Gas vs electric H2O heater costs?
We had intended to have a gas (propane) hot water heater in our new house but the increased costs of petroleum products gives us pause. What are the pros and cons these days?
We had intended to have a gas (propane) hot water heater in our new house but the increased costs of petroleum products gives us pause. What are the pros and cons these days?
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Replies
Check with your electric utility and see what rates and plans that you have.
They vary ALL OVER THE PLACE.
Can be somewhat cheaper to much more expensive.
If you go with gas, make it a direct vent model. Safer that way and you don't have to worry about make-up air or backdrafting.
Gas hot water heaters have quicker recovery time than electric and many operate when the power is out. Propane seems pretty inconvenient though unless you have a large tank that supplies other equipment.
I just spoke with a plumbing house about this ,and ALL of the gas units he sells will not work (electronic ignition), if the power is out.
the guy gave me the impression that he did not care for that feature, but he has to sell what the manufacturer is building.just one more thing to put on emer power I guessPersonally I had too many problems with Electric I changed the lower element three times in three years with one unit from Amer Standardso never again, Tom"
Interesting... thanks for the info.
I mean a ROYAL PITA"
"...ALL of the gas units he sells will not work if the power is out."
You'd have to ask an electrician to be sure, but I don't think the electric models will either.
(-:
When you go to court you are putting yourself in the hands of 12 people that weren't smart enough to get out of jury duty.
ooops a mistake on my part Boss, I googled everything pertaining to everything and you are right,,,,LOLelectric would need a really really BIG emr. generator"
Another thing with the electronic flame igniter........
When you leave for vacation and turn off the gas line, also unplug the heater, or else it will continue to try to ignite while you're gone. I'd expect it could shorten the life of the element.
..........aaah modern technology ,
thanks for the good tip"
As BH said, check the rates for your local utility.
However, as rates for petroleum & natural gas increase, then the cost of electricity will rise as well - electricity doesn't come from the air.
No, it comes from coal, hydro, and nuke.In addition to gas and oil.That is why there is they wide variation in rates now.They vary from under 3 cents (increment and/or time of day) to 15 cents and maybe higher.
Our local gas & electric company (LG&E) has a current-price comparison (gas vs. electric) for water heaters, furnaces, etc.:
http://www.lgeenergy.com/rsc/lge/res_heating_costs.asp
Right now, in Kentucky, it costs about 30% more to run an electric heater. It also takes longer to heat up the makeup water.
However, there has been recent speculation that natural gas costs will triple vs last year. Electric prices (around here anyway) are not nearly as volatile as gas. I've been tracking energy costs for a few years. Gas is going up, electric stays about the same.
Note that this chart may not be 100% accurate. There are recurring monthly service charges that I tried to remove from the data, but I may not have been successful.
Lew
Another reason to consider propane over electric is relaxed energy codes. We recently adopted the IRC here in Western Washington, but up until then at least, you were allowed a far higher glazing/square foot ratio if heating with gas instead of electricity. And like anything else, the more you buy, the cheaper per gallon (or pound). So even if it's a push price wise, it might allow you to live in a brighter house, not to mention the potential solar gain.
If natural gas goes to $16+/mcf as projected this Winter, then electricity at 6.5 cents per kwr or less will be competetive. Heres a chart and spreadsheet that compare the cost for various fuels. The efficiencies for non-eletric appliances will affect the cost somewhat.Maybe we all need coal-fired water heaters ;-)
I'm pretty sure the original furnace in "this old house" was coal-fired. I'm pretty sure that I'm glad it's been updated (current boiler is 2-yr-old NG), but I may look into a wood-burning stove. Of course then there's the issue of makeup air...
There are direct-vent pellet stoves that solve the problem of make up air. It's sad that the price of natural gas, a fuel that used to be relatively cheap, is now going through the roof because most new power plants don't burn coal.
Why do you persist in living in the past. The obvious way to heat water is through a solar hot water system, with an on demand (Bosch?) gas/propane heater to top it off. Sure its an investment. In the future... In your childrens world. Oh I forgot you dont believe in the Kyoto accord. Just as long as you can keep dumping coal pollution in the atmosphere!!!!
Go to homepower.com. Read a progressive (US) magazine that talks abouy conservation and technical innovation. And don't worry, those folk are also about conspicuous consumption
so you won't be forced to up the minimum wage and actually pay someone a living wage, or god forbid, health benefits.
Since I've never met you, and we've not exchanged a single word in conversation, it's interesting that you seem to know all about my views on the environment and even my political leanings.Do me a favor and bugger off.
Nah, nuclear is the way to go. Nice and compact (if you dispense with the shielding) and very low operating costs.
If ignorance is bliss why aren't more people
happy?
If the tank is big enough, say about 50,000 gallons or so, the water would provide the necessary sheilding. Although, that does make it a little less compact.
Maybe a used submarine reactor would do the trick- sealed sodium closest to the U, steam to generate electricity for the neighborhood, and hot water co-generation. I toured Hanford quite a few years ago, and they had around 30 old sub nuclear reactors sitting out in a big field- they couldn't bury them or anything, they had to be in a place that Russian sattelites could keep count of them.zak
Heck, if you live on the coast just have them beach the sub next to your house.
If ignorance is bliss why aren't more people
happy?
Not at all obvious to me. Have you figured out what the payback time on the tankless water heater is? If solar provided 80% of your hot water, you are talking about the difference between gas (or propane) and electric for the remaining 20%. Sounds like a waste of resources to me.
...............if you align your emer. gen with the earths magnetic field ..........you get free power...just kidding"
I've heard of people who live near high tension power lines burying (sp?) a coil & getting juice that way since it induces a current in the coil.
Definitely illegal.
...........you're killin' me....."
A friend of mine used to live on a rather large piece that had high tension power lines running behind his property. He said that whenever he was mowing the hairs on his neck would stand up whenever he was near the back fence. One time he said he jumped off to pick up something that was in the way & when he went to climb back on his tractor, he got a nice little shock.
...Ok, that's more like it.....,,that other business about the coil, politely tell your friend that there are other ways to try and kill himself !!!"
A buried coil to pick up induced power from high-voltage overhead lines? How about a coil on poles up closer (but not TOO close!) to the overhead lines? That would pick up more power.I would like to hear from someone who did this - what was the coil size, number of turns, wire size? What was the high-voltage line carrying - voltage and current? AND...just how much voltage and current were you able to pick up?And now, the fun part - that radiated power must be going through your body and inducing...what?...in your body. - Jim - all too curious electrical engineer
Depends on local rates. Usually if you have natural gas it's a slam-dunk in favor of gas, but with propane it can depend.
Ask both propane and electric suppliers for their cost analysis for water heating. Of course they will both favor their own product, but that will give you a feel for the margins.
(Also, often the electric co will give you a reduced rate for water heaters if you have a timer or demand switch installed on it. This may mean no large volumes of hot water during the day on summer days, but can save a lot of money.)
Gas generally is faster heating and can have a higher gal/hr capacity for its size. Plus you don't have to have quite as big an electric service, if that might be an issue (probably not). The electric heater is generally cheaper and will last longer.
Whatever you buy, spend a few more bucks and get a higher efficiency model. For electrics this just involves better insulation, but for gas there is quite a range of efficiencies depending on burner design, induced draft, direct vent, etc.
Edited 9/15/2005 9:24 am ET by DanH
As others have said, it depends on the propane vs. electricity costs in your area. In most of the US, propane would be much cheaper. In addition, the propane heater will give much better performance in terms of recovery.
If you send me a PM, I will forward a copy of a paper which gives the equations to calculate energy savings as a function of fuel costs and energy efficiency.
Bill
PS...since most of the residential natural gas (propane) water heaters we sell have no electrical connection, they continue to function when the power is out. The models with fans and/or blowers will not function...obviously.
limeyzen,
Most have pointed out various reasons to select one over the other but one point to consider that has not ben brought up so far is that propane needs to burn air. the air that is already in the house and conditioned (either heated or A/C'd) while some models offer forced exhaust I know of no model which draws outside air in the way efficent furnaces do.
Thus 24/7/365 there is this great big old air sucking appliance.. using up heated (or cooled air) Electric units don't use air and thus don't need to suck warmed or cooled air to work..
The question thus is more complex.. it's not just purchase cost, plus energy costs. It's purchase price, plus instalation price, plus energy costs and energy loss. I've never gotten an answer from this forum or any other forum how much energy is used with that 4 inch duct sucking air out of the house..
The draft heat loss for a high efficiency gas unit is negligible. Direct vent would be essentially zero.A point on the side of electric, though, is that it can be installed essentially anywhere -- no flue, no venting needed, essentially zero clearance. And where small units are wanted (eg, remote units in distant bathrooms) electric is much more manageable.
As I understand it, high efficiency units have a double-pipe flue. The outer pipe pulls in fresh (i.e., un-cooled or -heated) air from the outside for combustion, then exhausts the flue gas through the inner pipe.
Two added benefit of this arrangement:1) The fresh air is heated, slightly reducing the amount of fuel required to burn the air, and2) The flue gas is cooled, making the external venting requirements less stringent. You basically just blow it out the side of the house instead of out and up, and you can use PVC instead of metal.
Lew,
I've looked all over for such units. basically all I can find for water heaters is the powered vent type that you can do the same basic thing to (Side vent) . But they don't provide outside makeup air..
The reason according to the HVAC guys I speak to is that incoming minus 35 degree air could freeze it..
Frenchy,
Take a look at Bradford-White Power Direct Vent Water Heaters. Models PDX2-*. There is a 50 gal (48)/60,000 btuh, 65 gal/65,000 btuh and 75 gal/70,000 btuh versions available.
The "HVAC guys" with which you spoke need some more information. These units work just like a sealed combustion furnace or boiler, all of which do not freeze due to cold combustion air.
Tim
Does the unit you mention have two pipes? one for fresh air intake and one for exhaust? I can imagine that if the exhaust were large enough to work like a direct vent gas fireplace they could get by with a pipe within a pipe kinda deal.
I Visit new homes all day long anywhere from 6 to 30 homes a day and have yet to see a gas water heater that has a sealed combustion chamber.. (and I visit some really high end homes)
I did see a Boiler with sealed combustion chambers but there was a suplimental electric heateracting as standby heat and part of the system had a digital pad that would turn on the suplimental heater if the water temp dropped below 40 degrees..
Very high end european model.. can't remember the brand..
Yes, the unit has separate flue exhaust and combustion air intake pipes. Take a look for yourself at http://www.bradfordwhite.com/pdfs/residential/102.pdf
What you describe is a direct vent WH and they are not nessecaryly high eff.And they are all realavitely close vented (relativley short distances between the WH and the vent). And I believe that all of the venting is metal.Now there are those that are boosted vent with a van. And I think that some of them mix in enough air so that they can use plastic.Most of those use ambinent air.Don't know if are setup for sealed combusition or not. But if so that would be a separate pipe.
"As I understand it, high efficiency units have a double-pipe flue."
I haven't seen one yet that has 2 pipes. I own 2 direct-vent water heaters, and they both only have one PVC exhaust pipe.
Personally, I would prefer the 2 pipe system. Just don't know if anyone makes one like that.
Two things are necessary for important tasks: A plan, and not quite enough time
"I haven't seen one yet that has 2 pipes. I own 2 direct-vent water heaters, and they both only have one PVC exhaust pipe."Are you sure that they are direct vent or are they power vented?Direct vent have an elbow off the top and turn towards the wall and exit in a termination. Fairly limited in how far they can extend either up or out.Here are 3 styles.http://www.hotwater.com/RESIDENT/rgpowerhouseseries.htmThe last only is the only pure Direct vent. And it uses double wall pipe.The other two are power vented. The first one is a power direct vent.
Edited 9/19/2005 11:04 am ET by BillHartmann
"Are you sure that they are direct vent or are they power vented?"
They're power vented. (The 2nd one in your link) I just used the wrong term.
You can't expect me to be this good looking AND know what I'm talking about............................(-:
Looks like the first one in your link is a 2 pipe power vented system. That's what I wish I had gotten...
Everyone has a photographic memory. Some just don't have film.
"You can't expect me to be this good looking AND know what I'm talking about............................(-:"Well zero for zero is a PERFECT record <VBG>.
There are lots of direct vent systems that use a coaxial flue. Here is one I'm familiar with:http://www.wallhungboilers.com/products3.htmlMany building codes require direct vent (100% outside air for combustion) for gas appliances installed in living areas, especially basements.
It depends on your climate. Here in non-freezing country, the WH typically is outside the conditioned envelope, and uses ordinary outdoor air for combustion. Sometimes they sit on a back porch with just a sort of sheet metal shed over them.
-- J.S.
A lot depends on the relative prices of equivalent amount of energy between gas and electricity.
A lot also depends on the particular model or modifications, in some cases, which are used. Gas has been historically cheaper. It also heats water faster so you get more. How much this matters depends on how long the showers are and how many people take them.
The weak point in a gas unit is the flue and pilot light. The flue tends to allow cool air to bypass the insulation. Some gas units have a damper to limit this air flow. Some use a small electric motor to drive this and these also tend to seal tighter. Mostly this is seen in commercial and high efficiency units.
The pilot light eats power 24/7. Its costs add up over time. Some higher end and commercial units eliminate the pilot light but this increases the initial cost, the complexity of the unit and makes the heater dependent on electrical power. Most of these ignitors don't need much power so a UPS, Uniteruptible Power Supply, which supplies 120v power from a battery, may be an option. Even a small 600vA UPS can last for a long time on some of these ignitors. If the UPS also has to power a damper motor it won't last as long but it may be possible, for emergency use while the utility power is out, to lock the damper open. This would slightly increase gas usage.
Electric units are relatively efficient. 100% at heating the water. Which goes down with heat and line loss. The weakness of electrical units is that, in an emergency electrical power may be difficult to get and too precious to use to heat water. On the up side an electric unit is easy to add insulation to. It is hard to insulate a gas unit because of the need that is breath. An electric unit can be freely smothered in insulation. Which can greatly decrease the standby heat loss.
Electric units can be located nearly anywhere. Under counters, in an attic, in a crawl space walled into the corner of a closet. It doesn't need to breath so there is not need to poke holes in your well insulated building shell.
Electric water heaters are easy to repair. Stock up a couple of spare elements, a thermostat and anode and your set for a long time. Gas units are rugged and reliable. Watch how you set the thermostat and maintain a good ground and your pretty safe. Probably a bit more reliable than the electric ones but repairs can be difficult and expensive. Failure to set up pilot loss or over temperature controls correctly or a leak can cause a fire or explosion.
While you're at it, you should look into tankless propane heater with electronic ignition. When I switched from an electric heater to the tankless, my utility bill (electric) went down more than the cost of the propane. If you get a heater with a pilot light, your savings will be reduced (how much? I don't know).
Yep, when the power goes out both electric and propane (with electronic ignition) won't do squat. They both will just sit there. However, with a pilot light tankless, you'll be bathing/showering while your neighbors are getting grungier by the day.
butch
I have a Rinai propane tankless, direct vent, and it uses the pipe within a pipe for intake and exhaust. Compact, efficient, but not cheap to purchase. I love it, but my wife thinks the delay in getting hot water to the kitchen sink takes a little getting used to.
Mike-
That Rinai propane tankless, how much did it cost you?
r u a feckless dastard?
$1100 I think. But since my house is used intermittently for much of the year, I figure I'll probably save a bit on fuel costs. It should also last far longer than a tank unit, and takes up no floor space as it is mounted high on a wall. It also makes it easy to winterize the place.
Mike
Thanks for the reply.
r u a feckless dastard?
Alot of interesting feedback on this I see. Gravity vented units will work without power & the new codes makes all of the units with sealed burners & since steel is at an all time high the price on gas fired water heaters has more than doubled in the last two years. Gas does heat more quickly than electric & energy cost have always been roughly the same ratio so untill they come up with really cheap electricity gas is the better option.
"& the new codes makes all of the units with sealed burners"They are not sealed in the HVAC sense. That is they don't bring in outside combustion air.They use inside combustion air. What they do have is a flame arrestor type of feature that is suppose to prevent it from igniting funes.
Yup very true. I'm not a big fan of the magnito hangin off the unit I prefer to use my torch to light the pilot cause it's a good flame & it preheats the thermo coupler.
To Limeyzen: Sorry this is a few months out of date but still pertinent I think.
Your discussion with those so called "Professionals" is strictly stone age! Why do you persist in living in the past. The obvious way to heat water is through a solar hot water system, with an on demand (Bosch?) gas/propane heater to top it off. By 1992, Austria had over 200.000 domestic hot water systems installed. Sure its an investment. In the future... In your childrens world. Oh I forgot you dont believe in the Kyoto accord. Just as long as you can keep dumping coal pollution in the atmosphere!!!!
Go to homepower.com. Read a progressive (US) magazine that talks about conservation and technical innovation. And don't worry, those folk are also about conspicuous consumption
so you won't be forced to up the minimum wage and actually pay someone a living wage, or god forbid, health benefits.
Not much zen there I'm afraid.
Regards George Washington.
""Professionals" is strictly stone age!" Who in that discussion claimed to be a "professional" and if so what proession?And what PROFESSIONAL credentials do you have?"Oh I forgot you dont believe in the Kyoto accord."How do you know that? It was never mentioned in the thread."so you won't be forced to up the minimum wage and actually pay someone a living wage, or god forbid, health benefits."Wrong place for that discussion. It belongs in the Tavern.