Ducting design and analysis? Need help. 1

[jasno999]

In the near future I will be tasked with analyzing a heating and air conditioning system. Part of that analysis is goign to include looking at the distribution system that is in existanance and tryign to determine the flow losses and thermal losses thru each of the branches of ductwork.

I have a general idea of how to do this and have purchased some books as well as read thru some of the ASHRAE documentation. I understand basic concepts but I am still not ceartain about how to bring it all together.

I am hoping that somebody can help or point me torwards a book that is mroe comprehensive and eaiser to understand than the ASHRAE document. I know that bends and take-offs have ceartain loss coeeficients associated with them and you can use charts to find those values but I am still a little fuzzy on the details.

Also in termos of the heat losses I don't know where to begin on doign that type of analysis. For example if you run air down a duct that is not insulated how d oyou figure out the thermal loss, and how do you do it with ductwork that bends or has takeoffs? (Is there an affect from branches and direction changes to the heat loss?)

 

[STYMIEDPIPER]

jasno999
Did you locate the SMACNA "HVAC DUCT SYSTEM DESIGN" book that I had suggested to you per your posting at the end of October?? I do not know if it is still available. It is very informative for the beginner.
Depending on your time frame--Community College in my neck of the woods offers HVAC courses that walk you thru the fundamentals and are relatively inexpensive. A semester in the evenings actually makes time fly fast. The Electric company in my area use to offer HVAC courses. Check with your local utility.
If at all possible, convey to your company that you are willing to tackle the situation but are slightly at a disadvantage in the area of HVAC. Hire a contract consultant to review the situation, make suggests to resolve the situation, and point you in the right direction. It is a win/win for you and your company. The situation gets resovled and you obtain valuable information for the next project.
Have you or your company established a good working relationship with a HVAC sales rep in your area. They probably would be more than willing to offer you advise.

 

[jasno999]

I saw the SMACNA book but it is $177 which is ok if it is goign to give me what I need. But I have heard form others that the SMACNA book is more of a usful information type book and not a how to book.

I need both really. I need a book that will give me the basics and allow me to analyze ducting systems and build ducting systems.

Basially I need to take ductwork and figure out what the flow losses are goign to be as well as what the thermal losses are goign to be. I understand the concept but need somethign to walk me thru what equations to use and how to use them..

No time for a class I need to learn this on my own and fast.

 

[BigInch]

Don't you really want to connect with the HVAC guys?
HVAC Threads are here,

http://www.eng-tips.com/threadminder.cfm?pid=403

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[JohnBreen]

http://www.pipingnews.com/airduct.htm

http://www.hvactools.net/products/1481.shtml

http://www.ais-engineering-books.com/ProductCart/pc/viewPrd.asp?idproduct=168

http://www.llnl.gov/es_and_h/hsm/doc_12.02/doc12-02.html

http://www.connel.net/freeware/airduct.shtml

Principles of Heating, Ventilating, and Air Conditioning, by H.J. Sauer, Jr., R.H. Howell, and W.J. Coad.

ASCE has a good handbook for structural design of ductwork

http://www.asce.org/bookstore/book.cfm?book=3644