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Measuring heat

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by ootski, Feb 18, 2008.

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  1. ootski

    ootski New Member

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    Fredonia NY
    Other than hanging a meat thermometer in front of the unit, is there any definitive way of measuring heat output???? I would like to know if the new pellets I am using are better than the old ones tks

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  2. webbie

    webbie Seasoned Moderator Staff Member

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    No real way of doing this with any degree of accuracy - even with a thermometer. You would need at minimum to run a number of tests on the fuel and have lots of combustion testing instrumentation.
  3. staplebox

    staplebox Member

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    I DO use a meat thermometer!

    I am no scientist but here is what I do:

    I have a kitchen meat thermometer (digital, with about a 2ft cord) set about 3ft in front of the stove. The probe hangs in the air close to where the unit can blow right on it. I leave it in the same place.
    I have a stove thermometer on the front of the stove I also leave in the same place.
    I have an indoor/outdoor thermometer and leave both sides in the same place.
    I also look at the digital thermostat that is used for the oil heat, located in another part of the house.

    Using all of those, I change pellets or stove settings (not both at the same time) and keep track of the differences. The only variable I can't control is the outside air temperature.

    For instance, if I run the stove on a 1-7 setting with an outside temp of 35deg and the Fireside pellets I have now, I get temp at 3ft of 82-84deg.
    Same outside temp and same stove settings with Clean Energy pellets and I get 87-89 degrees at the same 3ft distance. Stove surface temp will also be about 50deg hotter. The other thermometers help me keep track of changes over time.
    To me, it seems fairly clear that one burns hotter than the other. It's enough to guide my pellet buying decisions.
  4. cntbill

    cntbill New Member

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    I picked up a magnetic thermostat, which is really for use to monitor a wood stove. I have it placed on the upper corner of the stove where I believe is about the hottest area (you can just barely see it in my avatar). I have not moved it since I placed it there, and what I have done for my testing is to clean the stove, then burn for a few hours on a low setting of 1, then burn a few hours a little higher at 4, so I use the same settings and record my temps. I have found a variance of 20 -50deg, with most I check with the exception of one brand that was at least a 100* cooler. Although I do agree it is no where near 100% accurate, but I figure it is close enough for me to decide which brands, burn the best for my stove. The ones that vary 20* or so I don't get excited about but 100*, well there is something wrong there IMHO.
  5. galen

    galen New Member

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    NW Missouri
    I do the same as Bill. But I also have a infrared digital thermometer. Use it at work, but bring it home sometimes to check the temperatures.
  6. ootski

    ootski New Member

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    Thanks for the ideas Will try the meat thermometer first to try to set a baseline then go from there I have accesss to a thermal device from the Fire Hall and will try that also. There is a lot to this that I did not plan on. Have just left the factory default settings alone so far but I think its time to tinker so if I don't burn the house down , will let you know the results
  7. davevassar

    davevassar Member

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    Keep in mind that measuring the heat output and comparing it has to be precise. For example,
    If you power your stove down to clean it, it takes a while to get up to temperature. Measuring output at different times will give you different results.

    When comparing pellet heat output, be sure to test with similar environments. When I measure, I clean the stove, and fire it up and let it run for 24 hours. Take a reading, and note the time and how long the stove has been running.

    Then, to measure them against another pellet brand, Clean it, fire it up and let it run for 24 hours. Then you have a true comparison.
  8. webbie

    webbie Seasoned Moderator Staff Member

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    What I am getting at is that these type of measurements can be shewed off by so many factors - that they end up being mostly entertainment. Just some of the factors that would affect it:
    1. Exact voltage being delivered (yes, blower speed varies).
    2. Temperature of the outside air being introduced.
    3. Temperature of the inside air at the place where it enters the convection blower
    4. Density of the pellets
    5. Moisture content of the pellets
    (note that these last two can vary even within a bag or a ton).
    6. exact seating of the pellet pot, ashpan, etc.

    and probably many more factors.

    So I would argue that it almost never is a true comparison. Still, it sounds like fun.
  9. MainePellethead

    MainePellethead Minister of Fire

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    I really think people just are looking to get an "approx.".....I dont think their realistically trying to get an "exact" reading. I know when I check my output I'm looking for in the "ballpark" range to see if the heat output fluctuates greatly from pellet brands at all.
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