1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How is Efficiency of Heat Exchangers (HRV) determined

  1. May 26, 2014 #1
    I've be looking at the specs for Heat Recovery Ventilators (HRV).

    They commonly state that they can recover 85% of the heat. How is that possible? To me you could only every recover 50% in a perfect situation because of the equal volume of airflow's. Won't the air temperatures just stop at equilibrium?
  2. jcsd
  3. May 26, 2014 #2


    User Avatar
    Science Advisor
    Homework Helper

  4. May 26, 2014 #3
    Commercially designed heat exchangers must be designed with a fairly strict operating (especially ambient environmental) temperature window in mind to keep to high levels of efficiency. The common household so-called "heat pump" systems efficiency drops precipitously below 45 F (7.2C) for example.
  5. May 27, 2014 #4
    Thanks a lot Aleph you answered my question, that wiki was helpful.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook