Insert Temp With IR

blackdog1 Posted By blackdog1, Jan 19, 2013 at 6:56 PM

  1. blackdog1

    New Member

    Jan 4, 2012
    Ok, I am all confused with measuring stove temps on an insert...what is best way to get accurate temp using an IR on a flush insert?

    Background...first year burning new insert (Regency Alterra CI1250), mostly burning bio bricks as I was too late in ordering seasoned wood. Burning evenings and weekends when we are around. It seems I can only have 2 bricks in and temp is easily up to 700 degrees if measured by shooting through the glass at various points inside the stove. I can't imagine what temp would read if I loaded the stove up? I keep reading the stove top temp should be cruising around 400 to 500 but not being able to measure the stove top I am not sure what best spot is to measure?

    2nd question I guess would be, can I really load this stove up and get a several hour burn and I say several hours because right now I am only putting in 2 or 3 bricks at a time and need to reload basically every hour.

  2. Woodreb


    Nov 15, 2012
    NW CT
    I'd try the middle of the door just below where the hot air exits when the blower is on, or maybe on the surround just about where the hot air exits. Measure on the door frame not through the glass.

    We mix Envi-Blocks in with our wood. I use 2-4 depending on what the outside temps are like and then load the box up with wood. I've tried the bricks by themselves and I think I've loaded a pack of 6 and had them last overnight (~10pm - 6 am).
  3. Woody Stover

    Woody Stover
    Minister of Fire

    Dec 25, 2010
    Southern IN
    On the Buck 91, I have the thermo on the front face, about where the top plate of the fire box connects. You could open the door and shoot the inside of the stove and see how close that is to your surface-mounted thermo.
  4. HotCoals

    Minister of Fire

    Oct 27, 2010
    When you shoot the glass you're not getting the inside temp..just the glass.
    You can figure the inside is about double the temp.

    You shutting the air almost all the way down?
  5. jdp1152

    Minister of Fire

    Oct 4, 2012
    Don't bother trying to get the temp from the front. The temp in the stove is not going to be the same temp on the top. It's a jacketed box with a fan, by nature, the stove top will be somewhat cool if you've got the blower on.

    My tips from someone in year two with one:
    - Put the blower on Auto. Leave your air wide open until that kicks on. Start throttling down by 50% at that point. Let the flames build back up, bump it down a quarter more. Rinse repeat until you've got the desired fire you want. I throw the blower on a bit sooner now that I have a feel for it, but that's a good starting point.
    - I've burned mostly kiln dried with some low to mid 20s Ash mixed in. I had the flue swept by a professional after year one and almost zero creosote. Guy said it was the easiest clean he's had in several years. Mostly just ash from the last few loads.
    - You will not get anywhere near the marketing burn times. I get 2-4hrs with a full load....5 if I'm lucky. Still infinitely better than an open fireplace.
    - It's a small stove. It's not going to heat your home. It will keep 1000 sq ft of my home warm (68-71 degrees) with the blower on high. I have an awkward layout where mine is, so your mileage may vary. I say with blower on high...I usually crank it down once I get the space warm and bump back to high as it starts hitting the coaling stage.
    - You'll read about raking coals forward....experiment. Doesn't work well with mine. I get unburned coals in the back...big chunks. I pull some forward, but leave a layer of hot ones in the back. Sometimes I pull the black ones forward and replace with hot ones.

    If I think of more when the spirits aren't flowing, I'll follow back up. It's not a bad insert, but you're not going to get the ease that many on here talk about with theirs.
  6. Jon1270

    Minister of Fire

    Aug 25, 2012
    Pittsburgh, PA
    Assuming you want to know the temp so you can apply the advice and experiences you read about elsewhere on this forum, keep in mind that most temps being referred to are stovetop or flue temps, not the door or glass or firebrick or secondary air tubes. It's not easy to measure flue temps on an insert, but stovetop temps are doable. My Osburn insert is similar to your Regency, and I have been pointing the IR through the vent at the top, angled slightly down so the laser dot hits the top of the firebox a few inches inside. I can do this across most of the width of the stove, but I go by the temp in the middle because that's where it's hottest. You want to check it where it's hottest, because part of what you're doing is avoiding temps that could damage the stove.

    Longer term, I'll probably install a thermocouple and a PID because having to reach for the IR gun all the time gets old.

    Here's how I'd think about the burn times: I haven't tried any of the manufactured fuel products like Bio Bricks, but I suspect you might be able to get longer burns from full loads of dense hardwood splits. Generally, more fuel doesn't necessarily mean hotter. A simile I've seen several times here is that a full stove is like a full automotive gas tank; it lets you go further, not faster. But then, your stove's air control is not quite like a throttle. You can adjust the size of the opening through which air is admitted, but you can't close it completely, and at any given shutter position the amount of air going in varies with the temperature of the stove, because higher stove temps increase the draft, which in turn pulls air in at a faster rate, which can further increase the temperature and pull in even more air. The combustion rate is also limited by the surface area and moisture content of the fuel. Bio Bricks don't have an inordinate amount of surface area, but if they have very low MC, it may very well be possible to overheat the stove by using too many at once. What do they say in the directions?
  7. blackdog1

    New Member

    Jan 4, 2012
    Appreciate the replies...yes, I am trying to understand temp to apply others experiences with running their stoves. I will try some of the suggestions.
  8. bryan


    Aug 10, 2012
    Wilmington, DE
    I'll ditto everything Jon said. I have a Century insert and aim an IR gun through the vent opening on top trying to stay consistent as to where I am it. I also keep a magnetic thermometer in the upper corner, but during heat up its typically 100 °F behind the "stovetop".

    I've been heating with pallets mostly this year, my first, but with weather finally getting truly cold I've switch to using some of the cord wood I know is seasoned. Goodness what a difference. I can get heat with pallets (400-450 °F using a couple pieces of the thick parts) for 45 minutes between reloads, but you can see they aren't burning efficiently as secondaries are going like gas burners and then like a switch the wood is spent and just coals. For me in that situation turning the air down doesn't seem to slow the off gassing, it just creates more unburnt gasses. If I put in more pallet wood I can get more heat, but then I have an even worse situation of too much off gassing and not enough air to burn it.

    As Jon said I'm thinking thermocouple as I obsess over the temperature but having to walk across the room time and again gets old. That way I can play Black Ops 2 and know the temp of the stove at the same time.
  9. danham


    Jan 12, 2012
    Cape Cod, MA
    Digital IRs give the appearance of accuracy but are subject to lots of variables, so their best use is to track changes, not absolute temps. Inserts are tough because the available measuring spots are limited. However, you can employ an IR to control your stove if you use your gun properly. Use your eyes on the fire to get the stove running at a "normal" temp. Pick a spot and shoot through the glass and note the temp. Run the stove hotter or cooler and note the difference, always shooting in the exact same spot. Now pick a spot on the front near the door to get a surface temp benchmark. Go through the same hotter/cooler exercise.

    Regardless of what the IR reads as an absolute temp (which is nearly useless anyway, due to all the variables between stoves and setups), you will know over time if it is running hot or cold relative to its sweet spot. The fact that shooting the glass is "inaccurate" is not a problem as long as you note a benchmark and are careful about shooting the same spot each time to detect changes.

    For example, my gun says my insert runs best at around 650-700 in the firebox. But I would never claim that this means it is actually 650 in there or that you should aim for 650 on yours. But it does allow me to see that wet wood drags things down to around 400 and an occasional extra-dry flaky split will raise temps to 750 or so. I can then adjust accordingly.

    In other words, your eyes work pretty well for monitoring the burn, and once you calibrate your gun to your stove you can quantify what your eyes are telling you.


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