GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

quantitative relationship between COP and Δt

GBA Editor | Posted in Energy Efficiency and Durability on

I’ve come to realize the COP drops as Δt increases, but what’s the quantitative relationship between them? For example, now I know the COP at a given temperature difference, how do I calculate the COP at other temperature differences? Thanks.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. jklingel | | #1

    So that I can follow this thread, what is COP?

  2. Anonymous | | #2

    to John Klingel
    COP, coefficient of performance, a term used in evaluating energy efficiency.

  3. Riversong | | #3

    The relationship will vary depending on the size, type and efficiency of each heat pump. See:

    What you really should be looking at is the SEER (seasonal energy efficiency ratio) or HSPF (heating season performance factor), which takes into account the seasonal variations in source temperature and the part load factor, which are climate zone dependent.

  4. Riversong | | #4

    Or, perhaps, this is what you're looking for:

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |