calculated?
 

On Apr 13, 11:28�am, mike wrote:
harry wrote:
On Apr 12, 2:12 pm, mike wrote:
My electric water heater has a sticker that says it uses
4720 KWH/year.
How is that number calculated?

I assume there's a standard somewhere with assumed temperature
for input water and air ambient and some number of gallons heated.???

I can calculate the energy needed to heat the water I use.
I need a way to estimate the energy radiated from the
tank. I'm way to lazy to try to measure it.
Thanks, mike

They make an assumptiom about how much water you use.
They make and assumptiom about how cold your water is when it comes
into the house.
They make another assumption about how hot you use your water.
They make yet another about how thermally efficient your water heater
is.

A gallon of water wieghs around 10 pounds.
Every pound of water takes 1BTU to raise it 1deg Fah.
There are 3412 Btu in I Kwh.
There yah go. Doncha wish you was metric like us over here?

There are so many assumptions it's all ******** in fact.

I'm asking what assumptions they make. �The rest is just math.- Hide quoted text -

- Show quoted text -

You will need to make your own estimates if you want to be anywhere
near accurate.

Water Heater Energy Use, How calculated?
 

"harry" wrote in message
...
On Apr 13, 4:01�am, "Ed Pawlowski" wrote:
"harry" wrote

A gallon of water wieghs around 10 pounds.
Every pound of water takes 1BTU to raise it 1deg Fah.
There are 3412 Btu in I Kwh.
There yah go. Doncha wish you was metric like us over here?

The news has been full of stories about how Americans are gaining weight.
�I
never realized how bad it was until now. �Even water has gained a coupe
of
pounds since I was in school.

Our gallon in the UK is bigger than yours!

Ah, true 8.33 X 1.2 You have both water and money by the pound!

Water Heater Energy Use, How calculated?
 

On Mon, 12 Apr 2010 06:12:30 -0700, mike wrote:

My electric water heater has a sticker that says it uses
4720 KWH/year.
How is that number calculated?

I assume there's a standard somewhere with assumed temperature
for input water and air ambient and some number of gallons heated.???

I can calculate the energy needed to heat the water I use.
I need a way to estimate the energy radiated from the
tank. I'm way to lazy to try to measure it.
Thanks, mike

These numbers are used for comparison purposes. One easy way to
measure usage is to do without hot water for 24 hours and read your
elec meter before/after. Or, connect a kw-hour meter to your heater.

Water Heater Energy Use, How calculated?
 

On Apr 12, 10:01 pm, "Ed Pawlowski" wrote:
"harry" wrote

A gallon of water wieghs around 10 pounds.
Every pound of water takes 1BTU to raise it 1deg Fah.
There are 3412 Btu in I Kwh.
There yah go. Doncha wish you was metric like us over here?

The news has been full of stories about how Americans are gaining weight. I
never realized how bad it was until now. Even water has gained a coupe of
pounds since I was in school.

Andy comments:

Maybe the OP was talking about metric pounds, which are about 25%
heavier...

Andy in Eureka, Texas ..... where everything
is 25% bigger.

Water Heater Energy Use, How calculated?
 

harry wrote:
On Apr 13, 11:28�am, mike wrote:
harry wrote:
On Apr 12, 2:12 pm, mike wrote:
My electric water heater has a sticker that says it uses
4720 KWH/year.
How is that number calculated?
I assume there's a standard somewhere with assumed temperature
for input water and air ambient and some number of gallons heated.???
I can calculate the energy needed to heat the water I use.
I need a way to estimate the energy radiated from the
tank. I'm way to lazy to try to measure it.
Thanks, mike
They make an assumptiom about how much water you use.
They make and assumptiom about how cold your water is when it comes
into the house.
They make another assumption about how hot you use your water.
They make yet another about how thermally efficient your water heater
is.
A gallon of water wieghs around 10 pounds.
Every pound of water takes 1BTU to raise it 1deg Fah.
There are 3412 Btu in I Kwh.
There yah go. Doncha wish you was metric like us over here?
There are so many assumptions it's all ******** in fact.
I'm asking what assumptions they make. �The rest is just math.- Hide quoted text -

- Show quoted text -

You will need to make your own estimates if you want to be anywhere
near accurate.
Ok, but how do I estimate the losses not related to hot water usage?
The rest is just math and I have all the inputs.
Just want to estimate the tank heat losses.
The energy star people have to have a model that can be used to subtract
out the hot water used from the equation to get what I want.
All I'm finding is formulae without input numbers.

And yes, it's gonna be easier to build the tools to measure it than
to get an answer here...hardware is done, just gotta finish the software.
Thanks, anyway...