Calculate the duty of the condensing Unit

[jakerowl1]

Hi I'm new to the forum and relatively new to the trade, I'm doing an assignment at college this is the question,

Calculate the duty of a condensing unit required to maintain the above ground beer cellar at 10 degrees c in an ambient of 27 degrees c. Take U value of the walls and ceiling 0.75 wm2 degrees c. The internal dimensions are 4m long x 3.5m x 2.5m high (ignore the concrete floor)

which formula do i need to work this out, i obviously don't want the answer as that would be cheating,

thanks Jake

[powell]

jake,

Try this link. There are manuals and programs available.

http://www.hvacrinfo.com/loadcalcs.htm

[jakerowl1]

My problem is i need the exact formula not a calculator as i have to show my working out, regards

[Brian_UK]

Although related to warmer climes than ours have a look at this PDF document which has lots of lovely calculations for you.

Do a few to show that you know what you're doing then use software to speed the process.

http://www.pdhonline.org/courses/m196/m196content.pdf

edit: Sorry, lead in page to the above link..

http://www.pdhonline.org/courses/m196/m196.htm

[JOCK992]

Hi Jake
As you are still at college I was wondering if you, or anyone else out there would be able to help me at all with my engineering coursework??? Its about the role of an engineer. I have been through 3 refrigeration engineers who all seem to be letting me down so my work is unfinished - h e l p!!!

[yunus4u]

what is double expansion could some one can explain me, how it will define,

[Brian_UK]

what is double expansion could some one can explain me, how it will define,

It is used with steam engines where the high pressure steam having been used in the high pressure cylinder is then used in the low pressure cylinder, hence it is expanded twice.

Please raise your question in a new thread in future, do not tag it onto someone else's thread.