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!

Efficiency, Loss...is there a more specific term?

  1. Apr 3, 2017 #1
    Suppose I heat a room directly by lighting a fire in the room, let's say it is a butane gas fire and it takes n BTU to raise the temperature by 10°C.

    Now, suppose I don't like the smell of burning gas fumes and decide instead to move the same gas fire outside and boil water to generate steam to run a generator to produce electricity to power an electric heater in the same room and it takes 3n BTU to raise the temperature by 10°C.

    Is there a technical term to descibe the 3 x BTU difference between direct heat and indirect heat in the above?
     
  2. jcsd
  3. Apr 3, 2017 #2

    anorlunda

    User Avatar
    Science Advisor
    Gold Member

    :welcome:

    The word in your title; efficiency. I'm not sure what other word you are searching for.
     
  4. Apr 3, 2017 #3

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    I think it would be best to call it something like the "relative efficiency" because the original butane fire isn't going to be 100% efficient.
     
  5. Apr 3, 2017 #4

    russ_watters

    User Avatar

    Staff: Mentor

    I don't see a problem with using "efficiency" as long as you describe clearly what you are talking about. As said, it isn't necessarily straightforward. For this situation, there is a potential difference between total and sensible energy output (lower vs higher heating value), that may still make the efficiency of the fire in the room less than 100%. And if the system is properly vented so as not to violate code/kill anyone, the ventilation should be factored into the efficiency as well.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Efficiency, Loss...is there a more specific term?
  1. Loss Coefficients (Replies: 1)

Loading...