Ashrae Duct Fitting Database 2016 ((better)) «ORIGINAL – FULL REVIEW»

For loss: [ C_m = \frac\Delta P_mainP_v,main ]

| Parameter | Symbol | Range | Unit | |-----------|--------|-------|------| | Main duct diameter | D₁ | 200 – 1000 | mm | | Branch inlet diameter | D₂ | 100 – 600 | mm | | Branch outlet diameter (at junction) | D₃ | 0.5×D₂ – 1.0×D₂ | mm | | Conical transition length | L_c | 1.0×D₂ – 3.0×D₂ | mm | | Entry angle (branch axis to main axis) | θ | 45° | degrees | | Area ratio (branch/main at junction) | A_r | 0.1 – 0.8 | dimensionless | | Main-to-branch velocity ratio | V_r | 0.5 – 2.5 | dimensionless | ashrae duct fitting database 2016

Using the is not as simple as looking up a static number. The loss coefficient (C) is a function of dimensionless ratios. Here is a step-by-step workflow: For loss: [ C_m = \frac\Delta P_mainP_v,main ]

: It allows engineers to build a "project file" where individual fitting losses are added together to determine the total resistance of the most critical path (longest route) in the system. Technical Features Visual Interface Technical Features Visual Interface The 2016 database allows

The 2016 database allows engineers to see the drastic difference in $C$ values between a mitered elbow without vanes ($C \approx 1.3$) and a smooth radius elbow with a long radius ($C \approx 0.15$). This data drives design decisions that save energy.

The pressure drop (ΔP) is calculated as:

: Users enter dimensions (width, height), radius ratios, airflow (CFM or L/s), and air density.