2 replies to this topic

[DaleBrewster]

Hello,

 

I was reading the article ''making decisions with insulation'' and I am posting my question here because it will not allow me submit comments in the comment section.

 

I was wondering, on page 4 for the internal heat transfer coefficient equation, the bottom line is multiplied by 3.6 even though in the equation it is not stated. Also, in the available spreadsheet the overall heat transfer coefficient is also multiplied by 3.6?

 

I am asking because I am a recent Mechanical Engineering graduate on a placement in a company and have been asked to design a spreadsheet that can predict the temperature drop across a pipe for various length, insulations etc.

 

If someone could explain to me why the 3.6 is there, as I have so far excluded it from my calculations and have used the method from that article, but my results vary in comparison.

 

Thank you

[Art Montemayor]

Dale:

 

As an engineer, you have to identify your sources as to title, author, & location when you cite a technical article.  As engineers, we are expected to be concise, accurate, and thoroughly detailed in our calculations and references.  Our members are probably capable and willing to help and assist you - but you have to tell them where, exactly, the article you cite is located.  Otherwise, they don’t know what you are referring to.

 

Without your precise and accurate information as to where to find and read the article, our members are obviously helpless in trying to help you.  We await your referenced information.

[Pilesar]

I suspect the article is this one: http://www.cheresour...with-insulation

I don't find the equation you are asking about, but perhaps the '3.6' refers to conversion between watt-hours and joules.