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Thread: Black Bulb

  1. #1
    Automated Home Legend chris_j_hunter's Avatar
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    Default Black Bulb

    Black Bulb can be the best way to sense temperature for best comfort, so thought these might be useful :

    https://www.globalltd.co.uk/Energy_M...ors__1589.html

    http://www.t-mac.co.uk/SensorDetails.aspx?p=114

    second of which includes a version with 0-10V output = double what a QAI can take, of course !

  2. #2
    Automated Home Legend Paul_B's Avatar
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    I don't think that is true for the QAI, I seem to remeber talking with Karam about 3.3V is native, 5V is default and 10V is possibly with a calibaration before the unit is sent out

  3. #3
    Automated Home Legend Paul_B's Avatar
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    Additionally I wonder if this would make a better control system for my newly installed radiant wall panels from Variotherm (supplied by Construction Resources)

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    Automated Home Legend chris_j_hunter's Avatar
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    >10V is possible ...

    ah, good ...

    >better control system ...

    yes, I would say, even regardless of means of heating, because radiant environment is a key thing for individual comfort ...

    eg: see 4th para in :

    http://uk.groups.yahoo.com/group/UK_.../message/71232

    air quality being the other ...

    still, the devil will be in the detail, as always !
    Last edited by chris_j_hunter; 12th March 2009 at 09:03 PM.

  5. #5
    Automated Home Legend chris_j_hunter's Avatar
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    found another sensor - seemingly better-priced, and maybe neater, too :

    http://www.axio.co.uk/shopdisplaypro...rature+Sensors

    AX-TE-RBN-T ... 10K3A1 - 13.00 ...
    AX-TE-RBN-A ... 10K4A1 - 13.00 ...
    AX-TE-RBN-H ... 20K6A1 - 13.00 ...

    datasheet here :

    http://www.axio.co.uk/data%20sheets/.../ax-te-rbn.pdf

  6. #6
    Automated Home Legend Karam's Avatar
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    Interesting. I've known this concept used for external application where the sun beating down on you can make a big difference to perceived temperature level inspite of 'temperature in the shade', but I wonder how much qualitative value you get inside a home. Anyone seen any such research documents? Obviously another important factor is relative humidity and - I personally find - even small airflow (draughts :-) ).

    Yes the QAI can be supplied to range 0-10V, though I note that the list above shows a number of NTC thermistor options which can I suppose be connected in as part of a potential divider with suitable linearising mapping being done in Cortex but resolution will be relatively low as compared to something like a DTS or THS.

  7. #7
    Automated Home Legend chris_j_hunter's Avatar
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    am convinced radiant temperature is a key factor, as much as air quality (temperature, humidity, velocity, flow pattern, odours, dust, etc) ... warm air & cold walls miserable, warm walls & fresh air much better ... etc, etc ... for evidence see, eg:

    http://en.wikipedia.org/wiki/Thermal_comfort

    http://en.wikipedia.org/wiki/Mean_radiant_temperature

    http://en.wikipedia.org/wiki/Operative_temperature

    http://en.wikipedia.org/wiki/Room_air_distribution

    http://en.wikipedia.org/wiki/Indoor_air_quality

    and references therein !!

    we're certainly trying to pay attention to all the factors (new build, so half a chance) and will be including black bulb, and the rest, 'though need to decide which sensor option - & be sure of sufficient resolution !
    Last edited by chris_j_hunter; 16th March 2009 at 12:07 AM.

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