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If you program furnace thermostat to a certain degree, will it usually vary one

  1. brakel2 profile image79
    brakel2posted 6 years ago

    If you program furnace thermostat to a certain degree, will it usually vary one or two deg up & down

  2. stugod profile image76
    stugodposted 6 years ago

    It will vary a fair bit due to latent heat convection and not least of all where it is positioned

  3. mkeith profile image62
    mkeithposted 6 years ago

    The thermostats are usually programmed to only cycle with a certain difference of where it is set.  If it is for heat, the the optimal degree is what you set it at.  As long as it is within 2 (i think is what mine is programmed for) or 3 degrees, the blower will stay off, but if it goes lower, then it kicks on.  Conversly for cooling, it will range high 2 or 3 degrees before kicking on the air conditioner.

  4. Manna in the wild profile image70
    Manna in the wildposted 6 years ago

    Yes it does this. The thermostat is part of a control-loop with feedback. The phenomenon you notice has a name. It's called 'hysteresis' and you can read all about it here-> http://en.wikipedia.org/wiki/Hysteresis.

    For a thermostat, the hysteresis is designed-in -- to avoid uncontrolled rapid switching that could happen if the system switched on and off at exactly the same temperature.

    (It's not due to latent heat convection stugod unless you mean something similar but I don't recognise the terms you used.)

 
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