Heating Hot Water.......

Nothing is really outside the realm of pellets. I want a pellet burning car. One out there getting 1.25 pounds to mile!

It would work, but would lose a lot of the "efficiency gains", you are using air as a medium of heat transfer (From stove to air from air to pump), and it is not a good one... There are many posts about electric water heaters being the most efficient / cheap way to heat domestic hot water.

Electric water heaters are 90-100% efficient, cheap, and have LOW stand-by losses. (If gas is cheap where you are, gas is usually even cheaper) Heat pump ones are nice, but they still take heat from the home... Nice in the summer.

Boilers have stand-by losses, which are the biggest problems with heating with oil/gas. If you are using a boiler to heat the home, then you have less stand by losses, making heating DHW(domestic hot water) cheaper.

Heat pumps are efficient, but if your taking hot air from inside, that you want inside...

I currently heat my water with oil too, and if pellets are all I need this winter for heat, I'll be plumbing in a electric water heater (Or 2 in serial if we need more hot water)

heat pump water heaters work great and they also condition the room that they are in. The initional cost is steep but they cost next to nothing to operate as long as they are not in a cold basement. If they are in a newer home in a finished room you probably wont even notice it on your electric bill.

LMPS said:

I believe this has been a topic before...how to best heat hot water if you are now using pellets as the main source for heating the house. Currently, I am heating the hot water with oil and burning 350 gallons a year which is 95% for hot water. Been researching alternatives and have been looking at heat pumps. I cam across this one www.nyle.com/water-heating and was wondering if anyone out there is using it in Maine or New England or some place that is on the colder side? Just wondering if it is working for you or not? Realize this is a little outside the pellet realm, apologize.

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Nyle Geyser heat pump water heaters have been discussed in the Green Room.
For example, see https://www.hearth.com/talk/threads/geyser-dhw-owners.88497/page-2

We have one and it works great. We use it 365 days per year and it saved 1 gall oil per day.
But it is in a fully underground basement that never gets below 55deg F.
Use it in parallel with the existing oil water heater, which is our backup if we get a house full of guests.

Our M55 Cast Insert does the majority of our heating now with the oil as very cold weather backup.

I am contemplating switching over to electric for DHW. I have a Boiler Mate that acts as a zone off of the boiler. We use in the range of 250-300 gallons/year to heat the water. Oil is now at $3.80/gallon in my area and this is putting a strain on the wallet, and it is only to heat water that is going down the drain.

Comparing Oil to Electric for heating water is hard to do because of the loss and inefficiencies of the oil furnace. With electric, the heating coil makes a direct thermal transfer to the water. No need to heat up a burn chamber and pipes before getting any heat to the water.

Electric DHW heater are anywhere from $300 to over $1k if you go with a heat pump assisted version. I think the key is getting one that has a very high "R" and "EF" value and a 20 year warranty.

Here is a good link that shows average annual operating cost of an electric DHW heater.

http://waterheatertimer.org/How-much-does-it-cost-to-run-water-heater.html

I would like to do electric to get away from oil completely but I bet I would need to upgrade to a 200 amp service. Something to think about if you consider going electric. Gas runs down the main road near me but not down my road...... bummer.

LMPS said:

I believe this has been a topic before...how to best heat hot water if you are now using pellets as the main source for heating the house. Currently, I am heating the hot water with oil and burning 350 gallons a year which is 95% for hot water. Been researching alternatives and have been looking at heat pumps. I cam across this one www.nyle.com/water-heating and was wondering if anyone out there is using it in Maine or New England or some place that is on the colder side? Just wondering if it is working for you or not? Realize this is a little outside the pellet realm, apologize.

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I am in the same boat as you on this issue and have wondered if an electric water heater is a better option. The problem is we have N-star here and the electric rates are high so I am not sure if I will save enough to make this worth doing. My options are oil, propane or electric none are inexpensive and propane would also add the cost of adding a tank etc. which I'd rather not do. Plus propane is much more dangerous than oil or electricity.

Ray

mepellet said:

I would like to do electric to get away from oil completely but I bet I would need to upgrade to a 200 amp service. Something to think about if you consider going electric. Gas runs down the main road near me but not down my road...... bummer.

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Most of the time you only need a 200 AMP service if you have electric heat. I live in 2 duplexes turned into one large home and i only have 1- 100 amp service supplying both sides along with electric water heater. No issues at all. Not to mention 3 ref and 1 deep freeze going and 7 people in the house.

I had a stiebel eltron accelera 300 installed this spring. Heat Pump Hot Water with 80 gallons of storage at 140 deg. With the mixing valve this means we have roughly 100 gal of hot water available on standby. Electric bill has not gone up at all yet (consistent between 50 - 65 / month) with AC running much of the summer. This winter will be the true test. My basement is unheated and stayed above 45 most of last winter. I insulated the rim and will put in new windows before the snow flies. My plan (hope) is that the basement draws heat from the ground and the heatpump turns that heat into hot water. So far the unit has been great. The fact that it removed moisture from the air is huge, basement has never been nicer, no musky smell. Was 3k installed. My boiler is off and available for vacations in the winter only, I'm saving about a gallon of oil / day. Payoff is estimated at 3 to 4 years. When the unit was installed I kept the coil in the boiler so in a pinch a valve can be thrown and the boiler restarted to make baseboard and / or domestic hot water.

Seasoned Oak said:

Most of the time you only need a 200 AMP service if you have electric heat. I live in 2 duplexes turned into one large home and i only have 1- 100 amp service supplying both sides along with electric water heater. No issues at all. Not to mention 3 ref and 1 deep freeze going and 7 people in the house.

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Great to know! Thanks!

mepellet said:

Great to know! Thanks!

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FYI: Typical electric water heater requires 30 Amp. 240 Volt power.. I like this tank: http://www.miniurl.com/s/22z


Ray

raybonz said:

FYI: Typical electric water heater requires 30 Amp. 240 Volt power.. I like this tank: http://www.miniurl.com/s/22z


Ray

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Sounds great in Summer But How do you deal with the cold air output in winter. seems like a draw,extract the heat from the air for your hot water and then replace the heat with your home heating appliance which may be electric as well.

Seasoned Oak said:

Sounds great in Summer But How do you deal with the cold air output in winter. seems like a draw,extract the heat from the air for your hot water and then replace the heat with your home heating appliance which may be electric as well.

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My hot water lives in the cellar so it's a non-issue here.. Some people can get this for very low cost unfortunately I can't..

Ray

raybonz said:

My hot water lives in the cellar so it's a non-issue here.. Some people can get this for very low cost unfortunately I can't..

Ray

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My HWH is in the same room as my furnace as is common.

raybonz said:

FYI: Typical electric water heater requires 30 Amp. 240 Volt power.. I like this tank: http://www.miniurl.com/s/22z


Ray

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Thats not a normal electric water heater though. I was questioning electrical capacity with a 100 amp service and a normal electric water heater.

Seasoned Oak said:

My HWH is in the same room as my furnace as is common.

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My hot water comes from the oil furnace via tankless coil.. It's cold in the cellar with a woodstove in the LR.. You should save $$ with this tank.

Ray

mepellet said:

Thats not a normal electric water heater though. I was questioning electrical capacity with a 100 amp service and a normal electric water heater.

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Same power requirements as reg. tank and 100 amp service should be OK unless you have lots of AC's..

Ray

Some simple math................

I use ~300 gallons/year to heat my DHW. So.....
(300/12)*3.80 = $95.00 per month

So if I were to say that the oil DHW heater is 80% efficient, then $76.00 is what is actually used to heat the water.

$76.00/$0.1487 per KW/h = 511KWh/year. This is close, but a bit higher then the average usage charts that I have found online.

Putting it on a timer so that it does not heat the water during the night may reduce the cost a little bit more. The electric bill for my entire house is ~$100/per month now without an electric DHW heater. That include 2 fridges, a chest freezer, well pump and water system.

I found a web page that shows an EF of 0.55 for an oil fired DHW system. So if this is correct then I should make an adjustment to the math in my last post.

$95.00 * 0.55EF = $52.25. This is now getting much closer to what I am finding on line in regards to operating cost of an electric DHW heater.

BradH70 said:

I found a web page that shows an EF of 0.55 for an oil fired DHW system. So if this is correct then I should make an adjustment to the math in my last post.

$95.00 * 0.55EF = $52.25. This is now getting much closer to what I am finding on line in regards to operating cost of an electric DHW heater.

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Interesting.. Sounds like the GE Hybrid could pay for itself fairly quick..

Ray

raybonz said:

Interesting.. Sounds like the GE Hybrid could pay for itself fairly quick..

Ray

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I was thinking that as well. My basement stays at a pretty constant 55* year around. This is on the upper end of the temp range requirements for a hybrid, but I think that the consistency in ambient temp would be a good thing. It would also dehumidify the basement in the summer.

BradH70 said:

I was thinking that as well. My basement stays at a pretty constant 55* year around. This is on the upper end of the temp range requirements for a hybrid, but I think that the consistency in ambient temp would be a good thing. It would also dehumidify the basement in the summer.

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My cellar does get muggy in the summer and warm as well.. Thinking the cost to heat water in the warm weather could be substantially less.. Tankless coils aren't efficient if you aren't heating with the boiler which I haven't been plus boiler maintenance would be reduced as well.. Personally I would like this water heater in my cellar especially if I could get some sort of rebate but I don't think I qualify because this is not a new home and I am upgrading from oil..

Ray

mepellet said:

I would like to do electric to get away from oil completely but I bet I would need to upgrade to a 200 amp service. Something to think about if you consider going electric. Gas runs down the main road near me but not down my road...... bummer.

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I too want to get off oil for my DHW. I will - for now - keep the oil burner which fires my steam heat system, for days when it is just too cold for my pellet stove to keep the entire house warm. I am lucky to have gas service in the house already. So my choices for DHW are oil, gas or electric. Then I have to look at a traditional hot water heater versus one of the newer on demand systems.

Anybody have some advice?