Electric Hot water heater...Any interest???

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keyman512us

Member
Feb 27, 2007
804
North Worc. CTY MA
Hey all...

Reading some of these posts here in the 'green room' I was wondering what % of people "out there" have electric hot water heaters and of those, how many have 'timers' on them???

Whats the 'general consensus' on how good or bad they (electric HW heaters) are?

How many people out there have a utility company managed (RF control or timer) installed??? It seems (being in the electrical trade) less emphasis is being placed on these items...as well as electric hot water heaters..lol

Anyone still have 'J-Rate' billing for their electric hot water??? (chime in by all means)

Would anyone be 'interested' in a thread describing how the timer works or even perhaps a thread in the DIY section???
 
Don't have a timer or RF control. Well, not quite true. A timer has been sitting on the shelf waiting to be installed for ten years. Since we got the defective control board situation on my Whirlpool straightened out I love the thing. Ok have warm feeling for it, I guess love is too strong a word.

I can't quite figure out why anybody would want gas water heaters when you just wire this thing in and forget where you left it until someday the water turns cold or you hear water running into the sump. Never heard of an electricity leak blowing a house up. Or a woodpile leak doing it either for that matter.
 
I can’t quite figure out why anybody would want gas water heaters when you just wire this thing in and forget where you left it until someday the water turns cold or you hear water running into the sump. Never heard of an electricity leak blowing a house up. Or a woodpile leak doing it either for that matter.

Recovery time, overall efficiency. My NG heater recovers in half the time of an electric and the overall efficiency if you include the losses of electricity generation and transmission, the NG heater is more efficient (@65%). This is particularly true if you had a full condensing NG heater. (95% efficient)

Electricity generated is about 40% efficient (Except for Hydro, Wind, Solar) times heater efficiency of about 97% times line loss 5% = 36.9% efficiency.

Natural Gas - Fired 65% times transmission loss of 5% = 61.75%

NG is more efficient overall.
 
TMonter said:
Electricity generated is about 40% efficient (Except for Hydro, Wind, Solar) times heater efficiency of about 97% time line loss 5% = 36.9% efficiency.

Natural Gas - Fired 65% times transmission loss of 5% = 61.75%

NG is more efficient overall.

Aha! Got it. Thanks for the explaination.
 
TMonter said:
I can’t quite figure out why anybody would want gas water heaters when you just wire this thing in and forget where you left it until someday the water turns cold or you hear water running into the sump. Never heard of an electricity leak blowing a house up. Or a woodpile leak doing it either for that matter.

Recovery time, overall efficiency. My NG heater recovers in half the time of an electric and the overall efficiency if you include the losses of electricity generation and transmission, the NG heater is more efficient (@65%). This is particularly true if you had a full condensing NG heater. (95% efficient)

Electricity generated is about 40% efficient (Except for Hydro, Wind, Solar) times heater efficiency of about 97% time line loss 5% = 36.9% efficiency.

Natural Gas - Fired 65% times transmission loss of 5% = 61.75%

NG is more efficient overall.

Just out of curiousity?? Do those efficiency #'s take into the equation "the natural draft losses" of having basically a 'chimney' in the center of a NG water heater??? <Curious>

I live in the city and "have access" to NG...but the gas company Unitil (or 'wait until'...as it's customers refer to it as) charge an arm and a leg for NG... coupled with the fact that personally, IMHO, NG ranks right up there with using whale oil as a fuel, (besides the fact I wouldn't feel safe having NG in the house) I won't be switching anytime in the 'near future'.

Might be more efficient...but it's more expensive (about twice the cost of electric) in this neck of the woods. ;)
 
I have an electric heater and no timer. Seems to work great. As noted above, it's 97% efficient, silent, just works, and no NG is available. No chimney to leak, no CO to be made. I don't know, it seems like a pretty good deal. What good would the timer do? I use hot water at 11PM and then again at 6:30 AM.
 
Just out of curiousity?? Do those efficiency #’s take into the equation “the natural draft losses” of having basically a ‘chimney’ in the center of a NG water heater??? <Curious>

I live in the city and “have access” to NG...but the gas company Unitil (or ‘wait until’...as it’s customers refer to it as) charge an arm and a leg for NG… coupled with the fact that personally, IMHO, NG ranks right up there with using whale oil as a fuel, (besides the fact I wouldn’t feel safe having NG in the house) I won’t be switching anytime in the ‘near future’.

Might be more efficient...but it’s more expensive (about twice the cost of electric) in this neck of the woods. wink


Draft losses really play no part in the thermal efficiency of most water heaters. I'm sure if there were no draft loss you could get better overall efficiency, but it wouldn't be much.

The real number efficiency is gross energy delivered in BTU by the gas to heat transferred into water in BTU. Electric is more efficient at the heater, but not in the entire scheme of things.

Just out of curiosity, what is the cost per therm or decatherm in your area for gas?
 
The plumbing/heating guy just came this afternoon to replace the "smart" gas valve in my 4-year-old gas (propane) water heater. I don't have the bill yet, but I bet it's going to be a lot more than I saved by not getting an electric water heater. Moving parts + damp basement + seasonal usage = $$$. A few years ago our new gas stove was delivered with a faulty valve and vented a whole bunch of propane into the house, which besides the safety issue also probably cost me more than I saved vs. an electric stove. So perhaps I see BB's point. Although, while in general "electricity leaks" don't cause explosions, they are a leading cause of fires.
 
I have an on demand electric heater since I kicked the gas company off my property. I like it a lot, but am thinking about adding a second unit. The point of use units are, in my experience, are great deals if you have a low to moderate use level. Can't say about high use. I have no hot water lines and tanks that need to be kept heated, and as a result if I don't use hot water for twelve hours, it doesn't heat anything. I have no idea what it costs, but the base bill for gas, before I terminated was about $40. in the Summer and the only gas was for water. Now I average less than $40 for electric, a little higher in the late Winter, but not much. Think I am saving a bunch. BTW, the biggest savings is letting Albertson's keep my frozen and refrigerated food for me. :)
 
I have a 3200 sq ft home in New England that was 100% electrically heated when I bought it. (baseboard) The house is super insulated. 2x6 walls then 1/2 inch foam board then sheetrock.

Since then I have tracked my costs and they really are not that bad. Over the past two years Northeast Util. has jacked up the prices big time. Thats when I started burning wood. I now only use my Electric in about 2- rooms in the house. My Woodstove does the rest. Overall I'm very happy with my home heating... No oil to furnace or boiler to maintain or clean... I have a real turnkey home. WIth wood, the majority of my home is about 75 degrees in the coldest months

If I didnt use the stove i'd be paying about 5-700 dollars a month during the coldest months.

Tell me how would a timer help me with my 80 Gallon Elec. Hot Water heater?
 
TMonter said:
Just out of curiousity?? Do those efficiency #’s take into the equation “the natural draft losses” of having basically a ‘chimney’ in the center of a NG water heater??? <Curious>

I live in the city and “have access” to NG...but the gas company Unitil (or ‘wait until’...as it’s customers refer to it as) charge an arm and a leg for NG… coupled with the fact that personally, IMHO, NG ranks right up there with using whale oil as a fuel, (besides the fact I wouldn’t feel safe having NG in the house) I won’t be switching anytime in the ‘near future’.

Might be more efficient...but it’s more expensive (about twice the cost of electric) in this neck of the woods. wink


Draft losses really play no part in the thermal efficiency of most water heaters. I'm sure if there were no draft loss you could get better overall efficiency, but it wouldn't be much.

The real number efficiency is gross energy delivered in BTU by the gas to heat transferred into water in BTU. Electric is more efficient at the heater, but not in the entire scheme of things.
Just out of curiosity, what is the cost per therm or decatherm in your area for gas?

Why on earth is electric not as efficient is the entire scheme of things? The heater is nearly 100% efficient at converting input energy to hot water, the thing is just as well insulated as a gas heater, same stanby losses, same line losses, no stack losses though and seemingly much cheaper and easier installation. My electric "btu" is very cheap, I don't care how the power company makes my watts. Are you perhaps trying to consider efficiency losses at the powerplant?
 
gman1001 said:
I have a 3200 sq ft home in New England that was 100% electrically heated when I bought it. (baseboard) The house is super insulated. 2x6 walls then 1/2 inch foam board then sheetrock.

Since then I have tracked my costs and they really are not that bad. Over the past two years Northeast Util. has jacked up the prices big time. Thats when I started burning wood. I now only use my Electric in about 2- rooms in the house. My Woodstove does the rest. Overall I'm very happy with my home heating... No oil to furnace or boiler to maintain or clean... I have a real turnkey home. WIth wood, the majority of my home is about 75 degrees in the coldest months

If I didnt use the stove i'd be paying about 5-700 dollars a month during the coldest months.

Tell me how would a timer help me with my 80 Gallon Elec. Hot Water heater?

Gman, Sounds like you got a good setup going.

To answer your question, and others...It all depends on what size heater you have and how much hot water you use.

Timers (both utility and consumer installed) aren't all that popular these days...but 20-30 years ago they were all the rage. Partly because efficiency and technology has increased and the benefit is not as great anymore.

I would say a 50 gallon heater is the 'squeak point' so to speak. At less than 50 gallons it's not worth it, 50 and above it might be worth considering, 80 and up some potential.

First you have to consider how an electric hot water heater works (very important to the equation). Larger hot water heaters (generally anything above 30 gallons) heat the water by use of TWO heating elements (generally 4500 watts) that are "interlocked". Only one element will "fire" at a time....but will constantly maintain temperature 24/7. If (in your case) you have an 80 gallon tank you are constantly heating 80 gallons of water. A timer can be installed for "long periods of rest" to inhibit the lower element from 'firing'...seeing as heat rises, by doing this you cut the size heater in half and energy use in half also. Recovery times for electric HW heaters (while a little slower than NG) are fairly quick...so the inconvience factor is minimal (if the set times are 'coordinated' just right). It's like this: "X"% of the time you need minimal hot water, so a 40 gallon heater would be more than adequate...but there may be times (say when everyone in a family of four let's say) are going to be using the hot water so that 80 gallons gets pressed into service.

Kinda along the lines of 'working smarter not harder'.

Where the utility is concerned the benefit gets a little more 'shady'. In the 'old days' (in my area for example) some utility companies offered "J-Rate Billing"..."They made a deal...they worked with you" so to speak, but the time curve worked in reverse so to speak. They would install a seperate meter specially wired with a "5th and 6th terminal" that was basically a "switch leg" that would inhibit the lower element (generally from 7AM to 4PM or even as late as 10PM depended on the utility and the plan you wanted) by signing up for this "offer" you got a specifically reduced rate solely for your hot water. This was the best deal going, discounts could be in the neighborhood of 35% or more because for the utility this was in effect a "one way battery".

Enter the 80's...and the microprocessor:

The utility's went "high tech" and took it a step farther (In theory anyway). For example MECO (Massachusetts Electric Company) part of the "NEES family" (New England Electric System...the good old days...ahhh) had some great ideas that for whatever reason dropped by the wayside...go figure. MECO had always offered it's customers "water heater rental service". They instsalled, owned and maintained the tank all for a monthly fee. So they decided to try something new, using 'thier heaters' as a test...with the ultimate goal of setting up all heaters (company or private) on the 'new system'.

They installed an RF microprocessor controlled 'system' right in your home. They could 'que' your water heaters lower element to shut down during periods of high demand on thier system as a "load shedding" method. Two boxes were installed, one on the tank to do the switching, connected by a low voltage cable to the RF reciever mounted on the back of the house...fairly discreet. Both boxes had LED's to indicate the status of your water heater.

Sounds complicated but it was fairly simple in reality...at any rate it fell out of favor, more than likely because it got in the way of profit $$$'s.

From an enviromental standpoint this could be considered a "green idea" when you really think about it...brought about from the people that brought us the 'bear swamp project' (pumped storage hydro project in western MA).

"...This ain't your Grandfathers NG water heater..." lol ;)
 
hmmm, interesting...

Check this out.. about 5 years ago CL&P (CT Light & Power) offered to all home owners with electric heat a heat pump system that piggy backed on an existing Electric Hot water heater.

They installed it for a fee of 150 bucks. So I bit. Thing never paid off although my bills didnt go up either so I left it for a few years.

Turns out the systems were faulty and had bad circuit boards.

The idea is great and does work, just need better equipment. The documented side benifit was that you could duct the heat pump into an upstairs room for cheap air condiitioning! I never did that but it sounded good.

The system was called "Hot Shot Hot Water Heater"
 
OK, what about an electric tankless water heater? I have been looking at replacing my 40gl ng water heat with a tankless and I like the idea of silent operation of electric. Would an electric tankless water heat be more efficient than a tank one?
 
Current electric tankless water heaters are not capable of high flow rates without extremely high input amperages. Currently limited to point of use rather than whole house solutions. To answer your efficiency question, yes, the tankless design would not suffer standby losses and would be more efficient in floor space too.
 
Somebody posted an article last year about the effect of a large number of tankless units on the electric utility. Seems at the peak hot water usage times of the day, morning showers and early evening, if a bunch of them are in use it can knock the utlity to its knees with the usage spike whereas the stored water units level out the electricity usage.
 
I doubt there are enough people running tankless in my area to bring the electric company to it's knees. I want to go with the most efficient system I can find. The elec tankless one that I'm looking at is rated at 3.3gpm with 55 degree water source. They say that is enough to run a shower and another tap in the house. Does that sound right?
 
Depends on the shower head and faucet restrictors. My low flow heads are 1.5 gpm and the faucet aerators are at least that much. How many amps does that heater take? A typical electric tank only uses 30 of 220. Figure that your hose can shoot 15 gpm.
 
I always thought A/C was what brought electric companies to their knees, not water heaters. Our electric company in MD (PEPCO) used to have a "killowatcher" program where you got a discount if you let them wire a remote controller into your A/C unit so they could reduce its duty cycle under heavy summer loads. Our house had one when we bought it, but I don't ever recall noticing it in action. Until it broke and kept my compressor from turning on at all one spring, at which point I unwired it. A couple of months later they ended the program.
 
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