[TRNSYS-users] Coil ByPass Fraction

[Fred Betz]

The way to correlate bypass fraction with the manufacturer's data sheet is through the approach temperature.

You adjust the bypass fraction so that the approach temperatures match the selection of the coil.

It's somewhat iterative so I've created a separate small model with a constant air flow and water flow that I input and then adjust the bypass fraction until the approach temperature is about right for my actual selection.

Fred


Fred Betz  PhD., LEED AP
Sustainable Systems Analyst



AEI | AFFILIATED ENGINEERS, INC.
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P: 608.236.1175 | F: 608.238.2614
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From: Jean Marais [mailto:jeannieboef at gmail.com]
Sent: Wednesday, September 05, 2012 6:39 AM
To: TRNSYS-users at cae.wisc.edu
Subject: [TRNSYS-users] Coil ByPass Fraction

Dear Group,

I would love to know how you go about assigning the parameter "coil bypass fraction" for cooling coils that cool air. This parameter must be affected by the physical coil dimensions (pipe diameter, fins, number of rows, etc.) as well as by mass flow rate of the air and the overall dimensions of the coil. I've never seen this on a manufacturer's data sheet. Please advise.

Regards,

Jean.

PS I had hoped this was internally calculated without user input.
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