[majorvices]

Re: Tank vs tankless. I have a tankless at my house now and I save over $600/year (at least) over the old tank water heater. That and as long as there is gas we can run hot water all day long. I can run the dishwasher and take a shower and still get hot water from the sink. It's awesome!

[bo]

I have a small electric tankless where I brew, but it only raises the temperature of the water about 50-60 degrees above the input. I still like it and wouldn't trade it for the tank type. It only takes up about the space of a phone book and hangs under the sink in basically unused space. I just use it for washing and have others ways to heat sparge water.

I'd like to have one for the house, but it would have to be electric in my case.

[tubercle]

The only thing steam powered worth having is an Aeroplane.
http://www.youtube.com/watch?v=rN0iOkMNZqQ
 

You know that John Harford was into the steam powered stern wheelers?  He thought those were worth preserving.  

edit - It was a good album.  He looked a little different than in the video.
http://www.bluegrassjournal.com/2008/03/13/bluegrass-classics-aereo-plain-john-hartford/

 He was a certified Mississippi river steam boat pilot.

[tschmidlin]

Re: Tank vs tankless. I have a tankless at my house now and I save over $600/year (at least) over the old tank water heater. That and as long as there is gas we can run hot water all day long. I can run the dishwasher and take a shower and still get hot water from the sink. It's awesome!

Are you accounting for the extra water that you use with a tankless?  (Due to the longer time to get hot water from the heater to the tap).  It may or may not be a lot depending on usage, but it's not zero.

If I thought I could save $600 per year with a tankless heater I'd get one installed.  It's hard to run the numbers, the biggest gas charge by far is our heating.  The last monthly bill before we turned the heat on, the gas part was just under $32, and that includes cooking.  I know it will take more to keep the water hot during the winter because the garage is colder, but I still don't see $600 there.  Tank water heaters are becoming more efficient, so the fuel savings might not be as much.

I'm really not trying to argue against tankless, I'm just trying to point out some of the things that need to be considered for different applications.  It's not a one size fits all solution.

Oh, and I can run the dishwasher and take a shower too, and still get hot water from the sink.  Maybe the real problem was your old heater was inefficient and under sized.

[bo]

How do you figure you use extra water with tankless? If it was mounted where the tank the line lengths would be the same.

Actually if you have several tankless units mounted throughout the house, you lose a lot less water, because the runs are shorter.

[tschmidlin]

How do you figure you use extra water with tankless? If it was mounted where the tank the line lengths would be the same.

Actually if you have several tankless units mounted throughout the house, you lose a lot less water, because the runs are shorter.

It's not just about the line length, it is the time it takes for the water to heat up and get to the tap.  Unless the technology has changed from when my mom had one installed 15-20 years ago, it always took longer for the water at the tap to get hot than when it was a tank, and the tankless was closer.  This was because the tankless doesn't store any hot water, so when you turn the hot water on at the tap, the tankless has to fire up and start heating the water that is being delivered, meanwhile water is flowing down the drain.

I'm not sure I'm explaining this well.  I think of it this way - with a tank, you turn on the hot water and wait for the hot water to get from the tank to the tap.  With tankless, you turn on the hot water and wait for the gas to turn on, heat up water, and for the hot water to get from the tankless to the tap.  That's how my mom's worked anyway.

[bo]

How do you figure you use extra water with tankless? If it was mounted where the tank the line lengths would be the same.

Actually if you have several tankless units mounted throughout the house, you lose a lot less water, because the runs are shorter.

It's not just about the line length, it is the time it takes for the water to heat up and get to the tap.  Unless the technology has changed from when my mom had one installed 15-20 years ago, it always took longer for the water at the tap to get hot than when it was a tank, and the tankless was closer.  This was because the tankless doesn't store any hot water, so when you turn the hot water on at the tap, the tankless has to fire up and start heating the water that is being delivered, meanwhile water is flowing down the drain.

I'm not sure I'm explaining this well.  I think of it this way - with a tank, you turn on the hot water and wait for the hot water to get from the tank to the tap.  With tankless, you turn on the hot water and wait for the gas to turn on, heat up water, and for the hot water to get from the tankless to the tap.  That's how my mom's worked anyway.

My tankless is instantaneous, except for the delay in the line travel. This thing is about 7500W and the Ni-chrome heating wire is right in the water. If the tank was mounted under the sink, which it can't be, then it would be as fast.

[majorvices]

Unless the technology has changed from when my mom had one installed 15-20 years ago, it always took longer for the water at the tap to get hot than when it was a tank, and the tankless was closer.

Yeah, I can;t imagine the technology has changed over the last 20 years. That would be crazyness!  There is a short delay on mine at home but it's not so long that it becomes an inconvenience. I think the amount of energy you save far-far-far-FAR out weighs the amount of water you waste.

Like I said, the gas is much mroe efficient so if you don't have access to gas you might need to wait another 20 years for the electric to catch up. 

[euge]

My fairly new and efficient gas water heater is less than 8' from the kitchen sink. Despite that it would take over 20 seconds for the water to get hot. I measured the output and it was something like 2-3 gallons of water down the drain. So I installed an Ariston 2.5 gallon electric tank under the sink on series with the hot water tank. Now I get scalding hot water in about a second depending on ambient temp.

Would certainly get a tankless for any brewery I might build in the future. In fact if I were to build a house every bathroom or hot water faucet would have a point of use or tankless in series with the main tankless supply. That way you get nearly instant hot water wherever one is in the house.

As it is for the water to get hot in the master bath is several minutes even in the summer. Much worse in the winter. So I just place a five gallon bucket to catch the output and use it to flush the toilet.

I got my winter time usage down to under 2000 gallons.

[hopfenundmalz]

If Phil has the cheap electricity in France, and expensive natural gas, then it is clear to me which would have a cost savings.

If you live in an area where electricity is from the TVA, go electric.

In other parts of the country, natural gas might be the way to go.  Some people on car forums have said that electricity is so high  in the NYC area, that electric cars make no sense on a kilowatt per mile basis, let alone the depreciation to buy one.

[majorvices]

My fairly new and efficient gas water heater is less than 8' from the kitchen sink. Despite that it would take over 20 seconds for the water to get hot. I measured the output and it was something like 2-3 gallons of water down the drain. So I installed an Ariston 2.5 gallon electric tank under the sink on series with the hot water tank. Now I get scalding hot water in about a second depending on ambient temp.

Would certainly get a tankless for any brewery I might build in the future. In fact if I were to build a house every bathroom or hot water faucet would have a point of use or tankless in series with the main tankless supply. That way you get nearly instant hot water wherever one is in the house.

As it is for the water to get hot in the master bath is several minutes even in the summer. Much worse in the winter. So I just place a five gallon bucket to catch the output and use it to flush the toilet.

I got my winter time usage down to under 2000 gallons.

I just measured mine, slightly more than 1/2 gallon. The HWH is in the garage about 20 feet away. Do you have gas or electric? What brand? We have a Rinnai both here and at the brewery.

[bo]

I just realized that you guys are talking gas and mine is electric. There would be a slight delay with gas.

[tschmidlin]

Unless the technology has changed from when my mom had one installed 15-20 years ago, it always took longer for the water at the tap to get hot than when it was a tank, and the tankless was closer.

Yeah, I can;t imagine the technology has changed over the last 20 years. That would be crazyness!  There is a short delay on mine at home but it's not so long that it becomes an inconvenience. I think the amount of energy you save far-far-far-FAR out weighs the amount of water you waste.

I wasn't suggesting the water costs more, but it cuts into your actual savings.  It sounds like your costs will be small.  Like I said, "It may or may not be a lot depending on usage, but it's not zero."

So how has the technology changed?  Yeah, it could have changed in 20 years, but it was pretty straightforward at the time and doesn't seem too different to me.

[majorvices]

All I can tell ya is the Rinnai tankless water heater I have has cut my gas usage down at least 1/2. I used to get my tank filled 3-4 times a year. now it is 1.5 - 2 times a year.

I am sure the technology has improved over the last 20 years. I mean .. come on bro. Seriously? It has to have changed. Or more likely improved.

[tschmidlin]

All I can tell ya is the Rinnai tankless water heater I have has cut my gas usage down at least 1/2. I used to get my tank filled 3-4 times a year. now it is 1.5 - 2 times a year.

I think that's awesome - I'm not doubting you, ours just doesn't seem to take that much gas.  Under the right circumstances I'm sure tankless is the way to go, and it definitely sounds like it works for you.

I am sure the technology has improved over the last 20 years. I mean .. come on bro. Seriously? It has to have changed. Or more likely improved.

Why does it have to have?  Toasters don't seem to have changed much in the last 20 years.  Maybe it did, I don't know, I just don't think we can assume it did.

Anyway, I found a calculator for tankless vs. tanks, and based on the data I gave it (zip code and age of my water heater) it said I'll save at most $187 per year.  But if I replace my existing tank with one of the new ones that are more efficient, the savings drops to at most $15 per year.  That would take a lot of years to make up the additional cost.  Worse, depending on the unit I select the tankless actually costs more ($23) per year.

Anyway, it all goes back to doing your homework and making an informed decision.

Here's the calculator I used:
http://www.rinnai.us/tankless-water-heater-energy-savings-calculator/