And heeeeeer's the oil prebuy price!

[Tfin]

Yeah, I'd have to get someone who knew what they were doing on the plumbing end of things. Water leaks would be the last thing anyone would want. I'd assume you'd have to drain the furnace too? Refilling and bleeding the air out I'm sure isn't rocket science....but if you've never done it before.......

Once upon a time, many moons ago, I worked as an electricians helper for four year before I decided to go back and finish my undergrad. So I'd have no problems with the wiring end of things.

Ten years ago, who would of though "yeah....electric hotwater, that's the way to go....."

 

[dccampli]

Assuming $100 per month is cost for producing hot water using electric, how many gallons would this produce? So many variables come into play, makes this not an easy decision. I have a coil in my boiler that works ok for now. My electric rate is $0.20/KWH. Have never topped off the oil tank at end of heating season so oil usage is just a guess.

 

[RedRanger]

I'm hoping to make the switch to electric from oil this summer...at the current price of oil (last fillup was $4.59/gal) I figure I'm spending an easy$1200-1400 a year for DHW. Question for the general group though, tank heater or go tankless? We're a family of three, me, the wife and a 5 year old girl. We have an energy star dishwasher and other appliances (though I think my GE fridge has never operated correctly). I'm a daily shower guy, wife and kid are every other day or so...dishes and clothes get done more or less daily or as necessary.

I think that for elec. tankless you require 200 amp service? If you can`t go tankless, look for a tank with the energy star label.

 

[mayhem]

I do have 200A service into the house so my options are still open. The question is, is tankless the way to go long term or am I better off with s tank and a coil or so inside to keep it hot? Tankless has long been touted as the better choice from an economics perspective...apart from the teenager factors of kids who won't get out of the shower until the water goes cold...a major problem with a tankless system.

 

[Sheepdog]

Man! I had no idea how this thread would take off! Thanks to all of you for some great insight. I just looked at a Kenmore electric 80 gal. hot water heater. They are about 500 clams, then you pay for install, lets call that another 500 clams for electrician and plumber. So let's say $1,000 to get it up and running. The government says it will use 4,622 KWH per year for average use, I have no idea how that compares to the reality of a four person family. But let's say it is close to accurate, and I pay 11.5 cents per KWH, it wil cost $531.53 to supply hot water for the year. It looks to me like year one I would save $484.47 by switching which includes the cost of the heater and the install, and it would pay for itself in 2.06 years.
Now, I know it will not supply the endless amounts of hot water my family is used to, however, if this limits my daughters showers to 10 minutes instead of their current 1/2 hour, my well will only work 1/3 as hard (less electricity) and my septic system will only have 1/3 the graywater to process(extended leach field life). I'm thinking this might be a really good idea. Does anyone have any thoughts on using the electric heater to prewarm the water then letting the boiler finish the job? This won't result in the same shortened shower phenomenon, but I think I should explore the option anyway. Also, does anyone know if you can replace the water the boiler heats to the heating zones with anti-freeze if the domestic hot water is done in the same boiler through a direct fire coil? Is there any chance of bleed over? Thanks!

-Sheepdog

 

[Jags]

Assuming $100 per month is cost for producing hot water using electric, how many gallons would this produce? So many variables come into play, makes this not an easy decision. I have a coil in my boiler that works ok for now. My electric rate is $0.20/KWH. Have never topped off the oil tank at end of heating season so oil usage is just a guess.

DC - the real point here is that I don't think a normal house hold could USE $100 per month of electrically heated water for normal household needs. Probably more along the lines of $15-$30 per month, depending on your utility rate, use, etc. Even if you went on the high side, and said $50 - it would probably be much cheaper than using $5.00 oil. That would be 10 gal. worth of oil, or a little over a quart of oil per day equivalent. Not sure many oil burners could do that for an average household.

 

[Sheepdog]

Something is not right here. Maine has some of the highest electrical rates in the country I believe. I am paying about 18 cents/KWH. Doesn't Illinois have lower rates than that?

Steam Man,

Check out Maine Interfaith Power and Light, you have a choice in Maine on who you buy your electricity from. CMP still delivers it but you can tell them where they have to buy your power. The price has gone up a bit since I signed my three year pricing contract at 11.5 cents per KWH, I just checked their website and todays price is "Maine Clean Power Hydro: $0.140 per kWh". Not only do you lock the price for 3 years, but it is all generated by a zero emmisions lo impact hydro plant which I think is in Lisbon Falls Maine, so the money stays here in Maine. They also have some other options but they are more expensive.

Disclaimer: I do not work for, represent or hold stock in any company associated with Maine interfaith Power and Light, nor do I know anything about their political or religious beliefs. I'm simply a happy customer!

-Sheepdog

 

[Jags]

Sheepdog, I replaced an old hot water heater recently with a 50 gal, energy star rated name brand with 10yr warranty for far less than the $1000 you were referencing. But I had all the piping and wiring in place to start with, so all it took was a little copper pipe, and a few solder joints to be complete.

I suppose if you had to start from scratch, and had the pro's do it, maybe your not that far out of line. Dunno. Its not a hard job though, if you are a handy kind of person.

 

[BrotherBart]

I can't believe anybody uses anything but electric water heaters. Zip maintenance. Yea putting in the breaker and the wire would be a few bucks, very few, but I have replaced our water heater with the new one and soldered it in myself. I had always been hesitant about sweat soldering a copper pipe joint. Looked on the web, got instructions and fifteen minutes later the joints were done and the thing was heating water. Piece of cake. And I am about the most craft impaired human on the face of the Earth.

To use a hundred bucks worth of hot water a month here at 14 cents a KWH we would have to plumb hot water into our toilets and outside hose bibs.

PS: The fifty gallon heater cost me $245 at Lowes and the solder was a buck and a half. That leaves a bunch of room for wiring costs between there and a grand.

 

[Sheepdog]

Sheepdog, I replaced an old hot water heater recently with a 50 gal, energy star rated name brand with 10yr warranty for far less than the $1000 you were referencing. But I had all the piping and wiring in place to start with, so all it took was a little copper pipe, and a few solder joints to be complete.

I suppose if you had to start from scratch, and had the pro's do it, maybe your not that far out of line. Dunno. Its not a hard job though, if you are a handy kind of person.

Jags,

Thanks for the info. it would take a bit more to install mine as it would be a completly new setup, but I can't imagine the costs would be far off if I figure on a grand for it. I am relatively handy, and I worked for my uncle who is a plumber when I was in highschool, so I might be able to pull off the plumbing on my own. I usually do all of my own electric work, with my fathers help he a EE. But, I'm not sure I want to try our luck with a water heater. I wouldn't wan't the first shower to be an electricfying experience! :lol:

-Sheepdog

 

[Jags]

I've always said with "fire and electricity" if you don't do it right, it will get you. If you feel that this is better left to a pro, than by all means, leave it to the pro's. That is the same reason the pro's installed my wood burner and stack years ago. Its not that I couldn't have done it, but a big steel box holding lots of flame inside of my house is darn well gonna be done right.

 

[Stevebass4]

:banghead: funny but i removed my 40 gallon electric hot water tank and installed an indirect hot water heater off my new burner - my electric bill came down by around 15 a month -

 

[steam man]

Something is not right here. Maine has some of the highest electrical rates in the country I believe. I am paying about 18 cents/KWH. Doesn't Illinois have lower rates than that?

Steam Man,

Check out Maine Interfaith Power and Light, you have a choice in Maine on who you buy your electricity from. CMP still delivers it but you can tell them where they have to buy your power. The price has gone up a bit since I signed my three year pricing contract at 11.5 cents per KWH, I just checked their website and todays price is "Maine Clean Power Hydro: $0.140 per kWh". Not only do you lock the price for 3 years, but it is all generated by a zero emmisions lo impact hydro plant which I think is in Lisbon Falls Maine, so the money stays here in Maine. They also have some other options but they are more expensive.

Disclaimer: I do not work for, represent or hold stock in any company associated with Maine interfaith Power and Light, nor do I know anything about their political or religious beliefs. I'm simply a happy customer!

-Sheepdog

There was an old post from this winter where the discussion of using fuel oil vs electricity. Electricity is the most efficient at converting energy to heat at the heat exchanger but when the you take into account the cost of producing the energy at the plant and transmitting it, it then becomes the most expensive. I checked out the average electricity cost comparisons for the country (I used Nebraska's study-they are the only publicly held power company). Maine ranked 46 most expensive at around 14.5 cents/kwh, Illinios was around #33 using somewhat older numbers. Prices have gone up since then. Sure you can buy the power here at 14c/kwh hour but what about the delivery/transmission charges? They bring my bill to .18 cents/kwh. I don't have this link right now but anyone can google it. I used a cost comparison calculator from a heating service in my hometown-try: (broken link removed) comparision.html. I calculated oil at 5.00/gal and found that electricity at 12.5 c/kwh is about even with oil. Jack that up to .18c/kwh and oil saves about $450.00. Believe me, electricity cost are going up along with everything else, including oil. I realize that any cost calculator can't take into account all the variables such as appliance efficiency, standby losses, time and energy in dealing with solid fuels, etc... I have a hard time believing anyone can use an electric water heater for $30-50/month. I can do a backwards energy conversion to figure out how much hot water that would be at various rates but it can't be much. You want to save some money? Go solar for DHW before Dec 31st. Get the tax credit for the installation and feel good about decades of free energy.

 

[BrotherBart]

I have a hard time believing anyone can use an electric water heater for $30-50/month.

With everything including the well pump in this house being electric and our bill never being over $79 when the A/C is off I would have a hard time believing that the 50 gallon electric water heater is using more than $30 a month in electricity. The 14 cents a KWH number I quoted is the average total bill with taxes and everything else divided by the total KWH usage. And our bill is within a few bucks a month of the average bill for customers of our electric co-op.

There are only two of us here but we are here 24/7/365 and I run my business out of the joint. With a whole bunch of computer horsepower running 16 to 17 yours a day.

I cannot see any way that having a boiler fire up every time you use some hot water can be economical.

 

[steam man]

I have a hard time believing anyone can use an electric water heater for $30-50/month.

With everything including the well pump in this house being electric and our bill never being over $79 when the A/C is off I would have a hard time believing that the 50 gallon electric water heater is using more than $30 a month in electricity. The 14 cents a KWH number I quoted is the average total bill with taxes and everything else divided by the total KWH usage. And our bill is within a few bucks a month of the average bill for customers of our electric co-op.

There are only two of us here but we are here 24/7/365 and I run my business out of the joint. With a whole bunch of computer horsepower running 16 to 17 yours a day.

I cannot see any way that having a boiler fire up every time you use some hot water can be economical.

My electric bill is never below $120.00/month and that is low. Typically it is around $140.00+. I also have a gas dryer/cooktop and heat/DHW comes from oil. I also use my woodstove to supply DHW in the winter. Flourescent lights too. No AC. I also have teenagers use a large amount of hot water, a number of computers and tvs, etc. In other words, all the things I can't control. The average house can use 30-60% of its total heating cost for DHW. My single elderly mom uses next to nothing in hot water so in the real world there are alot of variables to consider such as hot water use, initial investment, and payback. Like I noted, at about 12 cents/KW seems to be the break point for oil vs electricity but I also don't see electrical rates staying that low. I just watched an electrical generating representative say so on tv. Bottom line is that by the time power companies generate electricity and get it to your home, it is the least efficient method of heating.

Let's do the numbers-The maximum recommended hot water usage for a 2 bathroom home is 140 gallons/day. (I looked it up). Multiply that by 8.34lbs/gal to get 1167 lbs. 1 lb of water needs 1 BTU to raise 1 deg F. So to raise 140 gallons of water say from 50 - 120 deg F, you would need to multilpy 1167lbs x 70 = 81690 BTU's needed. There are 3413 btu's/KWH. 81690btu's/3413=24 kwh/day. Multiply that by 30 and you get 720 kwh/month. At $.14/kwh that is equal to $100.80 monthly bill. At my $.18/kwh for me that would be $129.60.

Do the same for oil assuming $5.00 gal at 85% efficient appliance and 140,000btu/gal. 81690 btu's/day x 30 = 2450700 btu's/month. 2450700btu's/119000 btu's/gal (at 85% efficient) = 20.6 gal heating oil. X $5.00gal = $103.00 total.

The last I paid was probably about $4.60 so my bill would have been about $95.00. Of course my bill doesn't include electricity to run the boiler but it isn't too much.

How much DHW do you get for $30.00/month? $30.00/.14 = 214 kwh. 3413btu/kwh x 214 = 730382 btu's. 730382btu's/70 deg rise for 1 lb of water = 10434 lbs/water. Divide that by 8.34lbs/gal = 1251 gals hot water. Divide that by 140 max gallons/day and that equals just about 9 days worth of hot water at max design usage. Divide it by 30 and you will have about 42 gallons/day.
I have seen numbers saying that the average house uses 20 gallons day/person. That seems low to me. I don't know how much you use but my whirlpool bath alone can use 30-40 gallons.

Less than .6 gallon oil/day for DHW. That's still not bad. I am still going solar.

If anyone wants to correct my numbers, feel free. I used 140 gallons/day from a plumbers design handbook. Of course less useage will change the outlook somewhat. Right about now my brain is overheating.

 

[Backroads]

if I figure an additional $100/mo elec to heat water, that's the same as 22 gal/mo using oil @ $4.50/gal.

I have a new electric water heat, electric clothes dryer, electric stove, electric oven, 1 fridge, 1 upright freezer and an industrial 3 x 3 x 7 ft. stainless steel beer fridge and air conditioners (window shakers). My electric bill is usually lower than $120 a month (not sure of elec. rate, but it is not cheap around here). Unless you have unworldly high electric rates, I doubt that you can USE $100 worth of hot water in an electric water heater per month.

Oh, let me state this. 3 adults ( 1 -19yr old daughter) and a little baby. Lots of laundry, long showers, and freekin' light switches that don't get turned off.

There is NO WAY heating water uses $100 a month. Like I said before, EVERYTHING in my house is electric with a family of 3 almost the same as Jags. I forgot we run the dishwasher also 3-5 times a week plus do dishes by hand daily. My wife ABUSES hot water like it's free. Our last two E-bills with two fans running in the last month have be about $110 each! That's for everything including the boys room where the light is only shut off when he goes to bed.

But I do have this to add, I totally agree it is a good idea through out the warm months to once in a while fire your boiler to keep it running smoothly and efficiently.

 

[begreen]

Stop the baths and take 5 minute showers with a low flow showerhead. You'll save a lot of hot water and will be just as clean. A good frontload washer will help too. Our total electric bill runs about $60-70/month for an all electric house, except a propane cooktop. That's with electric rates at about .09/kw.

 

[brider]

Based on the previous poster's quote of a Kenmore ave yearly kW estimate, my Connecticut rates would have me at around $970/year for
DHW, or I figure something over $80/mo.

I just checked my oil company's records for my oil usage the past 2 summers, when the boiler is only used for DHW, Both '06 and '07, very close to 30-31 gal/mo, which I figure at $4.50 gal these days is $135-ish/mo.

Elec saves easy $50/mo based on these figures, that would pay for a $330 Kenmore 55-gal Miser 12 (if I install it myself) in 7 months.

No-brainer.

 

[yukiginger]

I'm really enjoying this discussion because it's bugged the crap out of me the last few winters when I've been paying for gas to my home just for my hot water heater since I'm heating almost exclusively with wood and everything else is electric (dryer/stove/range). For only a couple months do I ever run the furnace (and then rarely) so many months I am paying just for the hot water only. The delivery charge plus the gas can equal $90 or more which seems crazy to me. If electric is cheaper I might go that way so I only pay gas in those months when I need the furnace to kick on.

Keep this going.

MarkG

 

[brider]

Just found this article, good for comparison purposes. it's dated 2004, the usage number is far lower than the previous poster's DHW ave amount from a plumber's handbook:

A recent study by the National Association of Home Builders (NAHB) Research Center concluded that the national average for hot water usage in homes is approximately 62 gallons per day or 22,630 gallons per year.1

Using 62 gal/day usage and the previous example's conversion factors, and my CT kW rate (total) of $.206/kW,
my monthly expense goes down to $66.78/mo! Quite a bit lower than the $135/mo oil-fired cost!

Obviously, the truth is somewhere in between. In my particular case, 3 little kids that get bathed usually every other day unless otherwise needed, 2-bath house, lots of laundry, I can't imagine my usage is too far off the NAHB number.

The only sure way is to install a water-meter in-line from my DHW source. My money says an elec heater is gonna save me money.

 

[Todd]

I'm really enjoying this discussion because it's bugged the crap out of me the last few winters when I've been paying for gas to my home just for my hot water heater since I'm heating almost exclusively with wood and everything else is electric (dryer/stove/range). For only a couple months do I ever run the furnace (and then rarely) so many months I am paying just for the hot water only. The delivery charge plus the gas can equal $90 or more which seems crazy to me. If electric is cheaper I might go that way so I only pay gas in those months when I need the furnace to kick on.

Keep this going.

MarkG

Ditto. I'm in the same boat. But I'm only paying $30-45 per month for gas hot water. I need a new water heater, but can't decide on electric, gas, tank or tankless. I'm leaning towards electric since it's silent running and doesn't need an air leaking exhaust pipe. But then there is the waiting between hot showers, gas seems to heat up faster?

 

[burntime]

Gas heats a lot faster. My winter bill for the water, dryer and stove runs about 35 bucks. Unless electric was insanely cheap I would stay with gas. Some preach the tankless units but I think they would burn out long before the break even point. Simple gets my vote.

 

[Thomask9590]

I would love to have street gas supplied. We have a gas main 300 feet from the house. The gas comapny will hook me up if i pay for the connection from the house to the main. 50 bucks a foot by the way. But my Brother in law heated his house with street gas for cheap money last winter.

 

[Sheepdog]

I have a hard time believing anyone can use an electric water heater for $30-50/month.

With everything including the well pump in this house being electric and our bill never being over $79 when the A/C is off I would have a hard time believing that the 50 gallon electric water heater is using more than $30 a month in electricity. The 14 cents a KWH number I quoted is the average total bill with taxes and everything else divided by the total KWH usage. And our bill is within a few bucks a month of the average bill for customers of our electric co-op.

There are only two of us here but we are here 24/7/365 and I run my business out of the joint. With a whole bunch of computer horsepower running 16 to 17 yours a day.

I cannot see any way that having a boiler fire up every time you use some hot water can be economical.

My electric bill is never below $120.00/month and that is low. Typically it is around $140.00+. I also have a gas dryer/cooktop and heat/DHW comes from oil. I also use my woodstove to supply DHW in the winter. Flourescent lights too. No AC. I also have teenagers use a large amount of hot water, a number of computers and tvs, etc. In other words, all the things I can't control. The average house can use 30-60% of its total heating cost for DHW. My single elderly mom uses next to nothing in hot water so in the real world there are alot of variables to consider such as hot water use, initial investment, and payback. Like I noted, at about 12 cents/KW seems to be the break point for oil vs electricity but I also don't see electrical rates staying that low. I just watched an electrical generating representative say so on tv. Bottom line is that by the time power companies generate electricity and get it to your home, it is the least efficient method of heating.

Let's do the numbers-The maximum recommended hot water usage for a 2 bathroom home is 140 gallons/day. (I looked it up). Multiply that by 8.34lbs/gal to get 1167 lbs. 1 lb of water needs 1 BTU to raise 1 deg F. So to raise 140 gallons of water say from 50 - 120 deg F, you would need to multilpy 1167lbs x 70 = 81690 BTU's needed. There are 3413 btu's/KWH. 81690btu's/3413=24 kwh/day. Multiply that by 30 and you get 720 kwh/month. At $.14/kwh that is equal to $100.80 monthly bill. At my $.18/kwh for me that would be $129.60.

Do the same for oil assuming $5.00 gal at 85% efficient appliance and 140,000btu/gal. 81690 btu's/day x 30 = 2450700 btu's/month. 2450700btu's/119000 btu's/gal (at 85% efficient) = 20.6 gal heating oil. X $5.00gal = $103.00 total.

The last I paid was probably about $4.60 so my bill would have been about $95.00. Of course my bill doesn't include electricity to run the boiler but it isn't too much.

How much DHW do you get for $30.00/month? $30.00/.14 = 214 kwh. 3413btu/kwh x 214 = 730382 btu's. 730382btu's/70 deg rise for 1 lb of water = 10434 lbs/water. Divide that by 8.34lbs/gal = 1251 gals hot water. Divide that by 140 max gallons/day and that equals just about 9 days worth of hot water at max design usage. Divide it by 30 and you will have about 42 gallons/day.
I have seen numbers saying that the average house uses 20 gallons day/person. That seems low to me. I don't know how much you use but my whirlpool bath alone can use 30-40 gallons.

Less than .6 gallon oil/day for DHW. That's still not bad. I am still going solar.

If anyone wants to correct my numbers, feel free. I used 140 gallons/day from a plumbers design handbook. Of course less useage will change the outlook somewhat. Right about now my brain is overheating.

Steam Man, That is the most indepth response I have EVER seen. :gulp: Man, you worked that one over! I heard that Anheuser-Busch makes a product to help cool the over heated brain, try one you deserve it. Anyway, thanks for the thoughts, I'm going to look at this a bit harder before I decide on which way to go.

-Sheepdog

 

[Redox]

Far be it to start an argument with steam man as he DOES know a lot more about hydronics than I do, but there is one flaw in your calculations relevant to this situation. The Sheepdog thinks he may be able to replace his space heating needs with a wood stove, thus eliminating all but his DHW from the equation. If he keeps the tankless coil in the boiler, his efficiency is not going to be anywhere near 85%. The standby losses on a hot boiler are enormous and I have heard a more realistic number is 25%. Replacing the tankless coil with an indirect heater will help a lot, but cold starting a boiler uses a lot of oil. The 85% number would only be appropriate if the boiler was already in use for space heating or you were using a lot of hot water continuously, like a laundromat or public shower.

I never thought I'd see the day that electric resistance would look like an economical alternative, but I think that day has arrived. Keep in mind that the delivered efficiency is near 100% on electric and only subject to the losses in the piping and jacket of the heater. If you bought the cheapest heater available and wrapped it with additional insulation, it will stay hot for days. Insulate the piping and you will be even better off.

Tankless (instant) electric heaters really only eliminate the loss in the piping, assuming that you install it near the point of use. Tankless gas eliminates the standby loss of the heat up the flue. Instant electric heaters need a lot of current to keep up with a shower and can only keep up with one user at a time, unless oversized. Instant water heaters in general are about twice the price of their equivalent storage counterparts and will take a long time to pay back, IMHO.

I think the best bang for the buck is going to be the electric storage water heater, properly insulated. I would not pipe it in series before the boiler as you will have to heat the boiler up to get hot water. You could pipe it in series after the boiler as a preheat and only turn it on if you expect an unusually large need for hot water, but this may lead to rust as the cold water will probably make the boiler sweat in the summer. If you are really trying to idle the boiler, cut the DHW coil off and abandon it. You can always reconnect it in the future if economics dictate. Draining the entire boiler is probably going to invite additional rust and corrosion, unless you could purge it with nitrogen or something inert and seal it up good. I wouldn't recommend putting glycol in the system unless there is a danger of freezing in some of your more remote zones. In addition to being expensive, glycol will show up every tiny little leak in your system that wasn't a problem before. Replacing the nozzle on the burner only goes so far as it will hurt your combustion efficiency firing into an oversized chamber, much like an oversized wood stove doesn't work as well with a smaller fire. Most boiler manufacturers only recommend a 25% derate before efficiency starts to drop off. Cold starting a derated boiler is even worse as it takes longer to hit a clean burn. I also don't think leaving the boiler cold for an extended period is a big deal as it is the thermal cycling that stresses the connections and seals.

FWIW, we just received a few bills this week that may interest a few folks: Water was about 150 gal/day last quarter and gas is averaging about 50,000 btu/month for DHW, cooking and clothes dryer for a family of four rather economical people.

Sorry for offering an opposing viewpoint, but I think it's valid. One final opinion: Never start a plumbing project when the hardware stores are all closed!

Humbly submitted,
Chris

P.S. This thread really belongs in the Boiler Room, but I suppose I've put it in the Ash Can now...