# For non oil burners - how to get hot water



## wannabegreener (Jan 5, 2012)

I see a lot of posts about no oil delivery for years.  If you have oil, I would assume some of you used to use your oil fired boiler for hot water.  So my question is, if you are not using your boiler, how are you getting your hot water.

I have a jotul insert and have been using it for just about 1 complete season.  I ran out of dry wood last march and had to run the boiler and shut down the insert.  From last December to now, I have burned 580 gallons total.  I did some testing and I burn about .9 gallons a day in the summer for domestic hot water.  If I assume the same year round, that equals 330 gallons which means that I used 250 for heat.  I think I'm doing better this year for these reasons.

1 warmer outside.
2. I thought my wood was dry last year, but it is much drier this year so hotter fires.
3. I delayed my programmable thermostat to come on later in the morning which allows me to get the fire going.

I would really like to get the 330 gallons for hot water down, but don't have a clue how to do it.  I don't have natural gas (well not the kind you can hook up to a hot water tank), I don't have propane, and don't want to use electricity since it will be extremely expensive.

I have thought about solar, but have not looked into it that much.

The good news for me is that I was burning about 1100 gallons before I made some upgrades and had the insert put in.

Any suggestions would be great.

Sorry if this is the wrong forum.


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## Gary_602z (Jan 5, 2012)

What would an electric one cost to run? I haven't researched it but if it was 50.00 a month it probably would be cheaper than oil.

Gary


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## bogydave (Jan 5, 2012)

I plan on swapping out my hot water heater with a "On Demand" one.
I have NG but believe they make diesel ones also.
They only heat hot water as you use it, not heat & store & keep it hot until used. 
Quite a bit of energy savings with them.
Try "tankless hot water heaters" as a search, may need to refine to "oil fired".

Someone may move this thread to the Green Room, or DIY. But I've been wrong before.


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## buggyspapa (Jan 5, 2012)

heh, you're probably not going to like this response, especially if there are women in the house...i turn the oil burner on twice a week to shower and do dishes. otherwise it's cold washcloths and dishes piling up. i've been doing this in my current rental and a previous one for almost four years. no choice really, when i can't invest in an alternative that i can move with me easily. i at least have a woodstove currently that keeps the house around 60 when i'm not home to feed it. but i can't justify keeping that boiler going when there's no reason to have all that hot water ready all the time. one gets used to it. 

the on-demand heaters, common in europe but rare in the u.s. are a good bet, and there are good alternatives that come with tax breaks available. also better hot water heaters: Stiebel is one brand. something's gotta give. prepare to invest.


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## woodgeek (Jan 5, 2012)

You're in the right place....

(1) Electric tank: cheapest to install, maybe $400-$700/yr to operate.  Cost per unit of hot water is comparable to that of oil, but much lower standby loss and maintenance costs, so you will still come out ahead.

(2) HP water heater: search for 'geospring' and read threads. $1000-2000 more expensive up front than (1), and requires a large semi-conditioned space to operate in (i.e. an unfinished basement), but costs 50-60% less to operate per year, so has a lower ultimate cost than (1).  Makes more sense if you have high usage, AO Smith makes an 80 gallon version, geospring is 50 gallons.

Issues are: do you have enough elec in your breaker box?  Can you shut down your boiler for 6 mo/yr without concerns re leaking, rusting out, etc?  Many conventional boilers will leak/fail prematurely if left cold for long periods.


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## jebatty (Jan 5, 2012)

A few words I have repeated several times on electric hot water heaters. Conserve use, low flow everywhere, navy showers, no need to fill the tub full. Then, insulate: 6+" of fiberglass sides, top and bottom too, by building a frame under the hw htr. Insulate: all hw pipes, everywhere you can get to. Heat traps: large 12-18" heat traps on both the cold supply and hw pipes to prevent thermo-siphoning. Conservation aside (our water usage didn't change from before to after insulation), the insulation and heat traps cut our electric usage by 50% (electric on a separate meter in our house). Pay-off from less than a $100 one-time investment is huge.

Due to our off-peak electric for hw (electric only 11 pm to 7 am) and a rate of $0.04/kwh, monthly electric bill is less than $5. Yours may be more based on your rate and usage, but with some minimal effort electric by far can be the least expensive way to hot water.


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## Ehouse (Jan 5, 2012)

A small oil fired water heater may be cheaper than a boiler and indirect if you're not using the boiler for heating.

Ehouse


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## Highbeam (Jan 5, 2012)

Your biggest problem is that you think electric is too expensive. Using your numbers you are spending 100$ a month for oil hot water. Enter the electric tank water heater. You will not spend 100$ to heat water unless you have an exceptional consumption figure or your power cost is exceptional. 

Seriously, my whole power bill averages 100$ year round and I heat water, a huge hot tub, range, fridge, extra freezer, lights, etc. Power here is cheap at 10 cents per KwH

I don't believe that using a boiler system to heat water is ever going to be cost effective unless you already have the boiler running for home heat.


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## Seasoned Oak (Jan 6, 2012)

Electric water heaters are very efficient especially when turned to no more than 120 Degrees. WHere you dont need to mix cold with it for a shower.
WHen i do this i dont even notice a bump in my electric bill. OIL for Hot water NEVER.


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## wannabegreener (Jan 6, 2012)

Thanks everyone for the pointers.  I just assumed that the electric water heater would be too much to run.  I changed my boiler to a cold start boiler so shutting it down in the summer should be possible.  The oil fired boiler I put in uses a superstor for hot water.  My previous boiler had on demand but my water is very bad.  I have 4 filters trying to clean up the water but there it still cakes up the on demand so the heat didnt efficiently heat the water.  I was told that the inside of the on demand system kept getting caked up and didnt let the heat through to heat up the water. 

The new boiler saves me about 350 gallons per year and the insert seems to be saving me about 230 gallons.  

Turning on the boiler twice a week won't cut it at my house.  Nice thought though.

There is a possibility that I ca get a superstor for free and I was thinking of using it as a heat exchanger for solar.  I would have the heated water from the solar superstor feed the superstor connected to the boiler.

I currently have a mixing valve on the superstor.  I was told that the temp in the superstor needed to be x degrees to kill any bacteria (or something like that).  Then use the mixing valve so no one gets scalded.  Anyone know if that is true?  With 4 adults taking showers, and not navy showers, I have never run out of water.  Lowering the temp on the superstor coould be a good zero cost start if the water will still be bacteria free.  I think my mixing valve sets the water temp around 110. 

Any idea how I can determine what a water heater would cost me to run?  I'm in NH and I thought the cost of electrify was high here.  I just checked and it looks like psnh charges 17 cents per kilowatt.

I'll do more research.

Thanks for everyone's help.


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## wannabegreener (Jan 6, 2012)

Psnh reports that a 20 gallon water heater costs $77 per month.  Ouch


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## woodgeek (Jan 6, 2012)

On a BTU vs BTU basis, $0.175/kWh is the same as $6/gallon oil (assuming elec is 100% efficient, oil is 80%).  So, at that rate, elec water heating is almost 2x as expensive.  Of course, if you are burning a gallon on standby for every one you burn for DHW, its a wash.

A HP water heater would be cheaper to operate.


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## Seasoned Oak (Jan 6, 2012)

On city water they already have chlorine in it to kill the bacteria ,i suppose on a well you might need to worry about bacteria.


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## jebatty (Jan 6, 2012)

> Psnh reports that a 20 gallon water heater costs $77 per month.  Ouch



Ouch, indeed. We have a 51 and 40 gallon electric hot water heaters, insulated as indicated above, wife and I in the household plus guests, $5 month operating cost.


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## maverick06 (Jan 6, 2012)

i have a 60 gallon electric hot water heater. My wife/I/6 month old daughter in the house. 

The hot water heater is on a off-peak meter, it only runs about 12 hours a day. It costs about $0.09/kwh. for a monthly bill of about $20. We arent crazy about taking short showers either, just normal use. 

Inlet water temperature varies dramatically, from about low 60's to mid  to low 40's. January, the bill is usually around  $30, in june/july it is about $14. 

I like the heat pump hot water add-on units. However, for now, the return on investment isnt quick enough to justify the unit.  Its always good to make sure that you drain from time to time to get rid of material that has settled out/corrosion by products.


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## fordss (Jan 6, 2012)

I was using about a tank of oil a year just for hot water and decided that I was tired of spending around $1000 a year on oil for it so last year I installed a electric hot water heater and my electric bill went up around $16 a mth at a rate of about $.13 a kwh that's for 2 adults and one 3 year old.


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## Jags (Jan 6, 2012)

Go electric.  Insulate the heck out of it and the pipes.  Virtually maintenance free and highly reliable.  I have a 60 gallon that has NO problem with keeping up with me/her/23yr old girl and two little ones, washing machine and dish washer.  I have never run out of hot water.


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## Seasoned Oak (Jan 6, 2012)

fordss said:
			
		

> I was using about a tank of oil a year just for hot water and decided that I was tired of spending around $1000 a year on oil for it so last year I installed a electric hot water heater and my electric bill went up around $16 a mth at a rate of about $.13 a kwh that's for 2 adults and one 3 year old.



Sounds like my results as well but we have 5 people in the house. I have the temp set at about 120
The big drawback with oil is not only the price but your chimney starts drawing out the heat the minute your burner shuts down if you are using an oil boiler with a heat coil. Furnace has to cycle on many times a day just to maintain hot water even with no use at all.


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## billb3 (Jan 7, 2012)

I've just ripped out my oil furnace with hot water coil for the same reasons you cite. Too expensive.
Might have been doing almost a gallon a day for hot water, too.
No way you'll save money going electric.

I  put in a Buderus oil burner and a storage tank http://www.buderus.us/products/storagetanks/tankssolarsystems/logaluxsm300sm400.html with oil burner coil on the top and solar panel coil on the bottom.


If you cut back the temp on the mixing valve you'll be sucking a tiny bit less hot water out of the tank.


Guy down the street (with solar panels)had the same system but originally had a separate tank for the solar and it used more oil than a single tank. He now has a single tank with two coils.

My roof points south so I have a perfect roof and it is not shaded much but it is all oak trees so I'll probably make more hot water in Winter than Summer.


I have a chimney to remove and some roof repairs before the solar panels can go up.


My goal is to shut off the furnace when I no longer need heat in the Spring and not have to hear it run again until Fall.





I also went direct vent on the oil burner to get rid of the chimney - it sucks in air from outside the house and doesn't have the loud obnoxious fan a power vent has.


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## wannabegreener (Jan 7, 2012)

fordss said:
			
		

> I was using about a tank of oil a year just for hot water and decided that I was tired of spending around $1000 a year on oil for it so last year I installed a electric hot water heater and my electric bill went up around $16 a mth at a rate of about $.13 a kwh that's for 2 adults and one 3 year old.



How big is the HW tank?  It is me, wife, and two younger daughters.  Also, for those with electric HW, how quick is the recovery.  Mostly doesnt really matter because we all take showers at different times of the day, but curious when we have guests.

The superstor I have is 60 gal, I would think that the 20 gal would be small for a 4 bed room house.


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## Highbeam (Jan 7, 2012)

I propose that it won't cost any more to have a 60 gallon electric water heater than a 20 gallon electric water heater. They have the same electric demand, you are heating the same amount of water, what you get with the larger tank is more hot water consumption before running out. 

Your power is relatively cheap. Those who have made the switch report a minimal price increase to their electric bill. 

Using electric as a fuel has other benefits such as a pretty consistent price, a steady supply with no risk of some yahoo iranian causing an increase, no CO danger, no fire in the house, no noise, no chimney to leak water or heated room air. There's more but the most important thing is that it will be cheaper.


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## woodgeek (Jan 7, 2012)

I agree with highbeam....you should go electric, and get a 60-80 gallon, well insulated tank (usual 'rule' is 20 gallons per bdrm).  Your boiler is aok being shut down for the summer.  The standby losses on a modern electric tank are very low.

If you want more numerical proof, you have to estimate your standby losses in the summer. 

I put a run timer on my boiler to track my usage accurately. My boiler has no calls for heat cuz I switched my heating to a HP....

My wife and I and two young kids use ~100 gallons of oil in a tankless coil, per year to actually heat water that was delivered.  But my boiler still burns ~300-350 gallons a year. AND I up-insulated the case AND eliminated a thermosiphon in the hydronic loop.  So, minimum I am burning 2+ gallons of oil on standby for every 1 I burn to heat water.  If your standby losses are similar, you are spending >$1000/yr on DHW.

To estimate YOUR oil standby, take your summer usage, and subtract off maybe 0.2-0.3 gal/day for actual DHW delivered.


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## wannabegreener (Jan 7, 2012)

woodgeek said:
			
		

> I agree with highbeam....you should go electric, and get a 60-80 gallon, well insulated tank (usual 'rule' is 20 gallons per bdrm).  Your boiler is aok being shut down for the summer.  The standby losses on a modern electric tank are very low.
> 
> If you want more numerical proof, you have to estimate your standby losses in the summer.
> 
> ...



This is pretty interesting.  A couple of points I'll comment on with more questions.

PSNH - power company for NH reports $77 per month for dhw from an electric tank.  Maybe they are overpricing it, but if anything, I would think that they would underestimate it.  At $77 per month, I'm talking $924 per year which would be the same as burning .87 gal per day at $2.91 per gal.  A little low for oil, but my prebuy price is 2.99 this year.

Can you explain how you came up with the 100 gal for dhw, but 350 total.  I get the total, but don't understand the other.  I have been tracking my usage for 10+ years with my old and new boiler.  The least average usage I saw in the summer was .87 gal per day.  When I looked at the system 2000 website they indicated the oil usage in the summer should use .2 gal per day for dhw so the .2 you have above sounds interesting.  My heat is definitely turned off in the summer.  The only thing I couldn't tell from the system 2000 web site is if the .2 was for their solar/oil unit or just the oil unit.  

Can you show me the timer you have on your boiler.  I could use that in the summer when the heat is off so I could get an accurate reading for dhw oil usage.  

I'm leaning towards solar since it will be almost free once it is installed.  Just cost a little for the electricity to make the pumps run.

Thanks again


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## btuser (Jan 7, 2012)

If you're still using your boiler for heat in the Winter then an indirect is going to be your most efficient option when you factor Summer/Winter into the equation.  If its just for hot water and the boiler is for emergency/backup heat I'd definately go with an electric.  I looked into the heat pumps but decided I don't have the opportune setup (small room) and because I'm so far North with a heated basement I'd only be gaining efficiency 4-5 months/year.  

I'd avoid the oil-fired hot water heater.  Another burner to service + the open flue wicks heat out of the tank just like your boiler does.   Keep the btus in a tank that doesn't have a natural chimney and the water will stay hot for days.  I've got a mixing valve on my tank so a 40g behaves more like a 50 gallon. I'm looking for a cheap/free indirect so I can preheat my hot water with both a homemade solar option and also do a post-purge on the boiler.


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## btuser (Jan 7, 2012)

greenteam said:
			
		

> you can equip your boiler with an automatic damper that opens upon ignition and closes upon completion of exhaust cycle, therefore retaining heat in the fire box a lot longer



They work but most boilers have a much smaller r-value than a tank's typical r19+, plus larger piping will migrate heat away faster than smaller regardless of heat traps etc. I'm talking pennies difference per cycle and everyone has to cost it out for themselves. My goal is gallons of heating oil, and quite honestly dollars/shower often takes a back seat to gallons per year. I'm not crazy with it but a 10yr payback period for me is not out of the question. In the back of my mind I'm always thinking: "Hmmm. Straigth of Hormuz+terrorist attack= $10/gallon heating oil! That changes figures in a hurry. 


I like the idea of automatic dampers but personally have had a lot of problems with my own as well as others I've seen installed. They're kinda cheap and take a beating being so close to the hot flue gases. Plus a boiler/tank that only fires 2-5 minutes to retain temperature is going to soot up a lot quicker than one that has to charge an indirect. Either one is pretty wasteful compared to solar, on-demand or good ol' fashioned conservation. I saved more by putting an egg timer in the bathroom for my daughter than I did by installing a 5k high eff heating system. I suppose if I get rid of the egg my payback period would improve, but that doesn't make much sense either. I'm not crazy.

No, I'm not. I'm not crazy.

Not crazy


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## woodgeek (Jan 7, 2012)

greenteam said:
			
		

> I augmented my tankless  oil burner with a solar hot water system fed threw its coil  if the water is warm enough it does not need to cycle
> if a cloudy rainy week I have it on demand



Um.  If 2/3rds of your usage is standby, how much does preheating the water using a solar system really help?  Do you shut down the boiler unless the solar tank is hot?


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## Seasoned Oak (Jan 7, 2012)

btuser said:
			
		

> greenteam said:
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I have a different approach to teenager hour long showers. I have a small electric water heater (30 Gal) set on 120. You can get a nice 15 minute shower but then the water starts getting cold. Nothing limits teen showers like cold water. My dish washer and clothes washer have their own builtin water heaters so they are not affected. The result ,my electric bill barely budges in spring when i convert from HW from my coal boiler to electric for the summer.


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## woodgeek (Jan 7, 2012)

wannabegreener said:
			
		

> woodgeek said:
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The one I got is like this one--I googled around awhile and found one for $20-30.  
http://enmco.thomasnet.com/item/enm...meters/t18-ac-powered-hour-meter/t18bh52bc09?
Wired it across the pump/blower motor, it counts when it sees 120V.  Multiply by 1.1 gph nozzle to get oil burned, figure out when to buy more.

If you figure out how many minutes a day you run your shower, and gpm on the shower head, you can ballpark that 80-100 gallons of fuel oil (at 80% eff) should provide the BTUs required for a year of DHW.  I confirmed this with my timer, by getting my background reading when I went out of town for a weekend, etc.

On solar, read the fine print.  You still have to pay backup, usually electric.  In most cases, the backup will be at least 30%, up to 50% if the system is not properly sized/installed, or your local resource struggles in the winter (as it would in NE).  So, solar DHW is not 'free', it costs 30-50% as much as electric DHW.  I decided that at that price, the HP water heaters looked a lot more appealing, and had shorter payback (relative to oil or conventional electric).


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## woodsmaster (Jan 7, 2012)

I have a famly of 5 (3 girls lots of baths ) We used to use elec. WH to the tune of $75.00 / month. I now use
a wood boiler and the money save on hot water would buy 2/3 of my total wood heating home shop and dhw.
It was a large investment, so It will be a few years before I see a return.


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## WES999 (Jan 8, 2012)

I was in the same boat you are in. I was using about 1gl/day in summer for DHW. About $100 mo.
I found a nice 80gl electric water heater on CL for $50. 

I have an hour meter on the water heater. Over the last year it ran for 180 hr. If I did the numbers right that comes out to $11/mo.

Now I do have a solar pre-heater so you need to account for that. But when I estimated the cost for electric hot water by itself I came up with $25-$30/mo. (A lot less than $100/mo for oil)

The $77 dollar figure seems high.

I think electric can be cheaper than oil.

BTW the oil man is FIRED. :lol:


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## otsegony (Jan 10, 2012)

This is an interesting discussion for me as I made the move to a GE Geospring heat pump hot water heater.  I did this because I was trying to accomplish as much space heating with my basement located wood stove and I found that with a family of four that includes two teenagers providing our DHW through the oil-fired boiler wasn't giving us much savings.  Previous to this I had tried various things, including turning the hot water thermostat all the way down or running it at a minimal temperature.  All of them saved oil consumption but were vetoed by the family. 
Some facts: total annual oil consumption to  heat my 2000' sq.ft. well insulated house in a cold climate and provide hot water was about 700 -750 gallons without the woodstove.  I calculated that the DHW took about 250- 300 gallons of that.  When I started heating with wood, my oil consumption dropped by at least 50%, but it was hard to get further savings because once the boiler is running for the hot water, why not turn the thermostat up in one of the upstairs rooms and get that comfortable?  It was a bit sloppy, but when you are outnumbered by the family it is hard to say no.
This October I installed the GE Geospring ($1,000 on sale at Lowes) and turned off the power to the boiler.  So far electric consumption in Nov and Dec are within 2kw hours of last years (I think the heat pump and the oil boiler with zone pumps have a similar current draw) and our oil consumption in this very mild winter is down to 0.  I think that might change if it ever gets below 15 degrees for a sustained period and I have to heat the upstairs bedrooms a bit, but I am still very happy with it.  Also, my wood consumption has gone up (not surprisingly) a good amount.  I won't know how much until the end of the season when I can calculate total use, but I'm thinking it is going to be in the range of 30 - 40%.


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## begreen (Jan 10, 2012)

I am looking at the GeoSpring system. For those who what installed one, do you notice the heat loss in the basement? If so, by how much? How difficult was the install? Did you put in a new storage tank or did you use your old electric(?) tank?


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## woodgeek (Jan 10, 2012)

BeGreen said:
			
		

> I am looking at the GeoSpring system. For those who what installed one, do you notice the heat loss in the basement? If so, by how much? How difficult was the install? Did you put in a new storage tank or did you use your old electric(?) tank?



The Geospring is an integrated unit, HP + tank.  You might be thinking of the 'AirTap' retrofit system... The all in ones have a significantly better COP than the retrofit approach.


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## otsegony (Jan 10, 2012)

As Woodgeek noted, the Geospring is an integrated unit so it has its own tank.  Both Sears and Lowes sells them and you can see them on-one the pages also have comments and downloads like the owners and installation manuals you can look at for your information.  As to installing the unit my plumber/electrician hooked it up and said that it was essentially the same as connecting a conventional electric hot water heater, the power needs are the same (a 220v circuit) and the plumbing hook-up was identical.  Anyone with any experience with regular hot water heaters would have no difficulty hooking up the Geospring. The unit does seem to cool the basement a little bit, maybe 4 or 5 degrees, but that may also be because I am no longer running the oil-fired boiler with the radiant heat tubes that run through the space. When it is running it puts out a flow of cool air from the heat pump unit.  The only thing that I can think of to compare it to would be the air conditioning vents in the center of the dashboard of the car run at a low to moderate setting.
A couple of other things to keep in mind is the unit is not silent. When the heat pump is running it makes a sound kind of like a dehumidifier running at a high speed, only higher pitched.  There are a couple of videos of the unit in operation on Youtube that you might want to check out. Also, if your basement is damp you will need to deal with the condensation that comes off of it.  There is a tube that can be directed towards a floor drain or condensate pump.  I haven't had any to deal with so far, but my plan in the summer is to just have it run into a bucket and then periodically empty that.


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## maple1 (Jan 10, 2012)

Have you guys checked out a Geyser?


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## wannabegreener (Jan 11, 2012)

woodsmaster said:
			
		

> I have a famly of 5 (3 girls lots of baths ) We used to use elec. WH to the tune of $75.00 / month. I now use
> a wood boiler and the money save on hot water would buy 2/3 of my total wood heating home shop and dhw.
> It was a large investment, so It will be a few years before I see a return.



Woodmaster,  what are you using in the summer.  I can't imagine you are using your wood boiler in the summer.


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## maple1 (Jan 11, 2012)

A wood boiler with well insulated storage is great for DHW in the summer. Fire it once a week and forget about electric or oil heat.

So nobody's checked out the Geyser?


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## mrfjsf (Jan 11, 2012)

As others have said...Go electric. Expensive in comparison to NG or wood but still cheaper than .9 g/day of oil just to heat water. My oil cost is $3.95/gal. My electric bill is $4.25 average cost per day. That is with a 40 gal electric HWH set at approx 140 degs, electric stove, 7 lamp posts going down my driveway, and a wife that doesnt know the meaning of shutting off the lights when you're not in the room. 

You do the math...


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## wannabegreener (Jan 12, 2012)

My electric company reports that a 20 gal tank will cost $77 per month to run.  Electricity is expensive in NH.  I would expect that I would need a larger tank to run than that.  Someone saud that a larger tank would cost the same to run, tbut not necessarily.  If a 20 gal yap tank is large enoug for a 2 person household (just guessing here) then that means two showers, laundry for two, etc.  Tpif the household has 4, then you would almost double youndhw needs.  So, I would guess a cost of more than $77.  

I have contacted a company that installs solar to see what they will quote me.  I also want to contact a company that installs heat pumps.  I currently run a dehumidifier all summer to keep the basement drier, so if the heat pump will do that at the same time as heating water, I might be able to shut the dehumidifier off use the same or maybe a little more electricity for the heat pump.

I contacted the boiler company 'energy kinetics' and they claim that my boiler should be able to heat dhw with .2 gal of oil per day.  This seems a little impossible unless you use almost no water, and the cold water temp is a lot warmer than mine. They claim that their water tank, which I don't have, is a lot more efficient than my superstor.  they have some sort of stratifying tank that can suck all of the heat out of the boiler when the dhw stops asking for heat.

Here are the numbers they also claim.

They can heat 195 gal in 1 hr with a heat differential of 77 degrees.

My calculations for this are

195 gal * 77 deg * 8.34 btu/ deg gal = 125,225 btus
Their largest nozzle on the boiler they claim this on is 1 gal/hr and they claim an 86.2 % efficiency.

1 gal * 140,000 *.862 = 120,680 btus.

With no heat loss in the pipes between the boiler and tank and assuming HW tank could remove all heat from the boiler, they are already almost 4% too low on the btus.

I'm new at this so if any experts can see an error In my math or equation, I would appreciate it.

Thanks


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## wannabegreener (Jan 12, 2012)

maple1 said:
			
		

> Have you guys checked out a Geyser?



If anyone has first hand knowledge on this unit, I would appreciate your feedback/review of this product.

Thanks


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## maple1 (Jan 12, 2012)

There are bits & pieces on it in other older threads here - try some searching. I am also on the lookout for more feedback.


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## hemlock (Jan 12, 2012)

maple1 said:
			
		

> There are bits & pieces on it in other older threads here - try some searching. I am also on the lookout for more feedback.



I enquired about one in the spring.  There is some guy in New Brunswick that sells them.  I can't recall the price, but I remember thinking it seemed a bit expensive compared to prices I had seen in the US (typical for Canada I guess).


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## hemlock (Jan 12, 2012)

I had indirect oil for DHW, and it cost a fortune.  Removed the "Triangle Tube" tank and coil, and installed an electric Marathon DHW heater, and have notice substantial savings.  I would estimate about $60 per month savings over oil at roughly $4.50 per gallon.


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## maple1 (Jan 12, 2012)

hemlock said:
			
		

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I did a bunch of net searching this fall - must have found the same fellow that you did. Around Miramichi I think, and around $1200. My current DHW is a coil in an oil boiler that I need to keep hot all year round - so I'm needing to make a change. Still not sure what to though - still leaning to a cold start oil boiler for DHW & heat backup with indirect hot water tank, along with a new wood unit. Decisions decisions...


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## velvetfoot (Jan 12, 2012)

Can a heat pump be used for heating water for building heat?  I haven't seen one.  It'd be a way to move heat around when one doesn't have air ducts.  If you had a stove in the basement, you could also extract heat with the heat pump and move it to the second floor.  
Oil is just too expensive.


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## Highbeam (Jan 12, 2012)

wannabegreener said:
			
		

> My electric company reports that a 20 gal tank will cost $77 per month to run.  Electricity is expensive in NH.



Here's your problem, you're hung up on this. 

A 20 gallon tank costs nothing to run if you don't use it. It can certainly cost more than 77$ if you overuse it. The cost to heat X gallons of water is the same nomatter how big the tank is. A btu is a btu, a watt is a watt.

When you say heat pump are you considering a heat pump water heater? Those are actually pretty attractive for basement installs where you also need humidity control.


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## velvetfoot (Jan 12, 2012)

Me?  I was talking air to water heat pump for building heat as well as dhw.


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## woodgeek (Jan 12, 2012)

velvetfoot said:
			
		

> Me?  I was talking air to water heat pump for building heat as well as dhw.



I poo-poo'ed this in another thread....and subsequently heard that Daikin makes the unit you want.  Sorry about the OT, but the Daikin 
product has an outdoor coil with defrost controls, etc, and dumps the heat into a hydronic loop.  I think the loop should be 'low temp',
i.e. radiant floor or oversized radiation, etc.  I could see it only if you had a not-super cold climate, no need for A/C, low temp hydronic
radiation AND no ductwork!

The OP def needs to get a HP water heater....his boiler will tolerate summer long shutdown, which is the only contraindication otherwise.
An indirect system still has parasitic losses, is expensive, and even if the boiler goes cold between firing the tank, I can't believe all the
heat gets scavenged out of it at the end of every cycle.


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## wannabegreener (Jan 13, 2012)

Highbeam said:
			
		

> wannabegreener said:
> 
> 
> 
> ...



Highbeam

I know I'm hung up on this.  Mostly because nh has high electric costs.  People I known that have electric HW tanks, want to change them because of costs.  I understand that if you don't use water, it will be fairly cheap, but I'm assuming I'm using water.

If I'm using .87 gal of oil a day with an 86% efficient boiler, I'm putting 105,000 btus into heating water.  Granted that some of these btus are left over in the boiler and lines leading to the HW tank,  I just don't know ho to figure this amount out.

.87 * 30 days * $3.50 = 91.35 per month for oil

1 watt-hr is 3.41 btus

105,000 / 3.41 = 31kwh

31 khw * $.17/kwh * 30 days = $158.00

My left over heat would have to be 43% of the total used.  I can't imagine it is that high.  I have a low mass boiler that tries to dump all extra heat into the last zone asking for heat.

If my numbers are wrong, please let me know.  

Thanks


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## wannabegreener (Jan 13, 2012)

Highbeam

Yes, I was thinking heat pump for dhw.  I currently run a dehumidifier during the summer, so I was thinking/hoping the heat pump would kill 2 birds with 1 stone.  Heat my dhw and dehumidify my basement at the same time  The heat pump would increase my electric usage/costs, but I wouldn't be running the dehumidifier so maybe somewhere near a wash???


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## woodgeek (Jan 13, 2012)

wannabegreener said:
			
		

> Highbeam said:
> 
> 
> 
> ...



Your calc assumes that your elec tank would have the same standby losses as your oil system.  You are correctly comparing the cost of oil and elec BTUs, but as we said before we think you are losing 2 BTUs to standby losses for every one that goes to delivering DHW.  So, if a conventional elec tank used 1/3 the BTUs, its $53/mo and a HP unit at a conservative seasonal average COP=2 would use half THAT, or $26/mo.

IOW, the $77/mo for a tiny tank number from your utility is utter BS.


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## woodgeek (Jan 13, 2012)

If you want to go crazy, measure the gallons per minute in your shower, estimate the minutes per day, and assume a Delta temp of 60Â°F (45 supply to 105 shower).  Take the product * 8 lbs/gallon and that is your BTU/day for showering.  IF you are doing all your laundry in HOT, stop, and worst case by different detergent.  Add 20% safety factor to the total for dish/hand washing.  

Most households use ~10-20,000 BTU/day/adult.  See where you come in.  Your calc is correct, if you come in under ~60,000, implying less than 60% delivery eff, you come out ahead with **conventional electric**.  For a HP system, it will run conventional in the winter (making the previous calculation useful re 'switching' back to a boiler indirect in the winter).  In the summer it will have a COP of 3-4 and thus cost equivalent to $1.25-$1.50 oil on a BTU to BTU basis AND give you free dehumidification.  That is so cheap that even if (gasp) the price of oil collapsed, i.e. $2, you are still saving money, and if the cost of oil goes above $4 you can save plenty of money in the winter too.


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## EJL923 (Jan 13, 2012)

$77/month for hot water seems awfully high.  We have a 50 gal hot water heater.  I don't know what the hot water heater pulls, but our monthly bill fluctuates from $100-$120/month depending on the time of year.  Our electric with everything added on is about 0.18/kwh.  I also like the fact that it is virtually maintenance free.  My oil fired furnace only gets used for the occasional supplemental heat.


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## maple1 (Jan 13, 2012)

A Geyser can be hooked up very easily to almost anything. I have coils in my oil burner, I think I could hook it up to my coils and it would keep my oil burner warm all summer quite cheaply. Maybe even add on a cheap electric hot water tank for more storage & back up if I wanted - they seem to have lots of possibilities.


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## Highbeam (Jan 13, 2012)

wannabegreener said:
			
		

> If I'm using .87 gal of oil a day with an 86% efficient boiler, I'm putting 105,000 btus into heating water.
> 
> If my numbers are wrong, please let me know.
> 
> Thanks



That's the only disconnect I can see. You are not putting 105,000 btus into the water, you are putting 105,000 btus into a machine to heat water and only getting a portion of those btus back as hot water. Your 86% efficient boiler is only 86% efficient when it is at steady state being used hard for a long period.

With an electric resistance heater you get nearly 100% of the btus actually delivered to the water.

17 cents per KwH is not expensive. You have relatively cheap power. 

I really hope you go for the HP water heater since it is better than 100% efficient. Much better than 100% and then you get reduce the load on the dehumidifier for even more savings.


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## Jack33 (Jan 14, 2012)

I was in a similar situation as the OP.  I calculated I was using .75 gallons a day just to heat DHW with my oil fired boiler.  I have a 40 gallon DHW storage tank off the coil controlled as a zone by the boiler.  

I choose to install a new 40 gallon electric hot water heater.

I am in NH and have PSNH as my electric provider.  Before the electric water heater, my bill was about $100 a month year round (excluding July/Aug do to AC useage).  After I installed the water heater my bill is still about a $100 a month.  2 adults in the house and we don't conserve hot water other than washing clothes in cold water only.  I don't sacrifice hot showers, dishwasher, etc.  I have the temp on the water heater set at 120.  I figure the boiler uses a fair amount of electric running the gun, stats, controller, 2 circulator pumps, etc.

I installed the electric water heater after my boiler storage tank.  So regardless of the season, inlet water flows through the coil, into storage tank, and into the electric water heater.  So during the winter, I basically have 80 gallongs of DHW in storage.  All I have to do is kill power to the boiler and to the storage tank which has a t-stat on it.

I installed this Dec. 21 of 2010.  I have about $600 into the electric heater, copper pipe, 50Ft of wire, ball valves, exp tank, etc.  I figure from April-Nov oil useage was about 200 gallons of oil prior to install.  200 gallons @ $3.50 is $700.  The pay back period was less than year. 

The estimate of $77/per month heating water with electric is way off.  I would guess I spend about $1 a day to heat water, but I am saving $1 a day in electricity by turning off the boiler.


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## wannabegreener (Jan 18, 2012)

Had a solar installer come in today to give the house a look over.  I wanted to see what they would come up with for a price.  While he was here, we talked about solar dhw, full electrical solar, and a heat pump.  They sell stiebel eltron heat pumps for hot water.  Looks like you can get them with 2 coils in case you wanted to do solar.  I'm waiting on prices for everything.  They are all very interesting and I hope to be able to shut down my boiler in the summer.

One thing I don't quite understand is the 'First hour rating".  On the heat pump, the first hour rating is 76 gals, but it is an 80 gal tank.  So, if you have 80 gal of hot water and you start using it, if the rating is only 76, does this mean that as the cold water enters the tank, obviously it mixes with the hot, but that the heat pump can't even recover enough to use the complete 80 gals? Is that normal for a heat pump?, what about other fuel sources like pure electric, oil, or gas?  I thought I finally understood what this first hour rating was all about.

My roof ridge goes N/S so not optimal for anything solar.  They can do it by lifting/tilting the panels for hot water.


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## woodgeek (Jan 18, 2012)

wannabegreener said:
			
		

> Had a solar installer come in today to give the house a look over.  I wanted to see what they would come up with for a price.  While he was here, we talked about solar dhw, full electrical solar, and a heat pump.  They sell stiebel eltron heat pumps for hot water.  Looks like you can get them with 2 coils in case you wanted to do solar.  I'm waiting on prices for everything.  They are all very interesting and I hope to be able to shut down my boiler in the summer.
> 
> One thing I don't quite understand is the 'First hour rating".  On the heat pump, the first hour rating is 76 gals, but it is an 80 gal tank.  So, if you have 80 gal of hot water and you start using it, if the rating is only 76, does this mean that as the cold water enters the tank, obviously it mixes with the hot, but that the heat pump can't even recover enough to use the complete 80 gals? Is that normal for a heat pump?, what about other fuel sources like pure electric, oil, or gas?  I thought I finally understood what this first hour rating was all about.
> 
> My roof ridge goes N/S so not optimal for anything solar.  They can do it by lifting/tilting the panels for hot water.



Ok, the water in a tank stratifies, hot on the top, cold on the bottom, which is why the heat is delivered to the bottom.  As the cold comes in the bottom, the hot leaves out the top.  Without any added heat, the FHR will be less than the volume because of 'dead volume'...hot water that can't leave, or imperfect stratification--it will be close anyway.  Compared to all fossil heaters, all elec heaters will have slower recovery.  110 kBTU/h = 30 kW.  With an electric heater, that would be 135 amps at 220 V!  Thus, while a fossil heater could regenerate the water in 30 minutes, a 5 kW element (typ) will take 6x longer, or 3 hours.   Since the heat pumps are typically sized around 0.5-1 ton (6-12000 BTU/h), they will take 10-12x longer, or 5 hours to recover.  Most HP systems have a nice controller that allows you to use both heaters ('hybrid' mode) to get faster recovery, e.g. when you've got a houseful of guests, at a slight loss of energy savings.  

I also looked into solar, and was surprised when the equivalent to FHR worked out to be just 50% of the tank volume.  IOW, the backup usually comes on when the tank is half hot and half cold, so the tank can only absorb solar heat into its bottom half.  Equivalently, you need a tank which is ~2x your daily usage to avoid blowing a lot on backup.

As I have said elsewhere, the quote for commercial solar DHW was higher than a HP system even with a 70% rebate, and if I used the (conventional elec) backup for 40% of my seasonal needs (likely looking at my low winter solar resource), then the (electrical) operating costs were nearly the same!

Of course, the lowest operating costs would be for a solar DHW + HP backup, but by then I would have >$15k of hardware tied up to get save a few hundred $$ a year.
Even worse, the HP wouldn't work in my application in the winter (semi-conditioned install), so there would be not advantage to having both.


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## frizman86 (Jan 25, 2012)

I have read all the way through this thread and boy am I confused. I currently am running my hot water heater on Propane at $2.50 a gallon. it is costing me around $50 a month. I switched from a propane fernace to a pellet stove. The furnace + hot water heater cost me $500 a month for LP. The pellet stove I am factoring in $100 a month for 4 months a year for two years to cover the install cost, and $125 a month in pellets. So my Propane bill is around $50, and pellet heat bill around $225 a month. So I am saving $225 a month. $50+$225=$275. Electric here cost me $.15 per kw, and acording to the Whirlpool website there most effeciet 50 gallon ( I figured that was average) uses 4622 kw a year. So .15 x 4622= 693.3 for the year then / by 12 and it is $57.78 a month. Now that is for me. it looks like the average here is .10 per kw so even then it would be $38.51 a month. So for me propane is cheaper, then electric. This is all asuming they are not lowering the numbers a little to make people want to by their product. Were I am confused is how is it only making your bill around from $5 to $16 more a month. You guys must have some very cheap energy. These things use 4500 watts per hour. thats 4.5kw or at even .10 cents per kw thats .45 cents per hour they are running. now I know they dont run all the time but even then if it is running say 8 hours total in a day. .45x8= $3.6 a day X just say 28 days a month is $100 a month. 

I have a wierd feeling if you were to put a energy monitor on your house and and monitor it for just a day with no change, Then shut the breaker off for the hot water heater for a day, you will then see a big differance. My weifes parents own a electric hot water heater that is 5 years old. Thier bill was $112. somthing for the month of Dec. and they are running a wood burning stove instead of a fernace. 

Our bill for the month of Dec. Was $55. something. And that is running, normal light usage/TV (10w CFL's and 32 inch LCD TV), a fridge (high efficentcy got summer 2011), a stand alone freezer (15 years old), pellet stove , 55gal salt water aquarium, range, dishwasher, well pump, and dryer. It is a 2,000 sq ft home with two adults, and .15 cents per kw. I guess I just am not seeing were it is so cheap to run. Even if it were to only cost $38 a month it still would not justify buying a $1500 electric hot water heater, with a $12 a month savings it would take me 10 years to recoupe the money back.


For me personaly I am trying to find a way to use the pellet stove or pellet stove vent pipe to keep the hot water heater hot in the winter and do away with propane altogether for 3-4 months.


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## woodgeek (Jan 25, 2012)

Your numbers make perfect sense for you--your propane and elec are similar in cost on a BTU basis.  The difference is in using a hydronic boiler to heat your DHW using a tankless coil.  The standard oil-fired boilers out east have a really large standby loss, 0.5-1.0 gallons oil/day.  At $4/gal that is $2-4 a day for standby loss, before you even think about the BTUs needed to heat the water.  In my case, I am burning ~300 gallons oil/year, just for DHW, works out to ~$100/mo.  Your point is well taken...I could get a propane water heater and have a good operating cost.


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## frizman86 (Jan 25, 2012)

I Hope I did not come across as trying to push propane more the electric. I am just trying to wrap my head around how it is only making other peoples bills go up a few dollars.


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## nate379 (Jan 25, 2012)

The standby loss on any modern water heater with a tank isn't much.  Something around 1/2* per hour.  Tank vs tankless, there isn't that much benefit IMO.

I have shut mine down before to do work on the boiler and even after a couple days there is still fairly hot water, provided I am conserving the water.  

I'm not one to stand in the shower for long either though, pretty much a 15-20 min chit/shower/shave guy... as I'd imagine most of us are.


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## woodgeek (Jan 25, 2012)

frizman86 said:
			
		

> I Hope I did not come across as trying to push propane more the electric. I am just trying to wrap my head around how it is only making other peoples bills go up a few dollars.



No problem.  You just have to wrap your head around ~5 million oil-fired systems in the US that were designed for and made perfect economic sense when oil was $1 gallon, and which now make so little sense at $4 that almost anything you replace it with (e.g. rabbits on treadmills eating organic micro-green arugala) will have a nice ROI.  

Something I have thought about....we spend a lot of time here talking about (simple) ROI or 'payback'.  Just b/c something has a quick payback doesn't mean its the best solution when changing/upgrading a system.  One really should think about cost of ownership, like install cost + operating cost over a time span of your choosing (i.e. 10 years).  In the case of this thread, the OP and any oil burner can make a long list of alternatives that have great payback, but the fastest payback does not equal the lowest cost of ownership.  

It is my contention that an electric HP system will have to lowest cost of ownership over ~10 years, with the exception of a NG-fired system that many of us do not have access to.  Specifically, while more upfront than a conventional elec tank, the lower operating cost makes it come out ahead.  While a solar DHW system has even lower operating costs, it isn't all that much less if the electric backup provides 30% of the BTUs, so it is hard to recoup the initial outlay unless you build it DIY.

I am not an electric chauvinist.  I just don't have propane now or a great place to put a tank. The propane people currently share the oil folks' pain on a cost per BTU basis, but for a well insulated tank-type propane fired DHW system (oil equivalents are available but seem rare to me), the lower standby means that they are not useless.  And since propane is a byproduct of gas fracking, it is possible that expanded fracking operations will eventually drive down the cost of propane, as it already has for NG.  Or it may not.


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## Highbeam (Jan 25, 2012)

And where in the world must you pay 1500$ for a 50 gallon electric water heater?


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## nate379 (Jan 26, 2012)

I'd be interested to know what the cost per month is on a std nat gas water heater vs a boiler mate/indirect fired water heater?

During heating season it's probably not much extra to heat DHW off the boiler since it's likely already running, but in the summer I have to wonder what kind of heat loss from the pump/piping and actual boiler.  My setup is a cold start boiler too so it has to heat 60-70 water in it to 120* just to get to the point of warming the water too.

I do know summer use for natural gas runs me around $30-40.  2 people and kitchen stove and dryer also are gas.


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## woodgeek (Jan 26, 2012)

Highbeam said:
			
		

> And where in the world must you pay 1500$ for a 50 gallon electric water heater?



http://products.geappliances.com/ApplProducts/Dispatcher?REQUEST=SpecPage&Sku=GEH50DNSRSA


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## Highbeam (Jan 26, 2012)

Don't be silly. 

http://www.homedepot.com/Plumbing-W...splay?langId=-1&storeId=10051&catalogId=10053


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## woodgeek (Jan 26, 2012)

In 12 years, I will have to buy two of those, and spend $8000 on electric, versus 1 geospring and $3000 in electric.  Don't I come out $4000 ahead over that period?

Maybe your kWh out in WA are basically free, mine aren't.


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## Highbeam (Jan 26, 2012)

The point is that you need not spend 1500$ on a tank heater unless you want to. Even the 250$ water heater will be much cheaper than the oil indirect which is the topic of this thread. 

I am becoming a fan of the HP water heater if you have 1500$ to spend and can live with the noise.


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## woodgeek (Jan 26, 2012)

Highbeam said:
			
		

> The point is that you need not spend 1500$ on a tank heater unless you want to. Even the 250$ water heater will be much cheaper than the oil indirect which is the topic of this thread.



Aaah.  Agreed.


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## greythorn3 (Jan 28, 2012)

as much as i hate our on demand hw heater it cut our gas usage by 1/3 over the tank one we had before.


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## wannabegreener (Jan 30, 2012)

I'm going to guess that the on demand won't work for me because of well water.  I had it in my old boiler when I bought the house and the previous owner said that the "coil" or whatever it is needed to be replaced frequently.  This was because of the build up of minerals on the inside of the coil.  Because of this, I'm going to assume that the geyser won't work either.

I got my quote for solar and it claims that I will only save 120 gals of oil per year.  OUCH  At about 3.50 per gal, it would take about 14 years to pay this back.  That doesn't include the electricity to run the pumps so it will probably be closer to 15 years.

Anybody use the steible-eltron heat pump for hot water?  The same company that quoted me for solar sells that brand as well and gave me a rough quote of $4000-$5000 to install.  I can find the same unit on amazon for about $2000.  I can't believe it would cost $2000-$3000 for installation costs plus pipe, elbows, etc.

Still trying to figure this out.  I really appreciate all of the comments and experience in this thread and forum.


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## woodgeek (Jan 30, 2012)

I was looking at the80 gallon AO Smith:
http://www.hotwater.com/water-heaters/residential/hybrid/voltex/
which seems to be re-labeled and resold by a number of other vendors. I have plenty of space, and wanted a higher FHR than the 50 gal GE unit.

I would think that a local plumbing contractor would be cheaper than a top $$ solar company.


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## woodsmaster (Jan 30, 2012)

wannabegreener said:
			
		

> woodsmaster said:
> 
> 
> 
> ...



 Sorry for the slow response. Been a while since i've looked at this thread. I will heat my hot water with the wood boiler
this summer. I have to fire once every 5 days for hot water. My wood is free other than time and a little gas and oil for
the saw. I hope to build some solar panels for summer water somtime in the next couple of years and tie into the
boiler storage.


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## begreen (Jan 30, 2012)

woodgeek said:
			
		

> BeGreen said:
> 
> 
> 
> ...



So I have now looked at the GE unit too. (Thanks for the HD link Highbeam!) One question I have is about the recovery time is for a full tank? Is it slower than resistance electric or about the same? Or does it just go to resistance heating for rapid recovery? How noisy is it? The spec says 58db which seems a bit high. That maybe ok for a garage but I am not sure I like that for a basement or closet installation.

PS: Nevermind, I just found this review on GE's site for the GeoSpring. The more I look, the more bad reviews I am finding for these hybrid heaters.

http://blog.yagelski.com/2009/11/ge-hybrid-water-heater-does-heat-pump.html


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## Highbeam (Jan 30, 2012)

I have no basement or garage so the water heater would be in a hallway or other heated living space. The sound levels appear unacceptable. Too bad they couldn't do a mini-split style outside unit.


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## begreen (Jan 30, 2012)

I also went to Lowes website for reviews. There are a lot of compressor failures being reported. I've decided to stick with resistance electric for now.


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## woodgeek (Jan 30, 2012)

interesting.....

My location is a large attached garage which already has a dehumidifer, so I wasn't worried about noise and figured I could save.  I figure it will run conv in the winter, and think my ROI will still be decent.
I had also decided that the GE unit FHR was too small for a family--that's why I want the 80 gal Voltex.

I guess I'll get the extended warranty!

As for the questions....the recovery on HP is supposed to be ~5 hours, not much longer than for a conv elec tank.  It seems that when the compressor fails, it reverts to the elec coil---you are not w/o DHW until the repair.  I wish my oil boiler could do that.

When I quote out/pull the trigger....I will post.


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## velvetfoot (Jan 31, 2012)

I'm thinking of adding a pellet boiler and maybe also use that for hot water.


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## EJL923 (Jan 31, 2012)

Well im a little confused with all the acronyms, but the efficiency goes down on the heat pump when the ambient temp is below 50Â°F, and not even recommended below 45.  This would rule out garages and some basements.


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## woodgeek (Jan 31, 2012)

My unconditioned garage runs >50Â°F about 9 mos of the year.  As I understand it, the controller will automatically switch from the compressor to the coil and back again as needed when the ambient temp drops too low.  My estimates suggest that running 'conventional' for 3 mos of the year will cut my payback, but not much.  The operating cost should still be half that of a conventional elec tank, and about a quarter of my current tankless coil/oil boiler combo.

Assuming I can find someone to install a 400 lb unit!


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## GaryGary (Jan 31, 2012)

Hi,
OK -- after 6 pages with no mention of solar, I thought someone should bring it up 

Solar might work particularly well in your case, since a solar water heater could provide essentially 100% of your hot water during the part of the year you would not be running your oil burner except to make hot water.  I've heard from several people who have wood winter space and water heating and use solar water heating in the summer and it works well for them.

This is my current system: http://www.builditsolar.com/Projects/SpaceHeating/DHWplusSpace/Main.htm
It provides both domestic water heating and limited space heating.  
It can be scaled back to do only solar water heating.  

Very simple -- the only moving part is the collector circulation pump, which is a regular, lasts forever, HVAC circulator (Grundfos 15-58).

Very cheap -- the water heating only DIY version can be built for $1000 with just about everything coming from Home Depot.  We got a $500 MT rebate, so total out of pocket was $500 -- a less than 2 season payback.

Gary


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## mr.fixit (Feb 1, 2012)

+1 Gary
My solar HW system (based on your design)is still working great after 3 years.
I also put in my own PV system last year.
I have to stop looking at your website! Next thing ya know I'll be buying an Elec-trak!
Thanks for all your free information  that you provide us.


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## woodgeek (Feb 1, 2012)

Ok, a rebranded 80 gallon AO Smith unit has three positive reviews on Lowe's site:

http://www.lowes.com/webapp/wcs/sto...cId=SEARCH&productId=3370964&cm_mmc=SCE_gps-_

Also a big kudos to Gary for all he does....but sadly I have neither the site for solar (north side of a wooded ridge) nor the time to build a DIY collector.


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## steviep (Feb 2, 2012)

During the winter I have a stripped out water heater next to my woodstove that heats the water to 110 / 120 degees. It preheats the water before going into the gas water heater. For the summer I plan on building either a system like Garys or a simple Batch heater.


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## wannabegreener (Feb 2, 2012)

I have had a solar company come in and give me a quote.  They want to put up 2 flat panels and they claim I will save only 120 gal of oil per year.  This seems crazy especially since the payback will be over 15 years.  I'm having a couple of others come out to give me a quote (money wise and oil saving wise).  I have heard from a poster in Maine that his payback will be about 6-7 years. That looks a lot better than 15 years.

I also run a dehumidifier in the basement all summer and from my guess, it is costing me $35 or more each month.  So, if I could put that electricity into a heat pump I would essentially get hot water for free.  (after the purchase of the heat pump).

Thanks for the point to your web site.  I'll take a look at it.


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## woodsmaster (Feb 3, 2012)

Check out do it yourself solar. If your handy you may be able build a couple solar panels and install them yourself for a lot less.


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## Rhone (Feb 3, 2012)

Oh my god my post was lost.  I guess I been away too long.  

I'll just make the response quick then.  I started with a tankless oil system, it kept 3 gallons hot in the coils so there was always instant hot water but supposedly also on-demand so there wasn't much loss.  It had a lot of loss, as it didn't shut the intakes ever so when it wasn't running my basement air would be sucked into the unit, pass the coils cooling them right down, and go out the flue.  It always cycled on/off.  I was using 230 gallons/oil per year even though I was shutting it off during the day and night.  

I purchased a 3 panel solar system from http://www.radiantsolar.com/solar_domestic_option.php including the tank.  I hooked the tank to electric while I poked at the solar tubing in my free time.  To my surprise, my electric bill only went up about $25/month (I pay $0.23kWh) so it was a huge savings.  But, as others have pointed out there's no standby losses.  The install was pretty easy, I am a DIY.

I got the solar hooked up (I live in VT) and I shut the electric off so I was just 100% solar for my hot water and from the 2nd week of January to the 2nd week of December I only had to turn on the electric to the tank 11 times.  Compared to oil, it was a huge savings today.  230 gallons of oil saved at $3.70 per, that's $800/year!  Compared to electric, I was only paying $300/year switching to the electric tank and saving $250 from solar so the payback is 5-10 years.  In the end, with rebates, I ended up paying $2,500 after rebates/credits and I did it myself but I did some stupid stuff like, used special $6/foot insulation and 1" type "L" pipe which is not standard so it was so expensive.  I should've just gotten regular black foam insulation (for inside) and 3/4" type "M" pipe (which is standard and cheap).  Plus mistakes like, when I dry fitted my 1" connections there's so much friction I couldn't remove them not even with a hammer or pliers and torch!  I had all my panels dry fit together in 2 arrays ready to solder then couldn't get it seperated to solder I had to cut out all my fittings and redo it all.  Just using 3/4" type "M" pipe and regular foam probably would've reduced my cost by $1000 at least.  I do love solar and glad I did it.  

I'm not a fan of evacuated tube solar nor photovoltaic, let me know if you have questions.  Thanks


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## otsegony (Feb 4, 2012)

I posted previously in this thread about the GE HP hot water heater, but I will provide a bit more information based on another month's usage.  

   - Electric usage is still within a few kwh of last year's bill.  I attribute this to the fact that I was using my oil-fired boiler last year and     between the burner and the pumps it used a fair amount of electricity. 
   - Operationally the HP water heater works very well.  The 50 gallon capacity has been more than enough for my family of four (two adults, two teenagers) with no shortage of hot water noted even after the morning shower routine. 
   - Having both the HP hot water heater and the wood stove in the basement is working well with only a moderate increase in wood consumption being noticed. However, this past couple of weeks I've been away and unable to tend the fire as I usually do and I've run into a part of our wood supply that is not as well seasoned as the rest.  The result is that I've noticed that the cool air coming off of the HP water heater has made the cellar cold and it is harder to heat up with the wood stove.  The lesson learned is to keep the wood stove burning hot and strong and double check the wood supply before bringing it in.

I hope this is useful information.


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## wannabegreener (Mar 22, 2012)

Just signed a contract for solar dhw.  Waiting for all of the rest of the paperwork including the nh rebate papers. Not sure when it will be installed, but I can't wait for the savings to begin.   From another thread, I mentioned that I had the nh energy audit done. With the work they did, they claim about 130 gal of oil savings and this should save me another 200 gal. (I hope).  If these numbers are right, I will be below 300 gal of oil and 2.5 cords of wood per year.  If I can get some of my wood heat to the second floor, I should be able to reduce the oil usage a little more and maybe not use any more wood.  The room I have the fireplace insert in is usually between 76 and 80 degrees.  I have been keeping records of oil usage based on delivery so it should be easy to see what is being saved.


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## billb3 (Mar 22, 2012)

Now you'll be cursing cloudy weather.


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## wannabegreener (Mar 23, 2012)

I figure my well water is probably around 50 so even when it is 70 and cloudy, it can preheat my water to around 70 and I gain 20 degrees just from the warm weather.


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## wannabegreener (Nov 24, 2012)

Just wanted to give an update. I got my solar installed in April 2012 and got an oil delivery on April 27th.  My next oil delivery was November 14th and only for 66.2 gallons.  Without the solar, it would have been 190 gallons for hot water only, plus a few more for heat.  I also hooked up a timer to count when the hot water zone was open.  From this, I calculated my usage for these 7 months to be about 15 gallons.  This means solar saved me 175 gallons in the 7 months of usage.  I also checked my solar collector temp on a sunny 37 degree day with a good amount of wind, it was regathering 140 degrees and the solar pump was cranking.  I can't wait to se what the complete year's oil will be.

So it looks like solar is a decent choice for southern NH.


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## woodgeek (Nov 24, 2012)

great.  system details??


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## wannabegreener (Nov 25, 2012)

System includes

2 Wagner solar panels
1 80 gal superstor single coil HW tank
1 pump to pump the antifreeze solution to the panels
1 pump to circulate between the solar tank and the boiler HW tank.

Basically, when the solar panels are warmer than the middle of the solar tank, the solar pump will run.  The speed is dependent of the the temp differential.  If the solar tank top temp is x degrees higher than the boiler HW tank, the circulator pump will move the hotter water from the solar tank to the boiler tank.  When the house calls for HW, it comes from the boiler tank.  The boiler tank gets filled from the solar tank so if the water coming into the boiler tank is hot enough, the boiler will not turn on.

I put a timer on the circulator pump for the HW circuirt for the boiler.  It counts the number of hours it runs.  From mid April to mid October, it ran for 25 hours and my nozzle is a .65 nozzle so I only burned about 16 gals of oil for those 6 months.

Hope this helps.


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