HVAC formula question
Results 1 to 7 of 7
  1. #1
    Join Date
    Sep 2005
    Posts
    1
    I'm currently enrolled in an HVAC apprentice program and as a bonus assignment, the instructor gave us a formula and asked us to find its meaning and application.
    Try as I might though, I couldn't find anything in my books or on the internet on this formula.
    Does anyone here have even a general idea what this formula is and what it's used for?

    Q =
    q
    --------------------
    (Tr-To)(60P Cp)


    Q = Ventilation Rate - CFM
    q = Room Heat - Btu/hr
    Tr = Allowed Room Temp - Farenheit
    To = Outside Air Temp
    P = Air Density - Lb M/Feet cubed
    Cp = Specific Heat of Air = 0.24 Btu/lb M Farenheit

  2. #2
    Join Date
    May 2004
    Location
    Illinois
    Posts
    2,843
    That's the formula you'd use to find how much ventiliation [exhaust] you need in something like a generator room. The air quantity is based on how hot you can let the room get.
    "If I had my life to live over again, I'd be a KA." - Albert Einstein

    It's later than you think.

  3. #3
    Join Date
    Apr 2004
    Location
    where you at?
    Posts
    3,359
    try the ASHRAE handbook(s)...it's ALL in there.


  4. #4
    Join Date
    Sep 2004
    Posts
    3,157
    ralphtheplumber

    Buy a guy a fish and you feed him for a day

    teach him how to fish and you feed him forever


    what I am asking you is this : Make us work for the answer a bit. If all we have to do is post a class assigned question and get an answer , just like that , we are going to need you to take our tests for us also

  5. #5
    Join Date
    May 2001
    Location
    Bennington, Vermont U.S.A.
    Posts
    13,864
    Sell a man a fish and you feed him for a day.

    Teach a man to fish and you ruin your market share.


    (you'll also learn that latter on in life.)

  6. #6
    Join Date
    May 2004
    Location
    Illinois
    Posts
    2,843
    Originally posted by ct2
    what I am asking you is this : Make us work for the answer a bit. If all we have to do is post a class assigned question and get an answer , just like that , we are going to need you to take our tests for us also
    You must have missed the part where he said:

    Originally posted by jgman
    Try as I might though, I couldn't find anything in my books or on the internet on this formula.
    Please note that he's not asking for diy advice, or anything else that's likely to get him into trouble. Now that he knows what the formula is for, he can go figure out what it means and finish his assignment.
    "If I had my life to live over again, I'd be a KA." - Albert Einstein

    It's later than you think.

  7. #7
    Join Date
    Sep 2004
    Posts
    3,157
    No i didnt miss that part , and I appricate the answer that you gave him ...as a matter of fact I got my book out after reading your answer to look it up myself


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event