Hot water tanks vs. the new gadget that heats water quickly

[Sekretgardengal]

We were told to put in that new water heating thing. I think it's called a set??? It's a little box that the pipes run through and it heats the water as needed. This would save us a ton of money on the electric bill. We now have a hotwater tank. Does anybody know anything about this new way of heating water for the home?? Does it run by propane, electric, etc.?

[PDXnative]

Originally Posted by Sekretgardengal

We were told to put in that new water heating thing. I think it's called a set??? It's a little box that the pipes run through and it heats the water as needed. This would save us a ton of money on the electric bill. We now have a hotwater tank. Does anybody know anything about this new way of heating water for the home?? Does it run by propane, electric, etc.?

They are popular in Europe, but they can either save you money , or not save you money. It depends on how much water you are using and the overall cost of the units. They are not very cheap. I would talk to another pro in your area about it.

[Curious George]

Thought about that when I built my house I am sure they have improved since then .
But I didn’t want hot water lag, running the water till I got warm water .
Find someone who has one an try it.

[MyAzi]

I am curious to know what they are called. I have heard about them but often wondered how many years it would take to pay for it'self and start to save money.

[PDXnative]

Tankless water heater.

http://www.gotankless.com/

http://www.eere.energy.gov/consumer/.../mytopic=12820

[MyAzi]

okay so even the most expensive model...seems inexpensive as to what I was thinking. The only drawback I see is that for a family of 4... you might need 2. One for showers and sinks and one for appliances. We run the dishwasher 5-6 times a week... and between the 4 of us who live here we do maybe 6 or 7 loads of wash a week, a minimum of 28 showers a week... sometimes more and the boys love to linger FOREVER in the shower. So that would be cool to have because we can take back to back showers with out running out of hot water.

Might be worth it...

[the dufferz]

The payback on a installed tankless heater is pretty high, higher than 10 years, which has traditionally been considered a good break point for energy saving products.

The larger models will provide 7-8 gal. per minute of hot water. With a average showerhead using 3-5 gals per minute, this means that you have a two shower max (at the same time), or you can do the dishes and a shower with little to no problem. Clothes washing and shower would only be interesting if you used straight hot for the clothes washer.

The problems with the units are:

1. Placement. the tankless should go on an outside wall of the house. Many models are designed to actually be on the outside of the house. This typically means re-piping your water pipes.

2. Fuel quantity. If it is a natural gas tankless, there is a limit as to how much gas your meter can handle. This should be pretty standard throughout the US, so a typical meter can handle 300,000 Btu's of gas. The larger residential tankless will use around 200,000 Btu's. With a 60-70,000 Btu furnace, you would be fine, but if you also have gas cooking, fireplace, BBQ, Dryer... whatever, you can easily max out your meter. The result is a lack of gas, thus a lack of hot water at peak use.

For propane, just remember that at 200,000 Btu's, that will suck over 2 gals per hour of propane. Balanced with that, however, is that the good models do not use only 200,000 btu's when on. They adjust the burner based on the Gals. per min. and outgoing temp.

The question of energy savings is a hard one. The tankless is 20% higher efficient (60% for a tank, 80% for a tankless) so it should save you money... but wait. It's also possible to have what I call the "Costco" effect.

You go to Costco, Sam's club or any other bulk savings place. You get a GREAT deal on candy bars, so you buy the Mega Family Pack of 100. Normally you would only buy a pack of 10 at the regular store. For most people, the simple fact that you have 100 bars would make them consume more bars faster. In the end, you go through 100 bars in the same period of time that you would have only purchased 7 packs of 10. In the end, which did you spend more on?

If you have kids who now know that there is "endless" hot water (you see, I was good and only blamed the kids...not that any of us adults would do this), so they have this endless supply, so there is no need to get out before they run out... so in theory they may end up taking 20% longer showers, running up your water bill as well...

[the dufferz]

Originally Posted by Sekretgardengal

Does it run by propane, electric, etc.?

It typically runs by propane or natural gas. They have had electric one's out there, but they are typically poor performers and now are used as a "point of use" heat source (under sinks, for a single point of use like a bathroom)

Originally Posted by Curious George

Thought about that when I built my house I am sure they have improved since then .
But I didn’t want hot water lag, running the water till I got warm water .
Find someone who has one an try it.

CG, most of the high end models have a "high fire" setting which gives full power on startup. They are electronic ignition, so there would be a slight momentary hesitation, but not nearly as bad as in the "old" days. Where people get in trouble is the lack of high fire if their meter is maxed out. Then they don't get the water temp they want. Not good.

[PDXnative]

You also need to look at the absolute cost (flashback to Economics classes). You need to factor in the cost of the units, plus installation, plus plumbers cost, plus electricians costs(?), plus gas piping cost (if gas), plus any other costs associated with it and compare that to the cost of a standard water heater. It may be a better value to go with a high efficiency or even two high efficiency tank water heaters and insulate them and the pipes.

[MyAzi]

Thanks Duff... that puts a different spin on it... Endless hot showers... YIKES I don't know that the boys would ever get out... Even now as it is needed I turn on the washer to make the 14 year old think he is out of hot water, just so he will hurry!!!!

[the dufferz]

Originally Posted by PDXnative

You also need to look at the absolute cost (flashback to Economics classes). You need to factor in the cost of the units, plus installation, plus plumbers cost, plus electricians costs(?), plus gas piping cost (if gas), plus any other costs associated with it and compare that to the cost of a standard water heater. It may be a better value to go with a high efficiency or even two high efficiency tank water heaters and insulate them and the pipes.

Indeed, that is correct. A typical tankless system installed runs between $2,000-3,000. A regular water heater runs $400-$800.

Originally Posted by MyAzi

Thanks Duff... that puts a different spin on it... Endless hot showers... YIKES I don't know that the boys would ever get out... Even now as it is needed I turn on the washer to make the 14 year old think he is out of hot water, just so he will hurry!!!!

you really want to get him out fast? Go to the water heater and turn off the water valve that is above the tank. Instant cold water! (all it takes is once).

[MyAzi]

Originally Posted by the dufferz

you really want to get him out fast? Go to the water heater and turn off the water valve that is above the tank. Instant cold water! (all it takes is once).

now that is just plain mean!!!! Not sure I can be that mean!!!

[the dufferz]

Originally Posted by MyAzi

now that is just plain mean!!!! Not sure I can be that mean!!!

hey, it's only mean if he hears you laughing!

[Sekretgardengal]

I will have to let my husband read all this now. I don't know a thing about water heating. He will have to decide. I will go on and look at the links you posted for me. Thank you!

[Sekretgardengal]

I saw the prices of these units in Home Depot last week. Wow, they are around $1000.00 I thinks we will stay with the old fashioned hot water for now.

[the dufferz]

Originally Posted by Sekretgardengal

I saw the prices of these units in Home Depot last week. Wow, they are around $1000.00 I thinks we will stay with the old fashioned hot water for now.

Those are the cheap ones!

[Sekretgardengal]

Originally Posted by the dufferz

Those are the cheap ones!

wow, we will stay with the conventional one!

[catfish]

Originally Posted by Sekretgardengal

I will have to let my husband read all this now. I don't know a thing about water heating. He will have to decide. I will go on and look at the links you posted for me. Thank you!

A tank less water heater cost allot more to buy, Allot less to use, Look at tank less water heater in the web. We have one in the new house.

[catfish]

Originally Posted by Sekretgardengal

We were told to put in that new water heating thing. I think it's called a set??? It's a little box that the pipes run through and it heats the water as needed. This would save us a ton of money on the electric bill. We now have a hotwater tank. Does anybody know anything about this new way of heating water for the home?? Does it run by propane, electric, etc.?

You can get them to use propane natural gas or electric what ever your need is. Are heater is the Rinnai. See the links


Rinnai


Tankless Water Heater Buying Guide

[Wyoming53]

There are new houses going up behind my house. A developement that has installed "Tankless" in all the places. A friend bought one of the houses as it was being built so I was over visiting with him and we walked through a few times and he pointed out what they were putting in. He didn't like the idea of Tankless. He mentioned he'd probably have to replace that right after he moved in.

It's been 4 months now and I asked him the other day if he ever replaced the Tankless. He said no, it has done everything they've expected.

He's retired but she still works. So it's not like there's both bathrooms going at the same time. No real demand on the Tankless. But so far, they really like it. He didn't mention how his bill was cause that would be kind of a moot point. If he would have had a tank and then switched, he'd have something to compare it to.

[Wyody]

The idea is very appealing.
No standing water to keep re-heating whether you use it or not.
No standing water to rust the liner, dip-tube, etc.
You wouldn't believe how fast things decay here and in other places 53 ... well, I suppose you do but point is, rust and mold aren't common to the Rockies but here in Oregon, a 25yr water-heater lasting 10yrs is not so bad.
I've seen them on a small scale - running on gas and it runs straight through in one little tube - being heated quickly. Same general principal of the tubes in a solar panel - not so much water in the tube, heats fast.
Will be very interested to see some comparisons. I figure it's the wave of the future.
Fi'ty, do you, by any chance, have a copper tube wrapped around your wood-stove stack? That's an old trick others have used - works well for small amounts of hot water - like for dishes or simple wash-up.

[Wyoming53]

No Wyody, I sure don't. Wish I did, I know exactly what your talking about.

It was interesting, a few years back a friend had a place down in South Dakota. I was there for supper and noticed the heat kick on. But no noise. I asked him about it.

He had designed and got a patent on a heating system. It was located in the barn. Kind of a boiler system and then plumbed it to the house. Wood burning with a gas backup. Worked pretty good.

Originally Posted by Wyody

The idea is very appealing.
No standing water to keep re-heating whether you use it or not.
No standing water to rust the liner, dip-tube, etc.
You wouldn't believe how fast things decay here and in other places 53 ... well, I suppose you do but point is, rust and mold aren't common to the Rockies but here in Oregon, a 25yr water-heater lasting 10yrs is not so bad.
I've seen them on a small scale - running on gas and it runs straight through in one little tube - being heated quickly. Same general principal of the tubes in a solar panel - not so much water in the tube, heats fast.
Will be very interested to see some comparisons. I figure it's the wave of the future.
Fi'ty, do you, by any chance, have a copper tube wrapped around your wood-stove stack? That's an old trick others have used - works well for small amounts of hot water - like for dishes or simple wash-up.