Duct Sizing Excel Program
HVAC System Design The Sequential Process for Calculating Loads, Sizing Appliances & Designing. Trunk and reading the size off the duct sizing scale.
- This calculation program on Excel makes it possible to dimension and carry out the calculation of the pressure losses on the ductworks and air distribution.
- HVAC Calculations and Duct Sizing 2012 Instructor: Gary D. Beckfeld, P.E. PDH Online PDH Center 5272 Meadow Estates Drive Fairfax, VA.
- The Duct Size Calculator is a quick reference tool for approximating duct sizes and equivalent sizes of sheet metal duct vs. Flexible duct. The calculator uses information from ASHRAE Research Project 1333, HVAC Duct Efficiency Measures, and was developed with funding support from ASHRAE and ADI.
- Duct sizing, Duct size, Static pressure. This calculation program on Excel makes it possible to dimension and carry out the calculation of the pressure.
- Rapid HVAC Duct Sizing Free. Sipols Software. Find out where you sit on the political spectrum & learn different philosophies. Rapid HVAC Pipe Sizing.
The velocity reduction method can be used for sizing air ducts
The Velocity Reduction Method can be used when sizing air ducts. The method can be summarized to
- Select suitable velocities for main and branch ducts from the table below
- Find the sizes of main and branch ducts from the air flow rates and the velocities by using eq. 1 and the charts below
- From velocities and duct dimensions - find the frictional pressure loss in the main and branch ducts using the friction chart below
- Add minor dynamic loss
Proper Velocities
A proper velocity depends on application and environment. The table below indicate commonly used velocities:
Type of Duct | Comfort Systems | Industrial Systems | High Speed Systems | |||
---|---|---|---|---|---|---|
m/s | ftm | m/s | ftm | m/s | ftm | |
Main ducts | 4 - 7 | 780 - 1380 | 8 - 12 | 1575 - 2360 | 10 - 18 | 1670 - 3540 |
Main branch ducts | 3 - 5 | 590 - 985 | 5 - 8 | 985 - 1575 | 6 - 12 | 1180 - 2360 |
Branch ducts | 1 - 3 | 200 - 590 | 3 - 5 | 590 - 985 | 5 - 8 | 985 - 1575 |
Be aware that high velocity close to outlets and inlets may generate unacceptable noise.
Velocities commonly used for different applications:
- upstream medium pressure VAV boxes: 2000 to 2500 fpm (10 - 13 m/s)
- transport of fumes, mist or very light particulates: 2400 fpm (12 m/s)
- dust collection systems with small particulate: 3500 fpm (18 m/s)
- dust collection systems with heavy particulate like metals: 5000 fpm (25 m/s)
Sizing Ducts
Sizes of ducts are then given by the continuity equation like:
A = q / v (1)
where
A = duct cross sectional area (m2)
q = air flow rate (m3/s)
v= air speed (m/s)
Alternatively in Imperial units
Ai = 144 qi / vi (1b)
Qbert download free. where
A = duct cross sectional area (sq.in.)
q = air flow rate (cfm)
v= air speed (fpm)
Frictional Pressure Loss
Estimate friction loss in main and branch ducts from the charts below:
Air Ducts Sizing Spreadsheet Template
Air Ducts Spreadsheet Template - The Velocity Method
Free Excel Program
The velocity method can be done manual or more or less semi automatic with the spreadsheet template below.
This template is based on the in the spreadsheet. Customize sections, airflows, duct sizes and minor dynamic loss coefficients - add pressure loss paths and evaluate and reconfigure the system to fit your criteria. Summarize pressure loss for each path and add damper pressure losses manually to balance the system.
The Google Docs spreadsheet template can be opened and copied here! The spreadsheet can also be downloaded as an excel file. Use the Google Docs 'File' menu on the top of the template.
Insert air ducts to your Sketchup model with the Engineering ToolBox Sketchup Extension
Related Topics
Cfm Duct Sizing Chart
- Ventilation - Systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more
Related Documents
- Air Ducts - Friction Loss Diagram - A major loss diagram for air ducts - Imperial units ranging 10 - 100 000 cfm
- Air Ducts - Sizing - Air flow and required duct area
- Air Ducts - Velocity Diagram - Air flow volume, duct size, velocity and dynamic pressure
- Design of Ventilation Systems - Design procedure for ventilation systems - air flow rates, heat and cooling loads, air shifts according occupants, air supply principles
- Duct Sizing - Equal Friction Method - The equal friction method for sizing air ducts is easy and straightforward to use
- Duct Velocity - Calculate velocities in circular and rectangular ducts - imperial and SI-units - online calculator
- Ducts - Diameter and Cross-Sectional Area - Circular ducts and cross-sectional areas
- Ductwork Support - Ductwork support and recommended distance between hangers
- Dynamic Pressure - Dynamic pressure is the kinetic energy per unit volume of a fluid
- Equation of Continuity - The Equation of Continuity is a statement of mass conservation
- Equivalent Diameter - Rectangular and Circular HVAC Ducts - Equivalent diameter for rectangular and circular ducts - air flows between 100 - 50000 cfm
- Friction Head Loss in Air Ducts - Online Calculator - Head loss or major loss in air ducts - equations and online calculator for rectangular and circular ducts - Imperial and SI units
- HVAC Abbreviations - Commonly used HVAC abbreviations
- Noise Generated in Air Ducts - Noise generated form air flow in ducts
- Pressure Classifications of Duct Systems - Duct systems are commonly divided into three pressure classifications
- Sizing Circular Ducts - A rough guide to maximum air volume capacity of circular ducts in comfort, industrial and high speed ventilation systems
- Spiral Ducts - Dimensions - Standard dimensions of spiral ducts - Imperial units
- Typical Air Duct Velocities - Typical air duct velocities in applications like ventilation systems or compressed air systems
- Velocity Classification of Ventilation Ducts - Recommended air velocities in ventilation ducts
Compressed Air Pipe Sizing Excel
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