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Thread: Infinity series

  1. #14
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    Its a very easy algorthym.

    Should take but 10 seconds for a person to enter the rate info into a spread sheet.
    And get the answer. For at what temp the switch over should be.

    Of course. If you want to be accurate. You now also must account for the homes load change from day time to night time.

    Plus, HPs go into defrost more often at night time then during the day time.
    Also when its snowing, or sleeting.

    This effects performance efficiency, so they need to build in a weather sensor, and photo sensor to determine solar effect.


    Or, by adding pressure and temp transducers. Along with flow sensors. They could determine the output of the heat pump at any give time. And along with the additional sensors to know the actual efficiency of the furnace when it last ran.

    Determine which one in reality would be cheapest to run.
    All this could be done as an add on to the equoipment and thermostat. So only those that want it. Would have to pay the premiumn price for the few dollars it would save.

    All those efficiency ratings you read or hear about, are lab ratings.
    Unless your house is a lab. You won't get any of those efficiencies.
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  2. #15
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    Jan 2006
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    Powell River, BC, Canada
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    The calculations to determine your economic balance points may not be difficult, but you only need to do them once. (unless your rates change daily-never heard of that) Once you have your answers, you enter them into your stat and you're done. There's not much point in adding the ability to the controller/t-stat and increasing it's cost for a one-time use. There are on-line calculators where you can easily figure your balance points such as this one: http://www.warmair.com/html/fuel_cost_comparisons.htm
    Where are you? Are you done yet? I got ONE more call for you.....

  3. #16
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    In some area. It changes from one moth to the next.
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  4. #17
    Quote Originally Posted by beenthere View Post
    Its a very easy algorthym.

    Should take but 10 seconds for a person to enter the rate info into a spread sheet.
    And get the answer. For at what temp the switch over should be.

    Of course. If you want to be accurate. You now also must account for the homes load change from day time to night time.

    Plus, HPs go into defrost more often at night time then during the day time.
    Also when its snowing, or sleeting.

    This effects performance efficiency, so they need to build in a weather sensor, and photo sensor to determine solar effect.


    Or, by adding pressure and temp transducers. Along with flow sensors. They could determine the output of the heat pump at any give time. And along with the additional sensors to know the actual efficiency of the furnace when it last ran.

    Determine which one in reality would be cheapest to run.
    All this could be done as an add on to the equoipment and thermostat. So only those that want it. Would have to pay the premiumn price for the few dollars it would save.

    All those efficiency ratings you read or hear about, are lab ratings.
    Unless your house is a lab. You won't get any of those efficiencies.

    This is very serious post and before I attempt to respond, I would like you to clarify for me couple things and assumptions.

    First of all, why are you talking about defrost cycles. I was under the impression that there is a magic temperature point where we won’t consider HP at all, therefore eliminating any kind of defrosting requirements.

    Secondly, I was under the impression that for any given equipment (yes, in a lab conditions) advantages of HP versus Gas operation can be determined beforehand and not necessarily in the real time. Again, I am assuming that under certain temperature condition HP won’t be even an option for the user. Please, understand that I am not even remotely considering electric element for heating.

  5. #18
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    Well. If your looking to shut the HP off before it needs to go into defrost.
    You don't need to worry abouot locking it out before it becomes less efficient then the furnace.
    Since you would be locking it out at 40, or 45°F outdoor temp.

    Second. There are 2 balance points for a heat pump.
    Thermal, the outdoor temp at which it can't heat your house by itself.
    But, during the day, your home needs less heat because of solar gain. And teh HP may be able to heat your home, during the day, but not at night at the sae outdoor temp.

    Economical, the point where it cost more to use it then the aux heat.

    At 40°F outside temp.

    A heat pump at a COP of 3, with a delivered electric rate of $0.13 per KWH including all taxes and transmission fees, would cost you $12.70 for 1,000,000 BTUs of delivered heat.

    A NG 95% efficient furnace in an area that has a delivered NG rate of $1.25 per therm all taxes and transmission fees included, would cost $13.16 for that same 1,000,000 BTUs of delivered heat.

    Most likely, the HP will be above a 3 COP at 40°F outdoor temp.

    What is your winter electric rate, all taxes and transmission fees.
    And your gas rate with all taxes and fees also included.
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  6. #19
    Quote Originally Posted by beenthere View Post
    ......

    At 40°F outside temp.

    A heat pump at a COP of 3, with a delivered electric rate of $0.13 per KWH including all taxes and transmission fees, would cost you $12.70 for 1,000,000 BTUs of delivered heat.

    A NG 95% efficient furnace in an area that has a delivered NG rate of $1.25 per therm all taxes and transmission fees included, would cost $13.16 for that same 1,000,000 BTUs of delivered heat.

    Most likely, the HP will be above a 3 COP at 40°F outdoor temp.

    What is your winter electric rate, all taxes and transmission fees.
    And your gas rate with all taxes and fees also included.
    Well..well..well.. I am stunned and speechless…you just killed it right there. If you are telling me that with COP of 3 and above (assuming 40+ degree day/night) it will cost me about the same considering quoted energy cost, then HP option is absolutely worthless and should not be even considered at all. Maybe it is the main reason why Carrier and other manufactures won’t provide that controller option in the first place.. LOL

  7. #20
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    Again, what are your electric and gas rates.

    I choose a low gas rate.

    Post your rates.
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  8. #21
    Quote Originally Posted by beenthere View Post
    Again, what are your electric and gas rates.

    I choose a low gas rate.

    Post your rates.
    Our gas rates are lower that is why I did not post anything. I am still shocked, how is that COP of 3 and above can't compete with COP of 0.95 under existing fuel cost. My only answer to that is to throw away all electrical A/C and HP and concentrate on designing A/C which should operate on NG, period. We have plenty of cheap NG here in North America and it should stay low if we find the way to prohibit Wall Street Crooks to play with it as they do with Oil.

  9. #22
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    So your electric rate is what i posted, or higher?

    They have gas fired A/Cs. They've had them out for years.
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  10. #23
    Quote Originally Posted by beenthere View Post
    So your electric rate is what i posted, or higher?

    They have gas fired A/Cs. They've had them out for years.
    Yeep, it is very close. I thought that they are only available for commercial use and are cost prohibitive. Do you have any idea on their price?

  11. #24
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    If I did. We still don't talk equipment price on this forum.

    They aren't cheap, but they are available..
    Your tied into just one or 2 companies that will be able to work on it.

    As far as i know, they are still available in some sizes small enough for residential.
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  12. #25
    Quote Originally Posted by beenthere View Post
    If I did. We still don't talk equipment price on this forum.

    They aren't cheap, but they are available..
    Your tied into just one or 2 companies that will be able to work on it.

    As far as i know, they are still available in some sizes small enough for residential.

    Sorry, I did not realize that it was against the rules. Anyway, could you tell me what those companies are? Do you think that I'll be able to get an honest picture from them as far as the performance vs cost comparison between electric and gas units? Are you talking about company like

    Robur Corporation
    827 East Franklin Street
    Evansville, Indiana 47711
    Last edited by energy_freak; 05-24-2009 at 04:36 PM. Reason: Additional information

  13. #26
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    Check with your gas company.

    Not sure who of them are still inbusiness.
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