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Carrier HybridHeat : how is the switch from heat pump to furnace done?

6 years ago

Hi, all. I'm looking at getting a Carrier HybridHeat system installed and wanted to understand how the switch from heat pump to furnace done? Do I set a particular outdoor temperature at which I want the system to start using the furnace instead of the heat pump?


Thanks in advance,

Nick


Comments (14)

  • 6 years ago

    Basically, yes. Your installer should go through this in detail with you when they have completed the installation.

  • 6 years ago

    Is it something that I can then alter or override temporarily myself? Does it matter what thermostat I use?


    Thanks,

    Nick

  • 6 years ago
    last modified: 6 years ago

    Yes, with the correct thermostat, heat pump can be shut off and homeowner can use gas heat exclusively. I would hope you have performed a comparison of operating costs between electric heat pump versus nat gas or propane so you fully understand the leverage if any between the fuel sources. I put in dual fuel/hybrid system over 10 yrs ago. Electric rates are regulated where I live while nat gas rates are more market driven. While nat gas prices have dropped substantially, electric rates continue to march higher. I have not used my heat pump for heating at all in about 3-4 yrs.

    IMO

  • 6 years ago

    Thanks for the comment. I also plan to pair this with solar panels (and batteries eventually) which I think would make the heat pump a better proposition.

  • 6 years ago

    for above poster...do you have nat gas service to your home?...

    IMO


  • 6 years ago

    Yes, both gas and electricity.

  • 6 years ago

    what is your electric rate cost/kWH and cost of nat gas price/therm? I don't understand the idea of offsetting electric use with solar panels if nat gas is cheaper operating cost than heat pump use. I hope you will analyze this very carefully.

    IMO

  • 6 years ago

    I looked at my past bills and it seems to be about $.21/kWh and $1.5/therm.

  • 6 years ago

    What is your location?....you should recheck these numbers especially nat gas.

    IMO

  • 6 years ago

    When comparing fuel prices, you should subtract any monthly service charges.

  • PRO
    6 years ago
    last modified: 6 years ago

    with .21 cent KWH electric rate, solar panels are probably not a bad idea, if you have the real estate necessary and a clear view to the southern sky. But battery system you may want to think about a little longer.... because batteries require maintenance if you don't do the maintenance the batteries will be eaten like candy., which will drive up costs making the solar system pointless.

    Typically batteries are used if grid power is unreliable, otherwise you would have what is called grid tied solar array. When the sun is out it automatically switches you to solar, if the sun is not out then you use grid power.

    If you size the array right there will be times you throw power back on the grid thus reducing your monthly electric bill to hopefully $0 or close to it.

  • 6 years ago

    I'm thinking of something like a Tesla Power Wall which they claim is maintenance free.

  • 6 years ago

    The winter design temperature in San Jose is 38 degrees. That is mild compared to most parts of the country. You also like to keep the thermostat to a low temperature in the winter. I don't think you need to spend thousands of dollars in trying to keep your heating costs low.

    Solar panels and a Tesla Power Wall are very nice, but unfortunately very expensive. You should do a return on investment analysis to see if you are ever going to get your money back through the savings.

  • PRO
    6 years ago
    last modified: 6 years ago

    Tesla Powerwall is a bit different as it uses batteries made with Lithium, however the base model will at best give you only a few hours of run time. Costs $5,500 of which doesn't include installation costs, taxes, fees, permits etc.


    Tesla Powerwall

    For that 'maintenance free' solution you will most likely be forced to replace the powerwall every 10 years, maybe less than that as if your system loses capacity leaving you in the dark your choices will be few.

    So to do some rough math to be possibly free of the electric grid... let's say you can depend on 12 hours of full sun everyday. (of which we know is not possible)

    So you would need a battery system to deliver the other 12 hours of power. Lets say the base pack works for 2 hours. So you would need 6 times this amount.

    5500 X 6 = $33,000! This doesn't include installation, fees no solar panels etc. to make matters worse you spend this every 10 years or less. ( nothing is free --- if you don't spend it on maintenance you spend it in dollars.)

    For comparison: Your power usage at 1500 kwh's per month at $0.21 per KWH is $315 x 12 = 3780.00 x 10 years is 37800.00 from the grid cost. Just realize solar array prices were not included in above powerwall costs. I believe by the time you figure installation costs for the powerwall, it would be cheaper to just remain on the grid. This is why battery backup is only used for power critical uses. The cost doesn't justify the means.