 DraimanLet me see those devil horns in the sky
join:2012-06-01
Kill Devil Hills, NC
 ·Verizon FiOS
| reply to onebadmofo
Re: Low water pressure Even tankless isn't that great. I ended up having to add a 50 gallon tank as storage to the tankless system to handle peak demand.
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 onebadmofoRepost These Nuts In Your Mouth.Premium
join:2002-03-30
Reading, PA
kudos:1 | said by Draiman:Even tankless isn't that great. I ended up having to add a 50 gallon tank as storage to the tankless system to handle peak demand. What would you consider peak demand?
cause it's only me and my wife that live here. We have a dish washer that's used once a week. And a Washing machine that's used once a week as well.
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DraimanLet me see those devil horns in the sky
join:2012-06-01
Kill Devil Hills, NC Reviews:
·Verizon FiOS
| said by onebadmofo:said by Draiman:Even tankless isn't that great. I ended up having to add a 50 gallon tank as storage to the tankless system to handle peak demand. What would you consider peak demand? cause it's only me and my wife that live here. We have a dish washer that's used once a week. And a Washing machine that's used once a week as well. It all depends on the volume of hot water you use. That's affected by how much water the faucets, shower heads, etc. use aka gpm or gallons per minute. A shower head can use anywhere between 1.5 to 5.5 gpm's. If you have 2 showers going with 1.5's you're only using 3 gpm's but if you have 2 showers going with 5.5 gpm heads your using 11 gpm's! Normally a tankless will have a gpm rating. You might pick a lower rated gpm unit since there is only 2 of you but if you sell the house the next owners might have kids so they need to install a water heater as a storage tank to augment the tankless system. It's hard to say without a complete picture.
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What we're saying today is that you're either part of the solution or you're part of the problem. - E. Cleaver 1968 |
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 cdruGo ColtsPremium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7 | reply to onebadmofo
You don't happen to have a water tank on your roof, do you? |
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onebadmofoRepost These Nuts In Your Mouth.Premium
join:2002-03-30
Reading, PA
kudos:1 | 
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onebadmofoRepost These Nuts In Your Mouth.Premium
join:2002-03-30
Reading, PA
kudos:1 | reply to onebadmofo
So I'm looking at this and it seems like it would work for me. But what do I know.
»www.homedepot.com/webapp/wcs/sto···WidgetID
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DraimanLet me see those devil horns in the sky
join:2012-06-01
Kill Devil Hills, NC Reviews:
·Verizon FiOS
| Did you look at the specs on that unit? It shows the gpm flow based on the unheated water temp. If your water is 40 degrees for example and you want 110 degree shower that's an increase/rise of 70 degrees so that unit can only sustain 1.59 gpm's at that rate. It means you need a low flow water saver shower head and nothing else can be running to get the proper water temp. That will vary based on the water temp so in the Summer you'll be much better off but in the Winter you'll peak it out easy.
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What we're saying today is that you're either part of the solution or you're part of the problem. - E. Cleaver 1968 |
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 tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8
 ·G4 Communications
·Fairpoint Commun..
 ·Hollis Hosting
| reply to onebadmofo
said by onebadmofo:So I'm looking at this and it seems like it would work for me.
You realize 18Kw is 75A at 240 volts and will barely produce enough hot water for one shower if your incoming water is already pretty warm.
By way of comparison tank type water heaters are typically 3800 or 5500 watts.
/tom |
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 shdesignsPowered By Infinite Improbabilty DrivePremium
join:2000-12-01
Stone Mountain, GA | reply to onebadmofo
If you have the power to feed it:
Amperage (amps) 75 A
Your old water heater was probably wired for 30-40 amps.
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BobAccount deleted
join:2012-07-22
New Jersey Reviews:
 ·Optimum Online
| reply to onebadmofo
Short answer: No it won't work.
It requires a 75 Amp 240 Volt supply, which requires pretty hefty wires, depending on the distance from your electric panel. Not to mention you may not have a big enough drop. And in the winter will only provide 1.6 gal/minute of hot water. |
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DraimanLet me see those devil horns in the sky
join:2012-06-01
Kill Devil Hills, NC Reviews:
·Verizon FiOS
| reply to onebadmofo
If you really want to go that direction get the biggest unit you can. I mean if you want to spend $400 why not spend the extra $80 and be safe. You can't just return this type of item after a few months when you find out it's too small but on the other hand if it's too big it just doesn't have to work as hard making it last longer.
»www.homedepot.com/h_d1/N-25ecodZ···13h1QGSo
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What we're saying today is that you're either part of the solution or you're part of the problem. - E. Cleaver 1968 |
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BobAccount deleted
join:2012-07-22
New Jersey | 112 Amps! He'll need a new electric drop just for this! And it will barely provide enough hot water in the winter. |
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DraimanLet me see those devil horns in the sky
join:2012-06-01
Kill Devil Hills, NC Reviews:
·Verizon FiOS
| said by Bob:112 Amps! He'll need a new electric drop just for this! And it will barely provide enough hot water in the winter.
Yea it's crazy but if that's the path he wants to go down it's not much more work to do 112A vs 75A. He'd need at least 200A service for either.
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What we're saying today is that you're either part of the solution or you're part of the problem. - E. Cleaver 1968 |
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BobAccount deleted
join:2012-07-22
New Jersey | And all to NOT save money! |
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Reviews:
·RoadRunner Cable
 ·ViaTalk
| reply to onebadmofo
Maybe he should look into heat pump type water heaters. At least with them he shouldn't have to miss with new electric lines.
Think they qualify for rebates to cut down on the high cost.
»www.geappliances.com/heat-pump-h···-heater/ |
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DraimanLet me see those devil horns in the sky
join:2012-06-01
Kill Devil Hills, NC Reviews:
·Verizon FiOS
| reply to onebadmofo
This is the model I'd suggest to anyone needing electric heat.
»www.lowes.com/pd_386797-83-GEH50···cetInfo=
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What we're saying today is that you're either part of the solution or you're part of the problem. - E. Cleaver 1968 |
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BobAccount deleted
join:2012-07-22
New Jersey | Does GE even make water heaters, or are they still re-branded Rheems? |
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| reply to Draiman
Christ. My $400 dollar water heater works just fine. |
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tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8 Reviews:
·G4 Communications
·Fairpoint Commun..
·Hollis Hosting
| reply to Bob
said by Bob:Does GE even make water heaters, or are they still re-branded Rheems?
I think the GE heat exchanger water heater is their own design. But I assume they stick it on top of some customized off the shelf tank, but I'm guessing. The reviews I've seen have been mixed. They are very expensive compared to traditional electric heater. This has to be amortized over a relatively short time frame. The analysis I've read indicates the control setpoints are optimized for scoring high on the Energy Star test but may not be optimum for real life use.
Back to the OP to help understand the tradeoff of tank vs tanksless water heaters.
Efficiency for electrically heated appliance is 100%, all of the electrical energy is converted to heat. In a traditional electric heater we then need to look at heat loss through the tank. Given high performance foam insulation very little heat is lost during standby. In the summer losses increase temperate near the heater and if the space is air conditioned must be removed by the HVAC system. HVAC operate at greater then 100% efficiency so it costs less then a BTU to remove every BTU lost by the heater.
In the winter the effect is the opposite. Any heat lost by the heater reduces need to add heat by the heating system. Unless the house is heated electrically the cost of a heating BTU is less then the cost of an electric BTU but it does offset heating cost to some extent.
If you go with the GE heat exchanger unit when the heat exchanger is operating it is pulling heat out of the air and transferring it to the water. The efficiency of this transfer is greater then 100% because the system is simply moving heat around not making it. So in the summer it will reduce air conditioning energy cost because it is removing heat from the air and transferring it to the water. Keep in mind that this is offset to some extend because waste heat from the compressor and fan is dumping some heat back into the conditioned space. In the winter heat transferred from the air to water will have to be made up by the heating system. Since those BTUs are probably cheaper then electricity cost is reduced but every BTU transferred to the water needs to be made up by the heating system.
The GE heat exchanger unit may make sense in the south where AC is needed all the time, but I doubt it makes sense anywhere else. There is also the issue of maintenance and repair. I hate to poo-poo green technology but if it breaks who are you going to find with the skills to fix it.
A much simpler approach would be to capture waste heat from the Air Conditioner and use it to warm water in a preheat tank, then plumb that to a conventional water heater and use electricity to top it up as needed.
/Tom |
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onebadmofoRepost These Nuts In Your Mouth.Premium
join:2002-03-30
Reading, PA
kudos:1 | reply to Draiman
said by Draiman:Did you look at the specs on that unit? It shows the gpm flow based on the unheated water temp. If your water is 40 degrees for example and you want 110 degree shower that's an increase/rise of 70 degrees so that unit can only sustain 1.59 gpm's at that rate. It means you need a low flow water saver shower head and nothing else can be running to get the proper water temp. That will vary based on the water temp so in the Summer you'll be much better off but in the Winter you'll peak it out easy. I did but...based on the replies (which are actually helpful) it's quite obvious I have no clue about what is a good replacement.
It's seems like a lot to figure in. this is all new to me.
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