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  1. #1
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    Why is EER greater than 1?

    Dear colleagues, could anybody please explain the reason why Cooling Energy is greater than electric energy delivered?.

    Here we use Refrigeration Watts (more than BTUs), so lets say a EER of 3 means that I can get 6kw (refrigeration) delivering only 2kw (electric).

    Knowing that we cannot create energy, how do we explain this?

    I know this may sound basic for some, but Id like to clarify concepts.

    Thank you!

  2. #2
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    I think you're referring to Coefficient of Performance (COP) rather than Energy efficiency ratio (EER).

  3. #3
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    Quote Originally Posted by jtrammel View Post
    I think you're referring to Coefficient of Performance (COP) rather than Energy efficiency ratio (EER).
    Example : electric heat gives a dollars worth of heat for a dollars worth of electricity if talking COP & a heat pump with COP of 3 gives 3 dollars of heat for each dollar spent.
    EER = BTU's/Watts

  4. #4
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    Quote Originally Posted by jtrammel View Post
    I think you're referring to Coefficient of Performance (COP) rather than Energy efficiency ratio (EER).
    COP is used when referring to Heating and EER is kind of an equivalent for Cooling. Im asking about EER in cooling systems.

  5. #5
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    Quote Originally Posted by oldguy1949 View Post
    Example : electric heat gives a dollars worth of heat for a dollars worth of electricity if talking COP & a heat pump with COP of 3 gives 3 dollars of heat for each dollar spent.
    EER = BTU's/Watts
    Yes, but it's more correct talk about Energy or Power.

    And also, EER is not always calculated on BTU basis, it's also Watts (refrig.) / Watts (Electric.)

    You can check it here if you read some spanish: http://revistadigital.inesem.es/ener...icas-tecnicas/

  6. #6
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    Quote Originally Posted by Martin100181 View Post
    Dear colleagues, could anybody please explain the reason why Cooling Energy is greater than electric energy delivered?.

    Here we use Refrigeration Watts (more than BTUs), so lets say a EER of 3 means that I can get 6kw (refrigeration) delivering only 2kw (electric).

    Knowing that we cannot create energy, how do we explain this?

    I know this may sound basic for some, but Id like to clarify concepts.

    Thank you!
    I'm not sure I understand your question? 1 watt equals 3.412 btus so in your example 6kw=~20,000btus. With 2kw of power you get an EER of ~10 (20,000btu/2kw). All The components and the refrigeration cycle is what makes it more efficient. The lower the compression ratio the more efficient it gets because the compressor doesn't have to work as hard. That's why a larger condenser and larger evaporator increases EER. It lowers the condensing temperature and raises the evaporator temperature.

  7. #7
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    Quote Originally Posted by Martin100181 View Post
    Dear colleagues, could anybody please explain the reason why Cooling Energy is greater than electric energy delivered?.

    Here we use Refrigeration Watts (more than BTUs), so lets say a EER of 3 means that I can get 6kw (refrigeration) delivering only 2kw (electric).

    Knowing that we cannot create energy, how do we explain this?

    I know this may sound basic for some, but Id like to clarify concepts.

    Thank you!
    If you convert electricity to heat directly with heat strips, you are getting a COP of 1 or, 100% efficiency.
    However with refrigeration you are not converting electricity to heat. You are converting electricity to a mechanical process in order to move heat that already exists, which if done correctly is a more efficient use of power.
    "If you've eliminated all other possibilities whatever remains must be the truth."

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