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Wood Pellets vs. natural gas furance

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Mike49024, Jan 12, 2011.

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  1. Spartan

    Spartan Member

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    In order to cross check my previous calculations, I'll use my original numbers. Since the US and Canadian dollar is almost at par, I wont worry about US and Canadian monopoly money.

    I therm is 100,000 BTU therefore it's 2.8169 times .33 or 93 cents.

    I ton of pellets at 8900 btu per pound is 17,800,000 btu.

    Therefore.......17,800,000 per ton divided by 100,000 per therm is 178. Times that by .93 is $165.00 per ton.

    Further.....

    93 cents per therm DIVIDED by the efficiency of a gas furnace is 93 cents divided by .9 equals $1.03. In other words, I have to pay $1.03 to get ONE therm into my house.

    Now what is the cost in ngas taking into account the ngas efficiency? 1.03 times 178 therms equals $183.00 per ton.

    Now what is the pellets burners efficiency? Assuming 80% efficiency if we were to convert that into actual heat? $183 divided by .8 equals $146.40. In other words, we took $183 worth of ngas therms, shoved it into the pellet burner and got out $146 of heat. That is the break even point.

    ~~~~~~~~

    Where the difference lays with your calculation is....you took 16,500,000 BTU per ton.

    Therefore......16,500,000 is 165 therms times .93 is $153.45 per ton.

    $153.45 divided b .9 gives for a 90% ngas burner costs me $170.50 of actual output.

    $170.50 multiplied by .8 for an 80% efficient pellet burner and I get $136.40 cents of heat.

    Not much different from your price. You took a lower value for the BTU output of your pellets therefore the ton of pellets have to be an even LOWER price them my original estimate to break even with ngas.

    Again, this is off the top of my head.

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  2. jgcable

    jgcable Member

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    Same exact thing here. It would cost me considerably more to heat the house insufficiently with pellets then it does with natural gas.
    With pellets (and my main heating system off) I get an ice cold finished basement and a semi cold fairly uncomfortable 2nd floor.
    With natural gas fired steam radiators I get a nice uniformly heated house.

    I have come to the realization that I am forced to use my pellet stove insert as a space heater and I can't expect it to heat my entire house or help me much on my gas bill. I am ok with it now but it was disapointing at first.

    My buddy has a fairly small wood burning free standing stove with no blowers or anything in his 2 story colonial and he hasn't even turned his oil fired forced air furnace on this entire season (Connecticut) and he keeps his house in the mid 70's. His upstairs is so hot he sometimes has to open the windows.
  3. Spartan

    Spartan Member

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    It would be nice to see a standardized test. So far, I read about 100% burner efficiency and I'm not sure what the heck they are talking about. Sure, you burn all the pellets but how does that translate to how much heat comes out of it? Or goes up the chimney?

    One big hint of number fudging is the size of the fan. In order to move 75,000 BTU, my furnace has a 1500 cfm blower. A well known pellet stove insert has 160 cfm blower to move 40,000 BTU. I don't care how much radiant heat they claim comes out of it, the amount of CFM simply does not make sense. On the other hand, nobody is going to sit in their family room with a 1000 cfm fan blasting through the insert.

    Don't get me wrong, I LOVE to stick it to the oil and gas companies, but my wallet wins all the time.

    Last but not least.....

    The pellet stove manufacturers have jumped all over this CO2 malarkey. Ten year ago, municipalities were trying to stop wood burners because they polluted. Now they are no longer called wood burners, they are "biomass" burners and they are environmentally friendly and CO2 neutral. Bad for you then, good for you now......and some of the sheep nod.


    P.S. The only reason I'm looking at pellets is to use the waste material I have.
  4. ChrisWNY

    ChrisWNY Feeling the Heat

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    Well, you can certainly tell with a pellet stove that a lot more heat goes up the flue than what goes out of the exhaust PVC vent of my LP furnace (which has a 92% AFUE). During combustion, the PVC vent coming from my furnace is barely even warm to the touch, whereas the PL vent from my pellet furnace is a good 120-150°F. It's no wonder that most pellet burner manufacturers don't disclose anything about AFUE ratings of their unit, nor do they bother to obtain such a rating (as I don't believe it's required, nor would they want it published because it would hurt sales, especially with uneducated customers). The average customer is usually not well educated on the product they are looking to buy, so they walk into a hearth shop looking for a pellet burner to replace or supplement their existing gas or oil furnace. They know their gas furnace has > 90% AFUE, then they see a 70% AFUE on a pellet stove, in most cases the sale would be lost then and there. For the educated customer, they realize the benefits of burning pellets vs. oil or gas, and the fact that a decent pellet stove or furnace can provide excellent localized heating, rather than having a 150K BTU furnace kick on to heat the entire house when the temp on the first floor drops below the thermostat threshold (which is set a temp that makes the living room comfortable, the drawback is that your bedrooms are being heated up as well when you're not even using the room).
  5. Spartan

    Spartan Member

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    There would be NO sales if you add the labor into it. Nobody who uses gas can justify pellets unless they have a hang up about safety.

    You ever wonder why the EPA screams about coal and wont mandate AFUE ratings? Ever wonder why they are now "biomass" burners and not "dirty wood burners"?

    It's come to the point where politics overrides common sense and reality.
  6. chris288

    chris288 New Member

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    My house is 2 br, 1,100 sqft, single level ranch, semi open floor plan with electric heat. I use the XXV as a sole source of heat, the electric NEVER comes on, stove is at one end of the house in the living room, as you move down the house it progressively gets cooler. LR is kept ~ 71, dining room goes down to 70, kitchen 69, back of the house 68, one BR closed off and the MB is usually around 66 but is fine for sleeping. Been burning pellets for 14 years, I certainly know if I had a 2 story or a larger house and tried heating with pellets that some parts of the house aren't going to be heated very well and in some cases down right cold and would need to be supplemented with some other kind of heating source.
  7. RiddleMasterMorgon

    RiddleMasterMorgon Member

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    I would suggest to google here and use their excell file to compare heat sources:

    www.eia.doe.gov/neic/experts

    This seems to me the most accurate list I have seen, confirms my own tests in my house. Electricity/Oil/Propane are the higest costs to heat, Wood Pellets, Corn, Wood is second and Coal/Natural Gas the cheapest. There are some exceptions such as geothermal - but quite expensive in the initial investment. Of course regional influence is possible and the design of your house plays into it as well. If you have an open floor plan Wood Pellet Stove works bit better for you, if you try real zone heating with electricity its not as bad ect. If you want to dream a little bit, go geothermal with radiant floor heat and get the electricity you need for the pump from solar cells and wind energy (completly ignore initial install costs for a second).

    For my area and at this time the wood pellets are about equal cost to heat my house than oil is (most people don't want to hear that). If the oil price goes above 4 USD/gallon the coin flipps - and that will not be too far away. For natural gas the cost will likely be stable for some years to come IMO. There is a hype around wood pellets that is quite irrational when it comes to the question of what heats my house for minimal buck. That said there also is the argument of 'green' and 'oil independance' - for some thats an argument, for others its not.
  8. Countryboymo

    Countryboymo Feeling the Heat

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    My Castile that is sitting in my basement won't heat the house without the heat pump or heat strips helping but I didn't buy it solely for that purpose. I have a 15 seer heat pump and staged heat strips so I only really 'save' money running the pellet stove if it gets below 20 degrees. If the power goes out it and a small generator will do an incredible job keeping the basement warm and the water lines in the house from freezing. I purchased my stove to save some on strip usage but mainly for a back up source and ambiance. I also like to have a toasty spot to hang out when its super cold.
  9. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Your link results in:

    Directory Listing Denied
    This Virtual Directory does not allow contents to be listed.
  10. chris288

    chris288 New Member

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    I heat my house on 1 40 lb bag / day costing ~ 4.00, there is no way in the world I could heat my house on 4.00 worth of oil / day, please explain your reasoning ?
  11. becasunshine

    becasunshine Minister of Fire

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    We had our pellet stove (Napoleon NPS-40) installed in late summer 2008 after a significant rate hike by our local NG supplier. Since then, the economy has further unwound, taking energy commodity prices with it. I understand that natural gas has been somewhat disconnected from the oil market since, apparently, those deposits can exist and/or be harvested separately from retrievable oil deposits, and that there is, apparently, an abundance of NG in the U.S. and Canada.

    Not long after we bought our pellet stove, we heard that our local NG provider signed some sort of long term agreement with a regional provider, thus supposedly insuring reasonable NG prices over the long horizon. This was after the rate hike, and I have a hard time keeping track of everything that happened in that short period of time. I do remember that I was kicking myself for the pellet stove/pellet purchase until we received the next NG bill, which included our budget billing amount for the upcoming winter season.

    Even though NG prices were depressed, and our provider had signed onto this cost-saving agreement with the regional provider, our monthly budget billing amount jumped by $25/month. I know that doesn't sound like a lot of money, but $25/month was a 33% jump in our budget billing amount. Obviously we didn't have a large NG bill in the first place- but we were pretty draconian about the household temps. We kept the HVAC thermostat set at 65'F during the day and 55'F at night. And for this our budget billing amount goes up $25 a month for the next winter? No thanks.

    $25/month is also a ton of pellets, and we use two tons of pellets a year.

    We cancelled our budget billing arrangement and went back to standard billing, in which we are billed each month for the amount of gas we used in the preceeding month.

    Our house is a circa 1958 1428 sq. ft. brick and block bungalow with a single story circular floorplan. We rely on our pellet stove as our primary source of heat. The pellet stove does a fine job of keeping the entire house warm when temps are in the 30's or above. Once we hit the mid-20's we can feel the temperature gradient drop off on the side of the house that's farthest from the pellet stove. At 20'F or below, the NG furnace cuts on once or twice a day, usually in the early morning and sometimes again in the evening, to help maintain the temperature.

    Last winter and this winter have seen record cold temperatures- and we have yet to pay a NG bill for actual gas used that is as high as our proposed budget billing amount for the 2008 heating season. And the house is warmer, to boot. We now keep the HVAC thermostat set at 68'F during the day, 65'F at night. The furnace cuts on maybe once or twice a day to help the stove maintain these temps if it's really, really cold outside.

    The zone heating or space heating aspect of the pellet stove may help us in this regard. Some of our older baseboard registers no longer close properly, making it difficult to shut off the heat to our spare bedroom. We've looked into replacing the registers, but they are a different size than what is available on the shelves today. We'd either have to have replacement registers made to order, or we'd have to splice/replace the baseboard trim around the new registers (and perhaps patch hardwood floors as well.) All in all it's a lot easier to just shut that door and sent the pellet stove heat past that room into the rooms we are using.

    Last year we paid $487 for the entire year for natural gas to heat our water and for the natural gas furnace. We paid approximately $560 in pellets. This equals an annual heating/hot water cost of $1047- which, if averaged over 12 months, is still less than our proposed budget billing amount for 2008.

    Assuming that our budget billing amount stayed the same as it was quoted in late summer 2008, we would have paid $1200 for the year in natural gas, and we would have spent the past two years in a significantly colder house.

    Less than a $200/year savings is not a huge amount, hardly worth it. I can't disprove a negative but I am skeptical that our budget billing amount for our natural gas bill would have remained at the 2008 amount over two of the coldest winters on record.

    Three more aspects that I haven't seen anyone mention in this thread:

    1. It is possible to buy pellets many months if not seasons ahead, so one can lock in today's price (for better or worse) for next season's heat. As far as I know it's not widely possible to buy one's natural gas ahead of time.

    2. If one has the ability to store pellets at home, then one knows *exactly* where one's heating fuel is located. There's something to be said for warmth security. :)

    3. My cat *loves* the pellet stove. :)

    I realize that the rule of thumb is that natural gas costs less per BTU than pellets, but I thought this "real world" example might be worth another look. Also, I haven't analyzed the "delivery" costs on our NG bill, nor have I looked at it closely re: taxes, fees, additional costs, etc. Are you guys figuring in the "extra" expenses associated with natural gas in the cost per BTU? Against that I guess I'd have to figure the cost of hauling the pellets back to our house by one means or another...
  12. Spartan

    Spartan Member

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    In my two cost analysis, I used the bottom line including taxes for the ngas. I did not include taxes on the pellets because I don't know if in the US, the state/federal levels tax pellets. And if they do, I don't know the rate.

    Up here, they tax everything and then tax the tax. They are about to introduce Eco-Sanitation and Exhaling Tax. That's where they can charge us by the breath, the flush and the content.
  13. checkthisout

    checkthisout Feeling the Heat

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    With Fees and all, the local utilty here charges $1.00 per therm.

    Pellets @ $187.00 a ton = ¢.95 per therm.

    As some have stated, no way are these pellet appliances approaching the same heat exchanger efficiency as a an NG furnace even though Travis is claiming 8000 BTU's @ 1 lbs per hour for mine I just don't see how that's possible.

    Anyways, in the wholesale natural gas is waaaaaayyyyyyy cheaper but once all the fees are added in are you're about the same if not worse with the pellets.

    As far as pellets being environmentally friendly or making us oil independent, well nearly all of us are getting them from stores where they have traveled at least a few hundred miles on a big rig burning diesel at the rate of 5 MPG's. Plus wood smoke isn't the most healthy to breathe no matter how efficiently the fuel has been combusted.

    With that said I still love my stove. :)
  14. becasunshine

    becasunshine Minister of Fire

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    Yeah, I agree on the energy consumed in making and transporting pellets. Pellets are "green" in that we are burning what would otherwise be waste products, but in terms of energy expended and expense to produce, ship and even consume it's not a zero sum game.

    Pellets aren't cheap here in central VA. I've shopped and shopped and shopped, including pricing direct from the factory. Factory direct is the best price, but getting the pellets home becomes the issue and the expense. We are not equipped to accept a shrink-wrapped pallet of pellets and get it home in either of our vehicles, and as of the last time I checked, the factory isn't offering home delivery at all, even for a fee. We'd have to rent a truck, which would mitigate our cost savings. So far we haven't done that (yet.)

    We have to negotiate a price per ton that includes delivery, or purchase from a vendor who is local enough that it's cost-efficient and time-efficient for us to pick up several bags at a time from our "tab." We've done a little of Column A, a little of Column B. Since 2008, three burn seasons, our price per ton has ranged from $265/self-serve to $280/delivered. So far, local Big Box and chain store retail vendors haven't offered prices that are any better.

    I guess it's saying something for our local NG prices when $265-$280/ton for pellets is even competitive. I *wish* I could find $187/ton here.

    I'm looking at my records and I don't think I've been charged sales tax on any of my pellet purchases here in Central VA. YMMV.

    I'm kinda holding my breath to see if natural gas fueled automobiles take hold. I suspect that if that happens, the increased strain on supply will cause natural gas home heating costs to rise. At this moment it looks like more emphasis is being placed on electric cars. (I will own an electric car, oh yes I will, as soon as the purchase price becomes bearable.)

    All this being said, I like having several different ways to heat the house. Right now we have a NG furnace and a pellet stove, and if all else fails (the power is out) we have a kerosene heater and a little propane heater as fall-backs.

    I'd love to have a wood stove but the layout of our house is not conducive to placing a wood stove in any of our rooms.
  15. jtakeman

    jtakeman Minister of Fire

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    Most of the stove manufacturer's do that. Its not the BTU output there claiming. Its the BTU input. Deduct the stoves efficiency and you get the estimated output of the unit. Some stove manufacturer's have started to list both the input BTU's and the estimated output BTU's. Most of the other fuels appliances are the same. They rate them by input BTU's of the fuel used and you have to deduct the efficiency to get the stove/furnaces actual output.

    Last I knew, Oil was also trucked across the region in them same trucks sucking diesel fuel. NG would be about the only thing that isn't trucked around. It's pipe right to your appliance. But I am sure you get to pay some type of fee for that!

    Pellets being environmentally friendly is mostly because there carbon neutral. Trees need CO to grow and produce oxygen. The CO they release in the combustion process is equal to what they used to grow.
  16. Greg M

    Greg M New Member

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    NG at $1 per therm comes out to a cost of $10 per million BTUs input, before accounting for your furnace efficiency.
    Pellets at $187 per ton using 16,500,000 BTUs per ton comes out to $11.33 per million BTUs input.
    How did you figure that pellets at $187 a ton come out to .95 per therm? My figures show that you'd have to be at $156.75 per ton to equal .95 per therm.

    NG furnaces far exceed pellet stoves in efficiency.
    To equal the BTU output of a 90% NG furnace at $1 per therm you'd have to get pellets at $146.65 and burn them in a stove that was 80% efficient.
  17. Greg M

    Greg M New Member

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    Since this is a new house why not consider a Geothermal heat pump? A middle of the line one would be as cheap as natural gas even if you pay .18 per kw and $1 per therm. You would also save on air conditioning in the summer. Yes they cost more up front but the payback is quite good. If you're planning on living there a long time the inside unit lasts about 25 years and the outside ground loop lasts 50+ years. A geothermal heat pump also increases your resale value.

    The next house that I build for myself will have a geothermal HP.
  18. ChrisWNY

    ChrisWNY Feeling the Heat

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    You guys are getting NG at a much cheaper cost than what we're paying in WNY. I know quite a few people in my area who run pellet stoves and also have NG for heat, and the cost of heating with pellets is substantially lower than heating with NG on a monthly basis.
  19. Greg M

    Greg M New Member

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    Numbers?
  20. ChrisWNY

    ChrisWNY Feeling the Heat

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    I don't remember exact dollar amount per ccf, I do remember ridiculous tariff and other surcharges added for tax/delivery that scaled up depending on your ccf usage - I don't have NG where I live (I'm on LP), so I'm going by what I remember being charged at my previous residence (which had NG), my NG bills would approach $150-$175 per month over the winter in a relatively small (1200 sq. ft.) but well-insulated house. A coworker of mine pays $200/month 12 months per year on balanced billing for NG, his house is roughly 2000 sq. ft. and was built in 2004, which means it has modern insulation, etc. His wife is real demanding about heat so I'm guessing he heats his house up to 75°F throughout the Winter, which is why his bills are high year round, he just didn't want $450-$500 NG bills to hit him over the Winter, so he spreads the cost over balanced billing.
  21. checkthisout

    checkthisout Feeling the Heat

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    Sorry, massively careless math on my part.

    I better check my pellet piping for a leak. :)
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