Newbie furnace question

Hi...
We have a 28 year old oil furnace that has started behaving oddly (starts and stops a lot). Given the price of heating oil this year and the fact that it was behaving funny we were thinking that this might be the year to upgrade the old furnace with a new one. Our oil delivery guys sent a repairman out to check out the furnace, and he said that the old one was burning at 79% efficiency while a new furnace might burn at about 83% efficiency and cost $5000 (installed).
The neighbors across the street replaced their furnace last year and they said they've seen a significant drop in oil usage.
Is there some disconnect between what they say is the efficiency rating and actual use?
Thanks -mark
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5000.00 to replace an oil burning furnace with a new one?
Where are you lacated?
Ask your "oil guy" why. Get an itemized estimate that includes the cost of the new furnace (make & model #) and what he's charging to install it.
It sounds like your oil guy wants to make up the next 10 years of profits he's going to lose to your new oil burner's efficiency.
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First off, I doubt he measured the efficiancy of your furnace, few techs know how to do it, or have the equipment to do it. If he did, I doubt it was tht efficiant.
Second, your fuel oil supplier is the last place I would look for un-biased information about whether you should change or not! (think about it, they sell you oil!, Why would they care how efficiant your furnace is!) Find a HVAC company to look it over.
Third, $5000 is crazy, unless it is an extremely diffecult install, and/or labor rates are excessive in your area.
The last oil install I did was a difficult one, the old unit had to be cut apart be cause it was too large to fit out of the home. Then add that it was coupled to an electric air handler and AC. Thermostat wiring and fan controls, safetys were a bitch! In our area our labor rates, and the bill was $2500. Greg
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First off, I doubt he measured the efficiancy of your furnace, few techs know how to do it, or have the equipment to do it. If he did, I doubt it was tht efficiant.
Second, your fuel oil supplier is the last place I would look for un-biased information about whether you should change or not! (think about it, they sell you oil!, Why would they care how efficiant your furnace is!) Find a HVAC company to look it over.
Third, $5000 is crazy, unless it is an extremely diffecult install, and/or labor rates are excessive in your area.
The last oil install I did was a difficult one, the old unit had to be cut apart be cause it was too large to fit out of the home. Then add that it was coupled to an electric air handler and AC. Thermostat wiring and fan controls, safetys were a bitch! In our area our labor rates, and the bill was $2500. Greg
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Mark Modrall wrote:

As for buying a new furnace, figure out how much you would save at 83% efficiency compared to 79% efficiency and then figure how long you would have to wait before you start seeing any savings after spending $5000 for a new furnace.
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How did he measure efficiency . I paid 300 for a combustion gas analysis, the equipment is expensive and you get a written print out. You may be at 60% efficiency for all you know. And that test did not show true efficiency. Get bids and learn. Can you go gas, gas can get you 94.5% on many models. There are also higher efficiency oil units. Repairing would be cheaper but first you must learn what you have and what is offered. The oil Co does not benefit from you getting a new efficient unit.
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Err.. depends on what you mean by "efficiency".. One measure is how much of the fuel you actually burn, and the other is how much of the heat from the burnt fuel gets inside your house, vs. up the chimney. What you actually CARE about is: how much of the theoretical heat-content of the fuel you burn (which you can look up) ends up inside the house?
To get that, you need to know three things: How much fuel did you burn, How much air did you pump through the system, What was the average temperature difference between the air going in, and the air going out? The only "special equipment" you need is a ruler, a thermometer, and something to measure airflow.
--Goedjn
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Hi...
well, I can supply some of those answers... We live in New England (so we have some cold winters). We go through about 1500 gallons of oil a year. We have hot water heat, not forced air. During the winter we keep the house about 60 degrees, going down to about 50 at night. The furnace drives 3-zone hot water heat + the water heater.
I have the sense that it's not as efficient as it could be but don't know enough about the various metrics to sort it out myself.
Thanks -Mark

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Just to make the obvious even more so.... he means the OIL filter, not the AIR filter (although changing the air filter is a good thing to do now & again).
--Jon
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This is Turtle.
Any Furnace made 28 years ago can't be 79% AFUE for they did not know what AFUE was then. I can remember the super high AFUE furnaces in the early 1980's was a 71% AFUE. In 1976 when your furnace was made, i don't think they had a 71% AFUE but much less a 79% AFUE. I think you got a 60% to maybe a 70% AFUE furnace.
If you have a 28 year old furnace oil or gas. You would see a big difference in cost to operate them. Hey Try for a 93+% AFUE furnace and see a big difference.
TURTLE
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