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Water Heater Question

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Re: Water Heater Question
Post by Daryl   » Wed Apr 06, 2016 8:29 pm

Daryl
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T2M, in the topic preceeding this I did say that things may be different elsewhere, and you have proved this. Our "vast" distances come from having a sparsely inhabitated continent that has lots of coal and gas.
We get such good prices for exporting our gas to Asia that most of our power stations are big smelly coal burners that are built in isolated areas. In your case I agree that electricity may well be more efficient than bottled propane, although I still reckon that a free to run solar system would be better still.
Incidentally I forgot to mention one advantage here of electric storage systems. A big enough one can be set up to heat in the early hours of the morning, using cheap stand by power.
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Re: Water Heater Question
Post by tinfoil   » Wed Apr 06, 2016 8:34 pm

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Lets make sure that we understand exactly how an electric heating element works:

ALL of the energy 'lost' in such an element becomes heat. 100%. If this element is immersed in water, then 100% of the electric energy has gone into heating the water.

An induction heater CANNOT be better, and can be worse, like on a cooktop, as some of the heat is lost to the room's air, or must heat up the pot to heat up the water. The energy to heat the pot itself is not 'free'.

As already pointed out, it gets complicated when you STORE hot water, because you have to factor in heat loss rates, insulation, etc.

Using a fossil fuel to make heat has its own problems, as some of the chemical energy becomes heat, some does not. Some of the heat made is useful heat, some of it is not.

In general, a larger heating device makes heat more efficiently than a small one.

That's why central heating plants are often favored over small units in many buildings. Even after factoring in losses in the pipes between buildings, a central plant CAN produce the same overall heat using less fuel.


BTW, in North America, a typical city electrical distribution has about 4-6 % 'technical losses' from the central transformer station(s)

A typical transmission grid has about 4-9 percent losses overall country-wide.

A large electrical generator extracts about 40% of the available chemical energy in the fossil fuel as electricity, and many such plants do useful things with the 60% 'waste' heat (google for "combined cycle")

A typical large boiler gets about 70% of the chemical energy out as useful heat. I do not know the statistics about costs to get the natural gas or propane to the facility that will consume it.
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Re: Water Heater Question
Post by DDHvi   » Wed Apr 06, 2016 10:12 pm

DDHvi
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Using energy to move heat, as in heat pumps, air conditioners, and refrigerators, produces more heat per unit energy than a heating element. However lower entropy energy is needed to drive the process. This higher availability energy is likely to cost more, although the multiplication factor may make it worth it.

OTOH, solar can reach temperatures that will run absorption heat pumps, especially with evacuated tube collectors.

The primary problem is the higher cost for the equipment. Often either a loan is required, or the price must be taken from savings. There are heat pump water heaters, which might be a good investment if you also want to remove humidity from that volume.

For low temperature heat, sometimes it is possible to spend a little energy to improve comfort. It is spring in this hemisphere. On a sunny day the solar on the south side of this house will rise to about 30 degF above outside temperatures. Often using only a little electricity to run the fans is enough for comfort. In addition, air leaving the living volume goes through the basement. The ground under the house is 6 degF warmer than February, and 14 degF warmer than when we started, seven years ago. We are also slowly installing "wing" insulation to reduce losses thru the ground. With a little modification, this could be used to preheat DHW before it reaches the primary tank. Again, equipment costs make it impractical while propane is low priced.
;)
Douglas Hvistendahl
Retired technical nerd
ddhviste@drtel.net

Dumb mistakes are very irritating.
Smart mistakes go on forever
Unless you test your assumptions!
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Re: Water Heater Question
Post by thinkstoomuch   » Thu Apr 07, 2016 1:21 pm

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Daryl wrote:T2M, in the topic preceeding this I did say that things may be different elsewhere, and you have proved this. Our "vast" distances come from having a sparsely inhabitated continent that has lots of coal and gas.
We get such good prices for exporting our gas to Asia that most of our power stations are big smelly coal burners that are built in isolated areas. In your case I agree that electricity may well be more efficient than bottled propane, although I still reckon that a free to run solar system would be better still.
Incidentally I forgot to mention one advantage here of electric storage systems. A big enough one can be set up to heat in the early hours of the morning, using cheap stand by power.


Tip of the hat I to tinfoil. Very good information.

I agree with you on solar heating. A inline system doesn't physically preclude the use of one. As a matter of fact it will be more efficient for a given value of hot water out.

warning label political stuff comes up.


The problem to my view from a vast distance :lol: is known as NIMBY (not in my backyard.) FPL cheated quite a bit when they built that nearest CCS plant. When they built the original oil fired plant it was empty swamp land. Now it is a suburban sprawl with an ocean view quite close by interspersed with light industry. Also NIMBY is the reason that other plant is so far away.

But they still owned the land in Riviera Beach and the nasty oil plant was still in operation. So recently to improve the bottom line they said lets modernize. Knocked down the old inefficient plant for a "modern" (that old plant was "modern" when it was built) CCS. Which saved the company money, saved me money and improved the bottom line. Oh yeah and was much better use of resources and less affect on the environment.

It is a classic case of the benefits of capitalism. Everybody wins.

From what you are describing of the way yours working is a classic case of entrenched interests, not going into what clothes they are wearing. Assisted by NIMBY.

Though if you go back to the 80's and before FPL was apparently a case for the problems with capitalism. The reason they had that old oil fired plant to get rid of.

The US has wonderful examples of NIMBY all over the place. Not least coal fired plants in the plains feeding say, Chicago hundreds of miles away. Though the Plains wind farms are another.

It can get worse look at how much money a concentrated solar power plant in the desert spent to protect the desert tortoise. Would that be NIDTBY? :lol: :lol: :lol:

end of political stuff hopefully


Have fun,
T2M
-----------------------
Q: “How can something be worth more than it costs? Isn’t everything ‘worth’ what it costs?”
A: “No. That’s just the price. ...
Christopher Anvil from Top Line in "War Games"
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Re: Water Heater Question
Post by tinfoil   » Fri Apr 08, 2016 10:06 am

tinfoil
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Theres a LOT of interesting facts to be found in https://www.csu.edu/cerc/researchreports/documents/CarbonFootprintofWater-RiverNetwork-2009.pdf

The part about water heating starts on page 17
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Re: Water Heater Question
Post by thinkstoomuch   » Fri Apr 08, 2016 11:40 am

thinkstoomuch
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tinfoil wrote:Theres a LOT of interesting facts to be found in https://www.csu.edu/cerc/researchreports/documents/CarbonFootprintofWater-RiverNetwork-2009.pdf

The part about water heating starts on page 17



<Rubs hands gleefully>

Thank you thank you thank you ...

Granted no matter what I was going with the electric, tankless or not was a question. I really wanted to get rid of the tank more from the water damage and related worries perspective than efficiency.

Thing that made it tankless was when I figured out how relatively easy it was to install in this house. Like I said pull six wires (in existing conduit) install two 220 volt breakers(remove one). Modify existing plumbing and install two valves.

I spent more time contemplating than doing. Did I mention I think too much. And you just fed the addiction. Thank you.

I do get asked questions by friends, A LOT. Especially for any DIY project. For which this topic has helped me when I my opinion is asked.

Thanks again and Have fun,
T2M
-----------------------
Q: “How can something be worth more than it costs? Isn’t everything ‘worth’ what it costs?”
A: “No. That’s just the price. ...
Christopher Anvil from Top Line in "War Games"
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Re: Water Heater Question
Post by HB of CJ   » Sat Apr 09, 2016 9:16 pm

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Regional situations also enter into it. Out here in South West Oregon, USA, we are still gleaning cheap hydro electric power from the large Bonneville and Grand Collie dams that were built back in the 1930s. We were told such construction was intended somewhat for WW2 aluminum production. Electric smelting.

Our electricity costs about $0.048 cents per kilowatt hour for under 1000 kilowatts per month. More if you use it. The mundane instant induction type electric hot water heaters work very well. A slight learning curve and habit obtaining period is required. All things considered, very efficient (for us) hot water production.
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Re: Water Heater Question
Post by thinkstoomuch   » Fri May 13, 2016 5:53 am

thinkstoomuch
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Posts: 2727
Joined: Mon Aug 24, 2009 1:05 pm
Location: United States of America

HB of CJ wrote:Regional situations also enter into it. Out here in South West Oregon, USA, we are still gleaning cheap hydro electric power from the large Bonneville and Grand Collie dams that were built back in the 1930s. We were told such construction was intended somewhat for WW2 aluminum production. Electric smelting.

Our electricity costs about $0.048 cents per kilowatt hour for under 1000 kilowatts per month. More if you use it. The mundane instant induction type electric hot water heaters work very well. A slight learning curve and habit obtaining period is required. All things considered, very efficient (for us) hot water production.


I have been contemplating many of the things that came up in this thread. Yes I do in fact think too much. Unfortunately not well.

As you say local differences will come into play for what makes the most ecological and commercial sense.

For example for me 15% of the electricity is generated by nuclear energy. (should be twice that different story). Also something I did not think about Palm Beach has two Waste to Energy plants within 10 miles of the house. Only produced 10% of the energy of the nearby CCGT plant but every little bit helps.

So if comparing propane to electric ecologically electricity seems to win, here. Natural Gas not an option no infrastructure.

Economically even a solar hot water heater loses here. Not sure on the energy return for investment at all.

Daryl,

I am still trying to find something on the costs for propane transport. And failing miserably. Though I now understand why it is so popular the cost to make it a liquid is cheap(can and is used as a refrigerant). So it ends up being more of how far to the distribution point and how it gets to each hub which will vary widely.

In other words there is no one answer again.

Thank you all for giving me stuff to think about,
T2M
-----------------------
Q: “How can something be worth more than it costs? Isn’t everything ‘worth’ what it costs?”
A: “No. That’s just the price. ...
Christopher Anvil from Top Line in "War Games"
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