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Cycles/ Hour ?

Most of the HW digital T-Stats from the 8775 to the 8000's are using a cycle rate set by the installer i.e. 1 C/H for steam or Gravity Hot Water, 3 for Pumped Hot Water and so on. My question is; can anyone tell me the concept, theory or the math behind it. Knowing how it is doing what it does, would help in the diagnosing and fine-tuning of those occasional systems that do not behave characteristically for various reasons. I mean is it just tightening the overshoot like the old anticipator or is it more sophisticated then that.
Thanks

Comments

  • carol_3
    carol_3 Member Posts: 397


    The cycle rate has to do with how quickly heat is emitted. For the old cast iron radiators, it takes a lot of time, so the cycle needs to be longer. That means there are fewer cycles per hour. 1 for steam, 3 for hot water. Honeywell generalizes all hydronics together, but we know what heat transfers faster from fin tube than from cast iron radiators. I think 6 cph is usually better for fin tube. For forced air, tradiaitional furances are at 6 cph, but high efficiency are preferably at 5 because the heated air temp is lower, and it takes more time to deliver the heat. Air conditioning just pretty much has a standard of 3 cph.
    In-floor radiant depends upon the floor material and water temp. Still, the longer it takes to emit the heat, the fewer cph.

    Higher cph usually gives tighter temperature control because there are more opportunties per hour to correct the temp. For example, if there is solar heat gain, that's a reason to start with more cph so that the system has a chance to notice that the sun has begun to add heat sooner rather than later.
  • Barbarossa
    Barbarossa Member Posts: 89
    thanks

    It was helpfull info, and in this case due to the hi thermal inertia of the building plus pump H/W with Cast iron I will try less c/h. thank you
  • KCA_2
    KCA_2 Member Posts: 308
    Hey Carol..


    I hear that your in Antartica?

    What do you use as your WWSD point?

    LOL....

    :-) Ken Ament
    Used to be Ambery Mechanical Co. in Colorado Springs..

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    :-) Ken
  • carol_3
    carol_3 Member Posts: 397


    I AM in Antarctica. I'm a heating mechanic. Isn't that a hoot! I know I'm going to be sorry I asked, but what's a WWSD point?
  • KCA_2
    KCA_2 Member Posts: 308
    Warm Weather shut down..



    Hahahhaaa.. If there is one.. I posted a question on the Wall about overseas employment and Dan told me that you were in the south.. Any openings? :)

    I spent a lot of time in Greenland back in 1980.. what a place.. I imagine that Antartica is just as beautiful in a pristine kinda way.. I remember flying over the water going to Thule.. Couldn't tell where the water was or where the land was.. everything was white.. The sky too!! LOL...

    :-) Ken


    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    :-) Ken
  • KCA_2
    KCA_2 Member Posts: 308
    I applied


    to Raytheon and they wrote back asking me some questions..
    Hmmm.. Whats it like down there?

    You can write me at amberymech@aol.com if you would rather.

    :-) KC

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    :-) Ken
This discussion has been closed.