Real-world calculation... ideas anyone?
Real-world calculation... ideas anyone?
(OP)
thread403-31557: Calculate Differential pressure
thread403-43928: ROOM STATIC PRESSURE CALCULATION
Hi all,
Here's a simple problem...
My friend from engineering school posed this seemingly simple situation and its been bothering me that I can't figure it out.
With a known airflow rate (cubic-m per hour, or cubic-feet per min) into a room, assuming no leakage. What would be the average pressure felt at a standard doorway (say A x B metres or feet in dimensions)?
Which formula would you use to arrive at real-world results? Any other parameters to be considered in coming up with the answer?
The desired result would be in Pa (pascals) but any input you have would be most appreciated!
:)
thread403-43928: ROOM STATIC PRESSURE CALCULATION
Hi all,
Here's a simple problem...
My friend from engineering school posed this seemingly simple situation and its been bothering me that I can't figure it out.
With a known airflow rate (cubic-m per hour, or cubic-feet per min) into a room, assuming no leakage. What would be the average pressure felt at a standard doorway (say A x B metres or feet in dimensions)?
Which formula would you use to arrive at real-world results? Any other parameters to be considered in coming up with the answer?
The desired result would be in Pa (pascals) but any input you have would be most appreciated!
:)





RE: Real-world calculation... ideas anyone?
Air yhas to get out of the room as well as into the room.....with no leakage, no air out.
RE: Real-world calculation... ideas anyone?
well... say the door is open, and the connecting room/space has airflow also pumped in, there is a pressure/force acting at this doorway from one of the sides.
how would you arrive at a result at this open door?
RE: Real-world calculation... ideas anyone?
RE: Real-world calculation... ideas anyone?
The velocity increases through the doorway adding velocity pressure. Air expands at the other side of the doorway, looses velocity pressure which is converted to static pressure.
What you're trying to find is the total pressure.
Instruments will also do the trick.
RE: Real-world calculation... ideas anyone?
ok... taking the fan curve's static pressure... which equation relating all these pressures would be THE ONE to use?
RE: Real-world calculation... ideas anyone?
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Real-world calculation... ideas anyone?
RE: Real-world calculation... ideas anyone?
can you explain a little more?
RE: Real-world calculation... ideas anyone?
Airflow through Large Openings
I haven't read it.
RE: Real-world calculation... ideas anyone?
I quickly read through that paper, it gave me a great idea on how to deal with a stratification problem that has been driving me nuts, but I do not think it will help the OP, since it mostly deals with natural ventilation.
If I understand the OP , he has a room with a known but unspecified flow rate into a room. he has another room with a different but unspecified flow and a differential pressure between the two. He then has a doorway which is essentialy a restrictor in a duct and he wants to calculate the pressure at the restrictor.
This may help, However I think Willard has it nailed :
http:/
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor