Air Duct Sizing - SI & Imperial Units

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2	Air Duct Sizing - SI & Imperial Units
3	This spreadsheet template can be helpful when calculating dimensions and pressure loss in air duct systems.
4	- Equal Friction Method			https://www.engineeringtoolbox.com/equal-friction-method-d_1028.html
5	- Velocity Method			https://www.engineeringtoolbox.com/sizing-ducts-d_207.html
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7	How to use:
8	1. Use "File" menu above to make your own editable copy of this document. You are free to use the copy as you want!
9	2. Select the table with the units you want to use - delete the lines with the other table
10	3. Make a simplified sketch for the system you want to calculate
11	4. Add the sections to the table - insert new lines by selecting similar lines - right click and copy the lines - right click and insert the lines above/below where you want it - paste in the copied line
12	5. Add volume flows for terminals - add sumarized formulas for the volume flows in the main sections
13	6. Add duct diameters
14	7. Add sumarized minor dynamic loss coefficients for each seaction
15	8. Add the pressure loss paths from node 0 to the end of all terminals - connect the pressure drops in each section - summarize the pressure drops for each path
16	9. Evaluate the velocities and pressure losses for each section and for the total system to your criteria - modify duct sizes if necessary
17	10. Add pressure loss in dampers to balance the system - the total pressure drop for all paths should be close
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19	Project:
20	Date:
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22	SI - Units
23	Air density:	1.2	(kg/m3)
24	Section	Length (m)	Airflow (m3/s)	Diameter (mm)	Velocity (m/s)	Friction Loss (Pa/m)	Friction Loss Section (Pa)	Minor Dynamic Loss Coeff. (ξ)	Minor Dynamic Loss Section (Pa)	Pressure Loss Damper (Pa)	Total Pressure Loss (Pa)	Pressure Loss Path 0-1-2 (Pa)	Pressure Loss Path 0-1-3-4 (Pa)	Pressure Loss Path 0-1-3 5 (Pa)
25	0-1	20	3	800	6.0	0.45	9	2.6	56		65	65	65	65
26	1-2	20	1	500	5.1	0.59	12	1.3	20	18	50	50
27	1-3	10	2	800	4.0	0.21	2	1	10		12		12	12
28	3-4	10	1	500	5.1	0.59	6	2	31		37		37
29	3-5	15	1	500	5.1	0.59	9	2	31		40			40
30												115	113	116
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32	Imperial - Units
33	Section	Length (ft)	Airflow (cfm)	Diameter (in)	Velocity (ft/min)	Friction Loss (in H2O/ft)	Friction Loss Section (in H2O)	Minor Dynamic Loss Coeff. (ξ)	Minor Dynamic Loss Section (in H2O)	Pressure Loss Damper (in H2O)	Total Pressure Loss (in H2O)	Pressure Loss Path 0-1-2 (in H2O)	Pressure Loss Path 0-1-3-4 (in H2O)	Pressure Loss Path 0-1-3 5 (in H2O)
34	0-1	66	6360	30	1296	0.000707	0.047	2.6	0.27		0.32	0.32	0.32	0.32
35	1-2	66	2120	20	972	0.000671	0.044	1.3	0.08	0.09	0.21	0.21
36	1-3	33	4240	30	864	0.000327	0.011	1	0.05		0.06		0.06	0.06
37	3-4	33	2120	20	972	0.000671	0.022	2	0.12		0.14		0.14
38	3-5	50	2120	20	972	0.000671	0.034	2	0.12		0.15			0.15
39												0.53	0.52	0.53
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