Converting from OIL to gas, being pushed towards a 95% efficiency and Indirect water

Discussion in 'General Home Improvement Discussion' started by drewdin, Feb 2, 2014.

  1. Feb 2, 2014 #1

    drewdin

    drewdin

    drewdin

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    OIL is costing me an arm and a leg, they have these heat loans where there is no interest for 7 years. I am being pushed towards a 95% efficient boiler and an indirect water heater, my plumber told me that since my house is from 1927, there wis no way i could get that efficiency without going crazy and sealing the house, etc... but since the house is so old its not meant to function that way.

    He is telling me to go with an 85% to 90% efficiency and a regular water heater.

    I wanted to get everyones suggestions on efficiency and what is realistic vs what is worth the money. I am thinking that half of what the plumber is saying is true and the other half is he is old school.

    I am just starting my research and any suggestions would be greatly appreciated.
     
  2. Feb 3, 2014 #2

    nealtw

    nealtw

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    That sounds like two different dicussions. the house is the house. Your problem is, the cost of the better system compared to the cost of the fuel saved. If the house loses more heat then you will be using more fuel, I think that would point you to the system that uses less fuel. :2cents:
     
  3. Feb 3, 2014 #3

    bud16415

    bud16415

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    I agree with Neil the efficiency of your heat source is a separate thing than the efficiency of your house. Basically the heat source efficiency is a measure of the fuel burned and the heat that burning gives off and it’s the ratio between what goes into the house and whet goes up the chimney. The old systems needed to use some of the heat to get the waste products out of the house. It’s easy enough if the decision is between 90 and 95 % to take a look at what 5% of your fuel cost is and try and figure out how many years it will take to get a payback on the savings. It has been my experience that the higher efficiency units require more expensive or more frequent repairs. That may no longer true though some of the heating guys may have facts on that.

    Many times the offset in heating cost can be seen thru things like insulation new doors and windows in an old home. So strictly speaking given X amount of money to spend you could get more bang for your buck doing those things and keeping a lesser efficient heat source. I think that’s what your heating contractor might have been alluding to. Sure if money is no object you would do everything.

    An old timer once told me pertaining to small efficient cars and the cost of keeping them on the road, he said “If you wants all that economy you are going to have to pay for it!”
     
  4. Feb 3, 2014 #4

    drewdin

    drewdin

    drewdin

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    Thanks for the insight, the plumber was pushing me away from the 95% indirect options while the heat loan place was pushing me towards it. Money is an issue, if i could get more from my oil I would keep it. I guess that leads me to insulation more in the attic, the exterior walls on the second floor and the crawl spaces to try get get more for my money.

    I'll keep you posted on what i do
     
  5. Feb 3, 2014 #5

    nealtw

    nealtw

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    With out knowing the numbers or doing the math I would lean toward the more efficient system. Changing the house to high efficiency is another problem.
     
  6. Feb 3, 2014 #6

    bud16415

    bud16415

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    The thing with making improvements to the house is they keep working forever once you spend the money. It’s really two different problems with the common denominator of money. Do you keep the heat you have in the house and use it longer or do you let it go but figure out a cheaper way to get the heat. A lot of these old houses were made the way they were because energy was cheap in 1927 or whenever. Most likely they heated with coal back then and a truck would dump a load into the basement. I know several people around here that heat with wood and don’t really care how much they burn because they have an endless supply. While I know another guy that built a super insulated underground house and a couple light bulbs and the people in it keep it heated.
    My first house I looked into getting a gas well put in 30 years ago and it would have cost me $10,000 I remember thinking I could pay my gas bill with the interest off the 10k forever, or at least the payback seemed too far out to make the investment worthwhile. After about 20 years I wished I had put in the well.

    Most of the time a mixed approach is best starting with the low hanging fruit. I guess there would be a way with math to figure out where you are at now knowing the sq ft and how much energy you use based around a monthly average temp. then you could get a feel for what way to go to get the biggest bang for your buck.
     
  7. Feb 4, 2014 #7

    BridgeMan

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    I was told by a reputable HVAC guy (when shopping for a new FA unit for a house in NM) that he wouldn't go with a 95% efficient gas furnace because they consistently had high failure frequencies, and were sometimes too complex for an average service tech to efficiently work on. He also said that repair parts were not only more expensive and less reliable than the parts used in less-efficient furnaces, but that they also weren't common enough to be stocked by local wholesalers, which often meant waiting up to a week longer (sometimes in bitterly cold weather) for a needed part to come in.

    This was more than 20 years ago, so maybe things have changed regarding high-efficiency furnace reliability and their parts performance/availability.
     
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  8. Feb 4, 2014 #8

    drewdin

    drewdin

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    @BridgeMan, the exact words spoken by my plumber. I was up in the attic yesterday, there is barely any insulation and spots with none. Im going to start by getting that to an R38 and see how much oil i start saving.
     
  9. Feb 4, 2014 #9

    buffalo

    buffalo

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    My small contribution to the site , after driving Neal crazy with questions.:D

    Every unit is sized by btus per hr , which is factored by the size of your house and insulation. For easy numbers lets say your bringing in 100,000 btus of natural gas. An 80% efficient furnace will only supply you with 80,000 btus as usable heat. The rest is out the chimney. A 95% efficient will supply 95,000 btu of heat.

    I personally don't see many condensing high efficiency boilers going in around here. Boilers are much more expensive than forced air furnaces. What the price differance is between efficiency models I'm not sure , but I'd guess its sufficient. If your installer is afraid of them its probabaly because he didn't know much about them , and at that point I wouldn't want him to put it in . In my area , although plumbing outfits do install heating equipment , typically you want a heating contractor.

    I'm in the same boat right now. I have an oil boiler and poor insulation. I believe oil is approximately 4x the cost of natural gas. It's a big reason why truck fleets who drive locally are converting their trucks to run on natural gas right now. Heating oil is basically diesel fuel. The conversions are big money , but thier paid off in a matters of years.

    Back on subject , I have installed on demand boiler/domestic water units . I put one in my old house and my bill was cut in half. The boiler I replaced was pretty ruff. I will have natural gas tapped by next heating season. My plan is a forced air furnace but that would be expensive for someone hiring that out.

    Before you decide look into rebates from the utility , and write offs from the government for installing high efficiency units.
     
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  10. Feb 8, 2014 #10

    Wuzzat?

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  11. Feb 15, 2014 #11

    drewdin

    drewdin

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    @Wuzzat i downloaded the data but I'm not sure what it tells me, i just see numbers increasing on the daily. How do i correlate this to heat usage/consumption. Thanks
     
  12. Feb 15, 2014 #12

    Wuzzat?

    Wuzzat?

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    The more degree days per year, the more fuel you will use.
    With the price of oil killing you I guess you have a leaky house and/or a high fuel cost.

    A leaky house like mine may use 11 BTUs per square foot per heating degree day and a tight house may use 2. Knowing your conditioned space square footage and knowing your HDDs you can figure how tight your house is.

    With 11 BTUs and a 1000 sf house and 2000 HDDs yearly you'd be using 22,000,000 BTUs (220 Therms, 6400 kwh of elec., ~2000 kwh using a heat pump) of energy per year.
    Depending on the Heat Value/Heat of Combustion for the fuel you use and the price of that fuel per gallon/lb/cubic foot you might be able to do better.
    Your oil supplier may guarantee some minimum Heat Value for the fuel they sell you but there's no easy way to check this unless you can find a lab nearby that does this kind of testing.

    With these numbers you can make tradeoffs between how much insulation to put in so it pays for itself within a few years, and fuel cost, and maybe considering some alternate fuel (electricity? wood?).

    Depending on your sunlight
    http://www.eventhorizonsolar.com/insolation-window.html
    you may want to pipe water through a roof-top panel to help with the heating.

    For wind power, figure on a 9' diameter propeller. How's that for an eyesore? :D
     
    Last edited: Feb 15, 2014

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