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Heat pump

Discussion in 'Residential' started by pintofstout, Oct 27, 2017.

  1. jamesyarbrough

    jamesyarbrough Amateur Gynecologist

    Messages:
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    Location:
    Denison TX


    Wow! Guess that's one of them times what they write in the books at school don't work in real life.
     
    doc havoc likes this.
  2. doc havoc

    doc havoc A cunning linguist

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    Yep. When we get to that section of the text I have them cross/scribble it out and explain the reasoning. It is kind of stupid that the very textbook they are learning from is full of misinformation. We use the Refrigeration for Air Conditioning Technicians text. Modern Refrigeration says the same thing.:nono:
     
    Rather B Riding likes this.
  3. Catpower

    Catpower The Crowd Pleaser

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    Location:
    in the Cabana
    My Bro had a wood furnace for many years,it was a high priced one, but it worked real good he could put a 6 foot log in it and it would heat his house for a few days depending on the weather.It had it's own blower, and really did a hell of a good job, he had a rail system to move the logs.

    But it still was kind of a PITA but on the farm in the winter there ain't much else to do so he was saving on fuel, and it is a huge old farm house. But if you put the pencil to it he probably didn't save a whole lot, chain saws, gas labor 4 wd pickup etc
     
  4. pintofstout

    pintofstout New Member

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    Location:
    Olean, NY
    exactly what i was planning to do


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    Catpower likes this.
  5. Chuck

    Chuck SSP

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    LAX
    There's several mistakes in those textbooks
     
    doc havoc likes this.
  6. Chuck

    Chuck SSP

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    Speaking of dual fuel, a former boss sold a nice American standard heat pump on a wood furnace. :nono:
     
  7. Todd DeWulf

    Todd DeWulf New Member

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    10
    What’s the process to find the balance point?



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  8. knave

    knave Undeterred

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    Thermal balance point,

    Economical balance point,

    Or

    Comfort balance point?
     
  9. Todd DeWulf

    Todd DeWulf New Member

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    10
    I was thinking in lines of of thermal and economical but our job is comfort.


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  10. knave

    knave Undeterred

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    Comfort balance point will be around 30°, to keep the supply air above 90°.

    Thermal balance point is when the heat pump at 100% runtime will just barely meet the heat loss of the structure, and this can all be calculated or taken from manufactures literature.

    Economic balance point changes with fuel costs and electricity cost, obviously. But the best way to calculate it is to reduce it down to cost per 10,000 BTU

    There are calculators online that allow you to input cost per kilowatt hour of electric, and cost per therm of natural gas, or gallon of LP gas. Then you also have to enter the assumed efficiency of the gas heat, and the COP of the heat pump.
     
  11. knave

    knave Undeterred

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    With the newer inverter drive stuff such as Mitsubishi it will keep the air temp up even when it’s cold.
     
    jpb2 likes this.
  12. LemonWizard

    LemonWizard Blinky Lights Wizard

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    Ohighyo
    I have an all electric house so it's a heat pump for me.
     
    jpb2 likes this.
  13. Zman

    Zman Hanging by a Thread

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    The "I know a Guy" State
    Economic Balance Point should take into account cost of repairs. I'd trust a mechanical piece of equipment which has to Runs during cold weather,that is located indoors as opposed to outside,from a breakdown standpoint.
     
    knave likes this.
  14. Anita sannich

    Anita sannich Exceptionally average

    Messages:
    544
    Location:
    Spokane WA
    Whatever the outdoor temp is when you get a "heat pump blowing cold air" service call, set the heat pump to lockout 3 degrees above that. The "cold" air is just room temperature air from the blower while the equipment is switching back and forth between auxiliary and O/B trying to maintain a balance point.