Is 220V Baseboard Heater More Efficient Than 120V?

No... watts are watts are watts.

Doesn't matter if you already have a 220V outlet. Otherwise the cost of the 220V wiring makes this a non-starter.

See #1, above.

The wiring for a 3000W 240V heater is the same size as the wiring for a 1500W 120V heater; only the color of the wiring changes, which can be accomplished by painting or taping.

Electric resistance heating is 1.00 (i.e. 100%) efficient in terms of electrical energy in versus heat out. With 240V versus 120V, for the same current (and wire size) you get twice the heat.

Maybe I misread the question.

"Is there a efficiency gain by wiring in a 220V?"

To me that means running a 220 V circuit for the heater.

You had the right answer the first time. 120 vac for a given watts heater will be twice the current as the 220 vac heater. Watts is watts..

You posted:-

"The wiring for a 3000W 240V heater is the same size as the wiring for a 1500W 120V heater; only the color of the wiring changes, which can be accomplished by painting or taping."

I feel that is simply not enough and could lead someone into serious danger, as I am aware that the heater in 240 VAC is connected to both hot leads of the same phase in US households, and the casing should be be grounded to ground of course!

But as the ground is also connected to neutral at some point, somewhere, which is the center point of the same single phase (I assume that a US house does not get more than one 240 VAC phase in the house).

There is possible danger to the user if there is not:-

1) Double pole on off switch on the device, breaking both hot phase connections.

2) An over current plus RCD device with 2 poles.

I am personally a great believer in RCD devices (Wiki uses this name, not the US names), which could help save a life where a short with regard to the heater element and the frame ground occur.

We had a recent blog on CR4 where water heaters boiled even when switched off, due to failures in the electrical installation/device which were not "covered" by the "usual" US mains installations it would seem.....

The same could happen here.

(This gave me a "heads up" that the 240 VAC 50 Hz system used mainly around the world, is in fact safer than the US 240/120 VAC system, simply because one end of a phase is already grounded/Neutral.....)

What US electrical code, if any, should be applied to the installation of 240 VAC devices in the USA to prevent such things when they go wrong, possibly causing major hazards to life and limb?

The only way I see it is to have such devices powered via say a RCD plus over current circuit breakers both using double pole connections. (Assuming that a single device, fulfilling both functions is not in use!)

What is your take?

You said...

"(This gave me a "heads up" that the 240 VAC 50 Hz system used mainly around the world, is in fact safer than the US 240/120 VAC system, simply because one end of a phase is already grounded/Neutral.....)".

I disagree that the 240 volt system that is grounded at one end is safer. Why... simply because the potential present in the system is 240 volts to ground where in the North American system the potential is only 120 volts to ground.

In fact... the NA system of a split phase system was developed to lower the potential to ground that was present in the system you prefer.

Is there a web site somewhere that reports electrocution per capita? I could not find anything useful.

The reason I said it, was to see who could reply with some good statistics, as of this moment, none.

I am certain that there must be fewer deaths in the UK as there have been laws about RCD installation in domestic situations, I believe for around 40 years. I am sure that someone from the UK can give more exact details.

As far as I am aware, there are only requirements for bathrooms and wet areas in the USA to have such safety devices, correct me if I'm wrong. Plus, in slightly older houses, many sockets are only 2 pin in the USA, whereas the UK has all 3 pin sockets and plugs....

I can only say that since about 1975, I have never lived in a house without an RCD.....or their equivalent.

Also, the UK has a fuse in every plug, so that there is not the problem as in many countries, where if the fault current is below the trip current of the fuse or breaker, the fuse or breaker does not drop.

Provided a little bit of common sense is used and a fuse of the little bit more than the expected current of the device on the end, then it will break with a smaller fault current, only dropping power to that device, not to everything on that breaker.

Sadly, some UK people just stick in a higher current fuse than needed....their problem.

Furthermore, many countries use 16 amp breakers (Germany), the UK's maximum fuse size for 13 amp plugs, is surprisingly 13 amps!!

The USA has I believe 20 amp breakers/fuses for domestic outlets.....higher for 240 volt supplies for cooker and the like.......

The dangers of 240 VAC heater elements developing a ground fault in the USA, then overheating even with the power switch set to off, simply cannot happen in the UK.

No central neutral/ground.

Plus RCDs would trip.

See here:-

http://electrical.theiet.org/wiring-matters/54/rcd-protection-of-sockets/index.cfm

or here:-

http://en.wikipedia.org/wiki/Residual-current_device

Perhaps you can post some interesting links supporting your thoughts?

I agree fully with you that the RCD/GFI device is a excellent safety addition.

I am only talking about which of the two systems, the NA 120/240 volt system verses the 240 volt one you mentioned, is safer from a voltage potential aspect.

I see no advantage whatsoever from grounding a source at one end or in the middle?

Let me see if I can find a link or two that talks to why the NA split phase system was developed.

We have already had people here on CR4, from the USA, who have had hot water heater elements, on 240 VAC, getting a short to ground and the half phase of the element is permanently on via ground/neutral!

Boiling water and steam can result. Safety devices in such units MUST remove BOTH sides of the phase, not just one....

Even though the off switch or even the inbuilt thermostat has theoretically "removed" power.

That simply cannot happen if there is no central ground/neutral.

In the UK and most of the world, only one side is "live", the switch and thermostat are placed in the live side with correct wiring (follow markings and or colour!) as in any country.

Either one being turned off and no power flows even with a damaged element.

A short to ground "close" to the live side will drop the fuse or breaker.

A short to the neutral ground side will ONLY be noticed if an RCD is in circuit....almost like "normal" operation.

I hope I have explained how a central neutral/ground has serious drawbacks when only one end of the phase is switched for 240 VAC loads......

I am sure that this is known and understood in the USA, but my original question has not be answered, "How is such an 240 VAC heater installation built/installed safely in the USA?"

The certification process that certified that piece of equipment for use in NA was in error. It never should have been certified for use in NA with the ability to break only one leg of the supply circuit.

I agree.

But as 220 VAC is "available" inside US houses, how should such equipment be installed, or how should the equipment be internally designed to prevent such problems?

Who there (USA) and here (CR4) really knows?

The only "single" bit of kit that easily would "partially" fix the problems, is an RCD. But that is only part of the problem.

The other dangerous part is that someone, doing maintenance on such equipment, pulls only one fuse and gets a shock from the other "leg". They will be very happy to find that an RCD has saved their life I am quite sure!!! But still, its only a partial fix!!

That part could possibly be fixed by requiring all 220 VAC equipment to be fed from a dual breaker, where both poles are mechanically linked and therefore disconnected at the same time.....

But up to now (hope I haven't missed anything!) nobody has mentioned how US code handles such things, which to me is an even bigger danger in itself!!

Potentially, this center tapped Neutral/Ground, could really kill people one way or another!! Which is why I said recently, having lived for many years in countries who use 240 VAC, but where NO center tap is used, just one leg of each phase is bonded and declared as a neutral, I find to be intrinsically safer.

I prefer especially the UK version which is SO far ahead of the rest of the world in safety, that few outside of the UK electrical industry can appreciate it fully. (And it stems from the end of WW2 and is therefor nothing new!)

Even in Germany, the standard single phase mains plug can be inserted in two ways (France uses the same plug, but with an extra earth pin to allow only "one way", but no fuse), 180° to each other, so there is no possibility to have fully controlled, which leg is neutral and which is phase. So all equipment still NEEDS a double pole switch to be safer, but doesn't always have one!!!

Even RCDs here, though actively promoted for many situations, are rarely seen in pre 1984 housing!!

I actually "know" of only two private houses with them, my house (of course) and my daughter's house......

Just to horrify the US citizens, I have a large socket installed in my cellar, which allows my to pick up with a single 5 pin plug (physically large!), 3 phases, neutral and ground, just in case I want to use 3 phase equipment, up to 65 amps per phase, or even run a garden party and need extra single phase lighting and power.....

I can simply leave a cellar window open and run the cable from the house into the garden for example.....all fused with CBs and also on 3 RCDs.....just in case!!

It is seldom used.

Now that you have hijacked another thread with off topic material with several long posts, I feel the need to respond. First of all, you could google to find US codes, which I am not an expert on, but I can tell you that every home I have examined has double breakers for 240V which are mechanically linked. Second, with the center tap on the 240V line, a short on one side will trip the breaker, so one side of a water heater can not be on full time as you have said. Third, from your own descriptions, it seems that things are more dangerous in Germany, especially old homes. Fourth, one danger you didn't mention is when you are working on something electrical and your brother comes home and sees all the breakers turned off and turns them on again (that happened to me).

Loved it!!

Your Dumb Brother bit!!!

But we were always taught to hang a warning notice on such breakers, or the whole electric box and hope that the dummies could at least read!!

I hope your DNA is significantly different.....But you appear to link safety aspect with hijacking, interesting....

You have obviously little experience of my posts, I ALWAYS address the safety aspects of electrical installations, which I believe MUST FORM part of the answer, ESPECIALLY when the OP shows a significant lack of knowledge...

I am pleased to hear that the breakers are mechanically linked, that is a small step in the right direction.

You were I believe, the first (other than myself) to mention that....

What is your personal take on the situation, mentioned several times already (also on other blogs here some months ago), that even such dual breakers will not handle, where for example, a water heater is switched off, but with a single pole switch, and it develops a ground fault, somewhere in the middle of the element, that does not draw enough current via ground to drop the breaker........but overheats, uncontrolled.

All due to the middle point Ground/Neutral?

Of course an RCD would drop power in such situations, if one was fitted....but they are seemingly unpopular in many countries....or code does not require them for any/all situations.....the US for example.

Andy,

Why don't you just give it a REST!

You said "That part could possibly be fixed by requiring all 220 VAC equipment to be fed from a dual breaker".

Even as feeble minded as I am, it only took 5 minutes to find this, which clearly states the obvious, it is already required by code.

NEC 2008
210.4 Multiwire Branch Circuits.
(B) Disconnecting Means. Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.

Let's all quit beating a putrid horse and agree that for the purposes of this discussion there is NO difference in efficiency between a 120V heater and a 240 V heater.

Let's all quit beating a putrid horse and agree that for the purposes of this discussion there is NO difference in efficiency between a 120V heater and a 240 V heater.

I agreed a long time ago, so if your dead horse is now putrid, thats your problem, which is why I did not see any point to do it online as there were some excellent posts on that point alone, you got there in the end!!

I am the safety conscious Guy, but at last you answered my query of days ago, about what US code requires! Well done!!

BUT, as I have already mentioned, there still could be a dangerous failure, even with a switched off 220 VAC heater, with such a breaker just as you mentioned, that could overheat, but still not draw more current than the CB is set for, so no trip....

So to my mind, to be 100% sure, an RCD or equivalent needs to be added....I feel that its a "bug" in the US designed domestic mains system, that according to you (you never mentioned RCDs or similar), still has not been 100% addressed.

Or did you leave something out of the code post you made? I looked around on the web and only found that RCDs are a US requirement in "wet" areas only.

Is that still true?

There may be other methods to render such things safer, but up till now, I have not seen them posted here.....

Thanks in advance for a friendly (one day?) and factual reply for a change!!

And you're still obsessed with wasting everyone's time proving a non-existent point that no one cares about!

<unsubscribe>

At Last!!! Its suddenly gone quiet!! Am I now deaf?

"Electric resistance heating is 1.00 (i.e. 100%) efficient in terms of electrical energy in versus heat out. With 240V versus 120V, for the same current (and wire size) you get twice the heat."

Not so.

If you apply 240V to a 120V 1500W heater the heating element will burn into.

The resistance of the heating element remains the same so doubling the applied voltage will double the current to 25 amps through the element which is only rated for 12.5 Amps and it will fail very quickly.

The OP would have to replace the 1500W 120V heater with a 3000W 240V heater unit in order to gain more heat.

Like North and Lyn stated, no gain in efficiency, but you can gain a greater heat output because you can buy a larger heater because you'll have more power: Watts = Amps x Volts so a 220v/40a circuit puts out more power than a 110v/20a circuit.

But a resistance heater is damn near 100% efficient so BTU Output to Watt Input doesn't change and your charged for power (watts) not current.

Also, remember that residential US electrical service is via 2 110v supplies. 110v receptacles are supplied off one of the supplies and 220v receptacles are supplied off both the supplies. So gains losses in the conductors/transmission will be essentially a non-factor.

*sigh* The OP is not going to rewire their house and the length of cable on the actual heater isn't going to provide any noticeable/measurable impact on their electric bill, which is the driving reason behind the question, I presume.

I also assume that you're the down-voting poltergeist as well.

All electric heaters are about 100% efficient.

If more heat is required, wiring in the same wattage heater designed for 220V onto a 120V supply will result in a lowering of the heat output by a factor of 120²/220².

There is no efficiency to be gained, but there is a lower amperage demand on the wiring for the same amount of heat and this may add to the safety and dependability of the install....amps x volts = watts.... watts divided by volts = amps... So an important question is how many watts of heat do you need? What existing wire size, and number of conductors? Heater size in watts....The 220 circuit would require smaller wire = cheaper.....A regular 15 amp circuit at 120v would be maxed out at about 1500 watts, with nothing else on the circuit....So the wiring is a decision made by the electrician to accommodate the desired heater size...Oversizing the circuit by about 30% reduces stress on the electrical components...

Yes, but only a small amount of increased efficiency. A 1,500 watt heater will draw the same wattage at the source of the electricity (not where it is used). The power available at the heater is lower due to the resistance of the wire supplying the heater from the source,

A hypothetical example could be: at 240v a 1500 watt resistive heater will draw 6.25 amps at the source of the power. Due to the resistance of the wire from the source to the heater there is not 240v available at the heater. If the wire has a hypothetical resistance of 1 ohm/100 ft (I=E/R, E_(drop) = I*R), therefore voltage drop (E) as read at the heater is 6.25amps * 2 ohms (2 wires, 100ft each) = 12.5 volts drop. 240v - 12.5v = 227.5 volts at the heater. The power from the heater then becomes, Power = Voltage*Current = 227.5v * 6.25a = 1,421 watts produced.

It is the same calculations but different values for 120 volts. 120 volts supply at the source; 1,500 watts at source; current used at source = 12.5a, wire resistance 1ohm/100ft. Therefore the available voltage at the heater is voltage drop = 12.5a * 2 ohms (wire resistance = 200 ft * 1 ohm/100ft) = 25 volts voltage drop; 120v - 25 volts = 95v available at heater; therefore Watts = 95 v * 12.5 a = 1,187 watts

The 240 volt heater is more efficient because there is more power available at it; (P=I*E, wattage)= 6.25a current * 227.5v voltage = 1,421 watts.

Efficiency of 240v heater = 100% * 1,421watts / 1,500 watts = 94.7% efficiency. Efficiency of 120v heater = 100% * 1,185watts / 1,500 watts = 79% efficiency.

Remember, all of the above is hypothetical but illustrates the situation.

Thus, you are better off with the 220v wiring than the 120 volt wiring, when all wiring and the heater are considered.

Good Luck, Old Salt

If the I²R losses in the wires radiate into the house, then it won't make any difference to the useful heat delivered.

It won't all be, so there is a small increase of efficiency using 240V. Probably not enough to justify a new installation.

Whilst true it does depend upon the location in which those losses are released. If they are not into the desired location then the original poster may not achieve quite what is wanted. Just sayin'.

That was the "if" part of my comment.

Your examples are very misleading and present a situation that would not exist.

Copper wire of the gauges that would be used for this purpose (12 and 14 AWG) have resistance values nowhere near what you have presented.

14 AWG = 2.5 ohms per 1000 ft... and not 100 feet as you have indicated.

and...

12 AWG = 1.6 ohms per 1000 ft... and not 100 feet as you have indicated.

You may want to redo your calculations.

North of 60-

Despite your comment, the examples are not misleading. They present the answer in an easier to understand method than using conventional data could ever do. Also they do present a situation that does exist. The formulas presented and used are all correct and are the standard formulas used for calculations of currently existing data.

What the Hxll is this guy saying? If the subject answer was read correctly in two important and significant places it is clearly stated that "A hypothetical example could be:" 2nd paragraph, first sentence and "Remember, all of the above is hypothetical but illustrates the situation." 6th paragraph, 1st sentence. The key word is hypothetical.

Hypothetical | Definition of Hypothetical by Merriam-Webster

www.merriam-webster.com/dictionary/hypothetical Merriam‑WebsterSimple Definition of hypothetical. : involving or based on a suggested idea or theory : involving or based on a hypothesis. : not real : imagined as an example.

No, the examples are not misleading. They represent what happens. The situation does exist since it is "not real : imagined as an example". As you have clearly stated "and present a situation that would not exist", but that isn't necessary or required since the math formulas were correct but the figures used were hypothetical (not real : imagined as an example)

To use numbers that are actual, such as "14 AWG = 2.5 ohms per 1000 ft", or "12 AWG = 1.6 ohms per 1000 ft" or 117v or 234v would lose the clarity of the example, confuse the matter and the OP. The hypothetical example used is easier to understand and makes the answer to the hypothetical example clearer, not drowned in harder to understand mathematics.

You may want to restate you comments and figures. Since this was not intended to use actual values but to make the effects clearer, you may want to redo your values from actual to hypothetical. What would also be actually better and not hypothetical is that you change your OT back to the GA that someone else gave.

Einstein's Law of Relativity, E=mc², was hypothetical until proven.

Good Luck, Old Salt

All takes the same amount of energy.

Sorry if I fell into this category, just trying to provide some additional info.

No, your advice was great, I thought. Just being brief.

Remember, I just have one opinion, not always correct.

I've ranted before about our inability to agree on seemingly cut and dried subjects. It never does any good.

Reminds me of the guy who asked an engineer what time it was and and the engineer told him how to build a watch.

We really need to stop reading more into a question posed by an OP. The OP in this thread asked...

"Is 220V Baseboard Heater More Efficient Than 120V".

He did not ask if a 240V power system delivered electrical energy to a load in a manner more efficient than a 120V one did.

So... when you remove any consideration on everything OTHER than what he asked...

The answer is NO... a 240V heater is not any more efficient than a 120V one.

Someone got their feelings hurt over your suggestion. They're a poor sport for voting you OT.

I'm with you. If the OP was an electrical wizard, they would never have come here for such simple advice.

But as usual far too much meaningless information is forced upon the unsuspecting guy who just wants to know if there is any advantage to going to a 240V heater.

I agree with all your comments in your post, especially:-

"If the OP was an electrical wizard, they would never have come here for such simple advice."

Which is why the question should be answered AND safety information, although maybe unasked for, should be also mentioned.

It still amazes me that (gleaned from these CR4 pages at least) seemingly so little attention is paid in so many countries to the importance of following code and using and installing safely any electrical equipment...here is a prime example....

...said the man recommending thinner insulation and five-pinned power whatchamajiggers...

Incredible...just incredible

Globalspec must be so proud to count you in their midst.

A reasonable answer for a change, and by the way, I am sure they are!

Why did you post previously such obvious rubbish about someone online for anyone here to see, whiskey? or maybe whisky?

Stuff so easily proven to be wrong!!!

Please note that I am asking, not suggesting!!! (JIC!) There has to be a reason SURELY!!! Or were you just sucking up to Lyn? Buddy Buddies?

Me I love both types of whisky!!! But not enough to make me post such inaccuracies.....I could not afford so much!!!

Remember, I almost never post without researching first....nobody has to, its a personal choice.

Here are some more capitals for you to count:-

IF YOU DON'T PICK ON ME AND/OR MAKE STUPID COMMENTS ABOUT THINGS YOU DON'T UNDERSTAND, THEN I WON'T MAKE FUN OF YOU. NOR WILL ANYONE ELSE HERE.....

JUST IGNORE ME IF YOU CANNOT BE FRIENDLY, OR TAKE THE CONSEQUENCES.

Understood?

I wish you a great day.

You are an idiot.

That was a REALLY interesting comment Homer!!!

Its great to have something to amuse us all!!!!

Thanks for that......

De nada

You are welcome too.....

One thing you're all forgetting with 120V. For a new branch circuit an AFCI is needed therefore it's unlikely to work at all. Zero power consumption = 100% efficiency.

NEC-2014 210.12(2)

Why?

The 2014 code mandates AFCI protection in designated areas of dwelling units and dormitories... that's why.

I could have suggested a combined AFCI/GFCI (AKA DFCI)

The heater would be even safer, cold, but safe.

I am interested in why you post tat it would be cold, if everything is correctly installed? (Unless nobody switched it on maybe?)

There are combined RCD and over current" breakers available in most countries that I know of, which I personally (US code does not it would seem need one for "dry" areas!) would strongly recommend.

But not just for this heater, but for the whole electrical system in a house. Where I need here 3 of them, the UK and USA would usually only need one.....

Having painfully "tested" one many years ago, I can only recommend safeguarding the whole family, including pets that chew mains leads....they work and do drop the power very rapidly!!

But since then, I only test using the test button on the breaker itself, far less painful!!

Thanks for your post and any answer you can give me/us!!

Andy, look up what a AFCI is

Wiki (is American I believe) mentions for the device I am talking about always links to "RCD".....try it out.

So I would surmise that Wiki feels its the "best" name to use......

But I tried to learn more from your post, but this is what happens....check it out yourself!!

If you key "AFCI" into Wiki, you get the following:-

AFCI

From Wikipedia, the free encyclopedia

AFCI may refer to:

• Association of Film Commissioners International
• Advanced Fuel Cycle Initiative
• Arc-fault circuit interrupter

If you click on the lower one which might refer to what I was mentioning, it brings up the following:-

An Arc Fault Circuit Interrupter (AFCI) is a type of duplex receptacle or circuit breaker that breaks the circuit when it detects a dangerous electrical arc, in order to prevent electrical fires. An AFCI distinguishes between a harmless arc that occurs incidental to normal operation of switches, plugs and brushed motors and an undesirable arc that can occur, for example, in a lamp cord that has a broken conductor in the cord.

AFCI breakers have been required for circuits feeding electrical outlets in bedrooms of homes by the electrical codes of Canada and the United States since the beginning of the 21st century; since 2014, U.S. code has required them for outlets in most rooms in houses.

Arc faults in a home are one of the leading causes for electrical wiring fires. Each year in the United States, over 40,000 fires are attributed to home electrical wiring. These fires result in over 350 deaths and over 1,400 injuries each year.

Good to have for anywhere, I did not actually know much about them before, but only required for bedrooms in the USA & Canada, also, not really doing the job of an RCD as I expected....

If I key in DFCI instead, it links me to the "Dana-Farber Cancer Institute", which I am not really interested in.....

Using GFCI links instantly to RCD!!! Try it........ So I am correct, its the right name for the device I mentioned!!

Also, please explain what I am supposed to be learning from your post, which was:-

I could have suggested a combined AFCI/GFCI (AKA DFCI)

The heater would be even safer, cold, but safe.

Many thanks, but I really still don't get it...... Why is it cold????

The parts I am recommending would have allowed it to work and would have also done a good job of protecting anyone that touches it......from an electrical fault of course....

I am always willing to learn from anyone who really knows more than I do....so waiting on an explanation, thanks.

As I read it, only "wet" areas and a normal living room might not be considered a "wet" area.....

To me personally, this demonstrates a "hole" in the code if true (and I do believe you!).

Thanks for posting.

Read it again.

AFCI breakers have been required for circuits feeding electrical outlets in bedrooms of homes by the electrical codes of Canada and the United States since the beginning of the 21st century; since 2014, U.S. code has required them for outlets in most rooms in houses.

So ONLY in bedrooms...........unbelievable.........but nothing to do with earth faults via a human or pet for example, only to do with Arc Faults. Great to have in case of fires.....no question.

See here:-

http://www.afcisafety.org/qa.html

A good thing to have, but unless combined with an RCD (which is possible), does not prevent mains shocks to people and pets on its own.

People do not only get shocked just in bedrooms with no arc (and its not always for "electrical" reasons either!) but EVERYWHERE in a house, garage and garden.

.......pets do not only chew cables in bedrooms surely.....or have they been trained to know which room they are "allowed" to chew electrical cables in....?

So I am sceptical!!

Have an intelligent person read the code to you.

You posted:- Have an intelligent person read the code to you.

That must mean anyone but you!!

Especially as you are so well known here for Anon posts......

Pathetic is the only word that comes to mind.

Why not show, by quoting the relevant passage concerned?

The one that I have myself not found. That maybe(?) shows you are not quite as dumb as you appear to be!!!

OH!! YOU DON'T KNOW WHERE SUCH A PASSAGE IS EITHER!!!

Tee-hee...you got Andy to go all-caps...!

You also cannot count, or do not know the meaning of "ALL"!!

Here for you:-

TOTALLY SHOT DOWN TWICE TODAY BY ME!!

Count up how many caps there are in this post!!