Gas water heater capacity

Yes, they are. The greater the mass the more heat to be stored and the more heat given off during the down times. What you need to know is how often and how long the burner runs just to maintain the heat level. As I said, if that "lost" heat from the tank is helping to heat your house, there is no additional cost during heating season.

If you do downsize, under your circumstances even a 30 gallon would be OK. That is really a lot of hot water for showers or even a batch of laundry, especially since most can be done in cold water these days.

Reply to
Edwin Pawlowski
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As pointed out the cost of the slightly less heat leaking from the surface area of a 40 gallon tank as compared to that leaking from the surface pf a 50 gallon tank would be minimal.

Also that heat, if you heat your house during say the winter or longer (depending where you live) merely means that your furnace or other heating devices would operate slightly longer to make up for the heat 'not' coming from the hot water tank.

Personally thinking the the difference will be so slight that the most economical plan is just to slap in another heater with exactly the same dimensions and plumbing hook-ups.

Also as pointed out the cost of hot water is not, usually, one of the major ongoing household costs. Unless you consider that cost of gas will increase drastically?

Intensive discussion about the difference in cost of the amount of heat leaking (into the house itself) from keeping the difference of 10 gallons of hot water at a certain temperature seem rather pointless. Presumably the water heater/tank is insulated???

What we do is leave warm shower water and the occasional hot bath to cool down warming the air etc. in the bath room before drainuing it away. Of course because of moisture we run the bathroom fan while doing that which 'wastes' some warmed air to outside.

If you are really agonising about the overall cost of hot water and your hot water use is low; look at the cost of electricity versus gas in your area and the costs of installing a cheaper and smaller electric hot water heater. There will also be plumbing costs if you can't do it yourself. And then get rid of the gas connection, chimney or flue vent completely.

This discussion is getting far too complicated.

Reply to
terry

It's nice to hear that you are well satisfied with tankless hot water heaters.

There is another do it your self group that frequently has questions and complaints about them but it also criticises and decries our North American practice of having a hot water storage tank either heated, electrically, by gas or from a heating furnace.

230 x 25 amps =3D 5750 watts. And they only use electricity while water is being used.

As pointed out you required 30 amp wiring; and 30 amp double pole circuit breakers to connect them. That's only 10 AWG IIRC. Not hard to do usually; but occasionally requires 'bunching up' things electrically in the main circut breaker panel?

Reply to
terry

And that is going to supply hot water in sufficient quantity to do exactly what? He's got one tank type now that supplies his entire house. With typical incoming water temps in winter in most parts of the US, 5750watts isn't going to supply enough hot water for even a decent shower.

Which is why you rarely, if ever, see an electric tankless used as a whole house solution. If you have gas available, then it's another story.

Another questionable notion is the idea that the heat loss from a water heater is less important because it goes to help heat the house in winter. I think in general, this is simply false. First, much of the heat loss in a gas heater is up the flue. Second, the heat that escapes the insulated surfaces of the tank, would go entirely toward helping heat the house, IF the tank were in the living space. Don't know about you, but I rarely see water heaters sitting in the kitchen. Usually, they are in the basement or garage. Let's say it's in an unfinished basement area, close to an outside wall as they are usually installed. I'd venture that the amount of the escaping heat that makes any impact on the energy usage of the house is tiny compared with the heat that is lost in the basement to the surrounding walls, etc.

And even if the tank was in the living space, somehow the fact that this heat is working against you when you have AC running never gets mentioned.

In short, to the OP, from your water usage situation, I see nothing wrong with going with a 40 gal unit. That is a very popular size for homes without the need for large amounts of hot water. Many homes have them and are not running out of hot water. Besides the initial cost being less, whatever you save on your energy, every little bit helps.

Reply to
trader4

I guess you dont get out much trader. Electric tankless are quite common even in cold climates. Here is just one of them:

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up all the tankless manufacturers. They all carry electric. Bubba

Reply to
Bubba

Something definitely out of whack if a 40 g doesn't cut it for only three. Raised four kids and wouldn't be able to think of time it was an issue...

--

Reply to
dpb

Probably. I just checked and we have a 40G gas unit. House of 3. We do have to time our showers/tub baths a bit but it is not hard. The dishwasher has to be accomodated for as well. Nominally need about 20 mins between bath/shower/dishwasher uses.

40G is plenty for one person. Ok for 3 with a little timing.
Reply to
cshenk

"RepairNovice" wrote

Ah, having rented before to others, this may be an agent issue vice owner? Do you have contact with the owner?

Although I would have been happy to get emails from my renters if there was an issue, they never availed themselves of that option. I am unsure if the

40G tank was sufficient for their needs for example. There were 2 adults and 3 kids here. It's one thing to adjust a 20 min heat cycle with just 3 people and totally another with 5.

Odd. Something wrong and I bet the house owner wants to know this.

They cost about what tank types do but are supposed to be more efficient in actual heating if the house has a smaller hot water draw. I pay to keep the water hot for example, vice a fast 'heat on demand'.

Be sure to check with the owner if you want to convert. You may be required to 'retrovert' back before leaving as the sort you speak of is seldom useful when there are many people who need hot water. Savings seem to degrade to make them more expensive if you have alot of folks who need hot water.

Reply to
cshenk

"Edwin Pawlowski" wrote

In my case, the lost heat is totally a benefit. It helps heat the garage and several pipes there burst last year so we had to add a heater. We do not need to AC the garage in summer, but we have to heat it a bit in winter.

We figured out the change at last. The 'heat unit' was better insulated while we were gone and the house was rented. This meant less leach hat in the garage and resulted in a 800$ busted pipe repair last winter. I'm actually thinking the insulation is costing us more with comparison of a heater back there, than removal of the added insulation . Kinda like, 'remove in winter, put back in summer'.

Reply to
cshenk

Yes, and you are right. It's an older unit and was not maintained at *all* by the renters. I am pretty sure we are getting about 50% efficency out if it.

I dont expect anyone to really 'track' all any of our posts to add things up so I'll add I'm the one who was in Japan almost 7 years with house rented. I am pretty sure this unit was replaced while we were gone, about 6 years ago? I bet it has a coil problem of some sort.

We have to unpack the last of the boxes in the garage before we can just drain it and see what's up. Having only just repaired the 'sunroom' we have not yet repopulated all the stuff stored in the garage so this isnt an option to just drain it.

It is very possible the unit is about 7 years old now with zero maintenance. With regular maintenance, they nominally last 15 years. Not sure what you can expect with none at all though?

It is not impossible to think we might be getting about the efficency of a

20G unit just now? I only can see it is a 40G and a long shower (over 10 mins) means a reheat time of about 20.
Reply to
cshenk

On Sun 24 Aug 2008 09:59:55a, told us...

I remember back in the 1950s in Cleveland, a popular ad by the gas utility company was for an "AUI-40", which mean an automatic, underfired, insulated, 40-gallon tank. It seemed at the time that a 40-gallon tank was what most people had.

Years later, when I built a new home, we had an 80-gallon tank installed because we had to Jacuzzi tubs in the bathrooms.

Here in central Arizona where in now live, we have only a 30-gallon tank because the incoming water is never very cold, in fact, usually on the warm side, especially in summer. It's an electric tank.

Reply to
Wayne Boatwright

And I guess you failed simple math. The poster claimed:

"230 x 25 amps =3D 5750 watts. And they only use electricity while water " is being used."

To which I stated that 5750 watts isn't going to supply enough hot water for even a decent shower. From your own link, it takes 100 AMPS to get a 73 degree temp rise at 2.25 gallons a minute. At 50 AMPS, the lowest AMP heater in the chart, you get a whopping 36 degree temp rise at 2.25 gallons a minute. So, with incoming water of even

50 deg, you wind up with 86 deg heated water.

Do the math anyway you want, and as I stated, at 25 amps, you aren't going to run a shower, much less an entire house, which was what the OP was trying to do. The electric tankless, by the spec sheet you provided, are only claimed to be practical for the southern US with

80AMPS. For the rest of the US they need 100 to 150 amps.

Now, how many homes have an extra 100 to 150 amps available for a water heater? And would you advocate using an electric tankless to heat water when the OP has natural gas available, which in virtually all cases is going to be cheaper?

Just because manufacturers make them, don't mean they are popular. Maybe I overstated the case by saying you rarely, if ever, see them used. Let me restate it by saying in the vast majority of cases they are impractical compared to other readily available solutions. And here in NJ, I've seen lots of new homes recently. A few had tankless, but every one of them was nat gas tankless. I did not see a single electric tankless.

Electric tankless are quite

Reply to
trader4

Nice math you did there. So impressive. And YES, you did overstate your case like all you EE's do all the time. I didnt care what electric he has in his home. YOU said (and I quote)

**Which is why you rarely, if ever, see an electric tankless used as a whole house solution. ***

Obviously you live in a trailer or under a rock. The electric is becoming more and more popular. Its very apparent. When natural gas is cost is going through the roof with no end in site. Our area alone will go up 50% this winter in natural gas cost. Once again, you were WRONG! Say it trader, "You were wrong". You guys have such a hard time with that phrase. Bubba

them:

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> Look up all the tankless manufacturers. They all carry electric.

Reply to
Bubba

Sure, just ignore the math and that the typical service is 100-200 amps and that in most of the US, to have any reasonable output from an electric whole house on demand water heater is in excess of 100 AMPS. So what if the OP has to get a new higher amp service from the street, a new panel, pay for that installation cost, it doesn't come out of YOUR pocket, right?

YOU said (and I quote)

OK, I'd like to put it to a vote. Simple questions:

1 - How many people reading this newsgroup have an ELECTRIC WHOLE HOUSE WATER HEATER?

2 - How many believe they are a practical. cost effective solution for a whole house water heater in most single family homes in the US?

Reply to
trader4

I cant help it if you live in a trailer. Believe it or not there are a LOT of people out there with money. I install and service it for them everyday. How about a home with 7 GeoThermal systems! Yes, thats a home. It is commonplace. Boggles my mind everyday but its there, it happens and people have the money to pay for it..

Simple questions for a simple-minded simpleton. How is it you think that a couple people answering a newsgroup qualifies for an accurate accounting of the whole house electric on demand water heaters in your area, my area or the whole country? You really need to step away from the computer and go take a walk outside once in a while, trader. Bubba

Reply to
Bubba

pplies his entire

ng water of even

much electric power is generated by burning oil or natural gas, electric costs are going up, just a little delay..........

electric is generally accepted as costing more than natural gas, oil, and even coal.

Reply to
hallerb

electric tankless where incoming water is cold, like 40 degrees, and people want to run more than one shower at a time REQUIRES a dedicated

200 amp service just to heat water, seperate 200 or 100 amp service for all other uses.

this requires a large upgrade, utility company cooperation, very costly and more so where service line to homes are underground. the tankless companies themselves recommend putting 2 units in series for such applications......

sure it can be done if you dont mind spending boatloads of money:(

Reply to
hallerb

And that has exactly what to do with how practical or common it is to find whole house electric tankless water heaters?

I install and service it for them

Now you're really showing who's seriously out of touch. A home with 7 GeoThermal systems is common? LOL.

And this has what again to do with the thread? You claim to be in the trade. The OP stated the situation. He currently has a single

50 gal natural gas water heater in his single family home hat he needs to replace. He's considering moving down to a 40 gallon to save a bit. How many customers have you had in that situation that went to an electric tankless? And if there are any, please tell us how many amps and how it fit into the overall electric capacity of the house. And how much time would you spend scoping out and quoting a customer an electric tankless install in that situation?

I already gave you my answer. It may happen, but it's rare. And as I've stated, over the last couple years, I've looked at 100+ homes here in NJ, which I'd say is an average climate. I'd say 100+ homes is a decent sample size. About half of them were new construction. And since you dragged cost into it, they were all over $800K, about half were $1mil+. I saw maybe 2 that had tankless period. And not one of those was an electric tankless, for obvious reasons.

Pay attention. I didn't say it was an accurate accounting. But if indeed electric whole house tankless are as common in homes as you claim, we should hear from some folks. I see questions here all the time from folks using electic storage, gas storage, oil storage, gas tankless, etc. Can't recall anyone that actually has an electric whole house tankless. I recall people asking about them, but not anyone who actually has one. Not saying they don't exist, only that they are in fact not common. Afraid of a simple question?

Reply to
trader4

Wow! You are dense. It appears you dont live in an area where anyone has anything "above average". Your loss. You should get out once in a while.

Tell me where I said it is "common". Now it appears you cant read either. By the way, around here, lots of people have actual full size pools in their home. Not a pool in a screened in enclosure but in their basement. Ive got one that even has one on his roof. Some have basketball courts. Unfortunately, I dont have that kind of money but sure is neat to see how the other half live. Very nice customers too. They dont haggle over $100.

Because you cant seem to get it through your pea-brained head that other people live better than you. MUCH MUCH better. Your little postage stamp of the world is just a spec.

Hey, you finally got something right.

Of course it isnt an everyday occurance. But you made it out that it never happens. Again, you were wrong and you cant stand to admit it.

No actually what you said was:

***Which is why you rarely, if ever, see an electric tankless used as a whole house solution.**** You should learn to "Never say Never". It will always bite you in the ass.

and in this area, tankless is becoming more and more popular. I have people ripping out oil and gas furnaces and putting in heat pumps. Gas and oil is expensive here. Electric is too but not considered as bad.

Then it seems that your blithering is quite useless in fact.

and I see questions in here about people wanting to install window units in attics, crawl spaces, outhouses, etc. So exactly has that got to do with an accurate accounting of anything?

Afraid of a simple answer? Bubba

Reply to
Bubba

It's quoted right above for you. Here it is again,exactly what you posted:

"How about a home with 7 GeoThermal systems! Yes, thats a home. It is commonplace."

By the way, around here, lots of people have actual full size

And again, this has zippo to do with electric tankless water heaters.

I would say you can't get it through your head that living better has very little to do with electric tankless water heaters. Maybe that's on your dream list of things you want to have, but clearly not on most normal people's radar map.

Gee, a minute a go electric tankless was a common thing in a single family home. So were 7 geo themal systems.

But you made it out that it

Yes, and I corrected that in the very next post to "Let me restate it by saying in the vast majority of cases they are impractical compared to other readily available solutions. " Which I stand by.

You on the other hand, chose to go on the attack on me. You even had the gall to try to hurl insults because I did the simple math that showed the post that started all this discussion of electric tankless whole house was full of baloney. That poster went through an example suggesting a system using 25 amps, which any damn fool knows is off by on the order of 4 to 6 times. You let that go by the wayside, but jump on me, for pointing out the simple physics don't work out. That obviously is beyond your math level, which is why you feel the need to slam engineers.

And just for clarification, why don't you share exactly where that is?

Also, tankless is becoming more popular here too. Five years ago, instead of seeing 2, I would have seen zero. So, what? We were talking about the practicality of a 40 or 50 gallon natural gas storage tank in an existing single family home vs an ELECTRIC tankless. Got it now?

So, what should the OP do? He needs to replace a 50 gallon natural gas storage unit. He's considering going down to a 40. And you say, he should do exactly what? Put in an electric tankless? Simple question, in most cases like this is it practical and cost effective to put in an electric tankless for the whole single family house, yes or no?

Reply to
trader4

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