Static Regain Method Duct Design

Loading Unsubscribe from Professor kartik? What is Static Regain? - Duration: 4:14. Design methods for duct loop have however not been well known and there are many design variants P (5). Installation time is reduced compared to rectangular ductwork. learner sketch duct layout. rectangular ductwork; Duct heat gain; Fitting efficiency; Duct design rules; Typical duct layout errors; High-velocity VAV duct design fittings; Static pressure sensor location. 1 Duct Sheet Metal Thickness 20 9. of air to be delivered to the diffusers from the point of entry of supply air. Duct design considerations and sizing methods 0. DUCT DESIGN METHODS Duct design methods for HVAC systems and for exhaust systems conveying vapors, gases, and smoke are the equal friction method, the static regain method, and the T-method. Equal friction method is used to design the duct, which is simple method as compared with the other design methods. o Fan selection & Static pressure calculation. Initially, you load a background drawing. Be a professional at HVAC by getting HVAC Training in Bangalore with Excelmep, the best institute in Bangalore for the HVAC courses. HVAC and Electrical System Design. This means the duct design must have an even static pressure from the first diffuser take off. Our library is the biggest of these that have literally hundreds of thousands of different products represented. Your HVAC system is made up of duct-work, filters, dampers, and mechanical HVAC equipment to mention just a few. The owner has ruled out the static regain method. Static Regain in Lossless Duct System However, both ductwork and fittings introduce friction. Use leak-tight, aerodynamic round duct designed using static regain to reduce fan load and duct pressure. Initially, you load a background drawing. design a duct system by using nomograms developed from the method as designing tools. P) calculation for selection of motor and fan. No matter how well an overall design, one flaw can significantly cripple an entire system. Materials of duct. PRESSURE LOSSES IN AIR DISTRIBUTION SYSTEM. minimizing this problem, a proper design of duct is needed. Static regain The next section is an expansion – in a real application the duct may change shape to pass around an obstacle, to join a device (such as a fan) or, indeed, the expansion may be there to alter the pressure characteristics in the duct. o Supply & Return Duct configuration, Assigning Velocity of Air (FPM) to each Section of Supply and Return Duct Low Velocity system, Medium Velocity System and High. Duct Material & Gauge Selection. Duct sizing calculations include constant pressure drop, constant velocity, and static regain. If you want to become a master learn the static regain method for a duct sizing. The essential point is a designer must recognize that no matter what methods have been applied to calculate the vent system (equal friction, velocity reduction, static regain, or constant velocity, etc. Three duct design methods are presented in the 1997 ASHRAE Handbook- Fundamentals: equal friction, static regain, and the T-method. Fabric ducting is typically designed with the static regain method. Local pressure losses are caused by the fluid flow through the duct fittings: which change the direction of the flow (elbows, bands, etc. A primary thermostat for each zone controls the four perimeter zones. Duct Designing methods (Manual calculations) : Equal friction method, Velocity reduction method, Static regain. Calculate our quick test and see what you come up with. Three methods are presented: equal friction, static regain, and the T-method. This paper gives an improved static-regain method on the basis of Gain-Loss Balance Equation which the author has derived. Our library is the biggest of these that have literally hundreds of thousands of different products. Textile Air Dispersion (TAD) systems with and without an internal frame. Learning about the various duct sizing methods, including the velocity method, equal friction method and static regain method. Material cost of duct design in static regain method is 14 percent higher from equal friction method. Duct calculation methods • Static regain method Duct size to have equal static pressure in the beginning and in the end of each section To determine the suitable standard duct size the equation should be satisfied. Recommended G. The Marquess Mechanical Department offers comprehensive experience in the design of mechanical systems including health care facilities, laboratories, office buildings, schools, industrial food processing, cold storage, industrial process, churches and luxury homes. velocity reduction, T-method, extended plenum, constant velocity, static regain), none are widely used by designers and are beyond the scope of this training mod-ule. 1 Velocity reducing method* In this velocity reduction duct design method, the factor control is the0air0velocity in the duct. Static regain method ง. Shapes of duct. The next section is an expansion - in a real application the duct may change shape to pass around an obstacle, to join a device (such as a fan) or, indeed, the expansion may be there to alter the pressure characteristics in the duct. View Ali Raza’s profile on LinkedIn, the world's largest professional community. ζ…locallosscoefficient(experiments-seeIdelchik1986) Bordalossprediction Local pressure losses 2 m d 2 w. Textile Air Dispersion (TAD) systems with and without an internal frame. The loop is fed by four or more ducts radiating out from the central plenum. This design methodology sizes the supply duct system to obtain uniform static pressure at all branches and outlets. Practical for simple systems Duct Calculators Design Methods Overview. External static pressure (E. Select velocity for main and branch ducts. You can specify sizing for sections of duct using friction and/or velocity, equal friction, or static regain sizing methods. No over cooling of multiple areas to keep one person comfortable. Static Regain Method – This method commonly used for large supply systems with long ducts is a high velocity system that maintains constant static pressure before each branch or terminal. learner correctly determine air flow requirements 7. Contrary to existing methods, the generation of the layout and the duct and fan sizing are. Corrections for static pressure losses created by the test apparatus (e. The fan is usually located somewhere within the system; therefore, it is only necessary to figure the entrance loss and the duct friction loss, then select the fan directly from the tables. Design air conditioning ducts using velocity method, equal friction method or static regain method 4. the static regain technique. For this reason, duct design methods should be reconsidered for VAV systems. Material cost of duct design in static regain method is 14 percent higher from equal friction method. static bend radius: the centerline radius to which a hose is bent in a stationary installation. Duct sizing calculations include constant pressure drop, constant velocity, and static regain. Header duct size selected by the equal friction method is the same, however the branch ducts, sized by static regain is larger. The Design goes through a number of phases. Calculate our quick test and see what you come up with. Recommended G. The total pressure of any point in the ductwork represents the actual energy of the moving air at that point. WSU Engineering Services on duct seal class requirements, sealant types, and methods of sealing. It also gives the comparison between rectangular duct and circular duct. The method can be summarized to. PART 4 DIFFERENT METHOD OF DUCT DESIGN Professor kartik. Select velocity for main and branch ducts. Learning about the various duct sizing methods, including the velocity method, equal friction method and static regain method. For this post, I thought I would focus on what the basic version of the chart can do by using an example. DYNAMIC LOSSES IN DUCT 1 ) Pressure losses due to Enlargement 2 )Pressure loss due to contraction 3 ) Pressure loss at inlet and outlet of a duct 13. Static regain The next section is an expansion – in a real application the duct may change shape to pass around an obstacle, to join a device (such as a fan) or, indeed, the expansion may be there to alter the pressure characteristics in the duct. Pressure losses of fabric diffusers & ducting are very similar to those of traditional metal ducting, but also slightly different. Effect of static regain. View Ali Raza’s profile on LinkedIn, the world's largest professional community. duct system and to satisfy all design con­ straints. Ø Capable of duct designing by various methods viz, Velocity method, Equal friction method and Static regain method Preparation of layout by using SMACNA rules/DW/144. Whatever is your design approach, equal friction, static regain or constant velocity; our CAD specialists have the competence to deliver 3D CAD models for your choice of HVAC duct designs and 2D CAD shop drawings to help you carry out uninterrupted fabrication stage. 2 Velocity Reduction Method. Any design method can be used to design a duct system for almost any pressure. Duct Design Fundamentals. Static Regain is a method used to design ducting as proposed on the ASHRAE Fundamentals Handbook, 2001. Fan selection & Static pressure calculation Constant Flow & Variable Flow Air distribution system. The equal friction and static regain methods are non-optimizing meth­ ods that rely on heuristics that do not account for prevailing local economic. Using a duct calculator. Static regain method works by keeping the static pressure constant in the ductwork throughout the system. take the test. The Static Regain table provides examples of the regain for a cone with an angle of 25 degrees to 30 degrees and varying fan outlet velocities. A 6-inch-water-gain system can be designed either by equal friction — just increase the design friction rate — or by static regain — just increase the initial velocity. Sinle Duct Variable Volume Control ssemblies - Direct Diital Controls Green indicates the static Use the support method prescribed for the rectangular duct in. Times New Roman Arial blank Equation Microsoft Equation 3. Equal friction , Constant Velocity & Static regain methods. Generally uses constant pressure method. Shapes of duct. ) q = air flow rate (cfm) v= air speed (fpm) Frictional Pressure Loss. classification of duct : low, medium, high pressure. This “Equal-Friction” method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. Labor costs can be drastically reduced. INSTALL CABLE –Fabric ducts are typically suspended by horizontal cable anchored to the building. It creates static regain designs, analyzes pressure requirements, and determines a system's design leg or critical path (path of maximum static pressure requirement). The section on Indus-trial Exhaust System Duct Design presents the design criteria and procedures for exhaust systems conveying particulates. Static Regain Method The ducts are sized so the increase in static pressure at each take‐off offsets the pressure loss of the succeeding section of ductwork. Equal Friction Method Velocity Method 1. use either the equal-friction or static-regain design methodologies when sizing a duct system. Labor costs can be drastically reduced. Round/oval. Classify air conditioning ducts based on air velocity and static pressure 3. duct design methods should be reconsidered for VAV systems. StaticRegain. When sizing based on Friction and Velocity, radio buttons, Only, And, or Or, will be active in the Duct Sizing dialog box. This makes designing duct layout much easier and increases the options for siting the air handling unit. The authors discovered this phenomenon while they were developing software that implements the T-Method. Fire and smoke control for occupant safety is a major design consideration for any building and is particularly important as part of duct systems design. velocity reduction, T-method, extended plenum, constant velocity, static regain), none are widely used by; designers and are beyond the scope of this training mod­ ule. • Equipment selection: AHU’S, FCU’S. The fitting between section a and b is SD 5-10. By an analysis of a few currently used calculation procedures based on the traditional static regain duct design method, points out the problems in them and presents a new approach the efficiency of which is verified through engineering design practice in realising uniform air supply with higher calculating speed and better hydraulic balance of. Duct Design and layouts. doc Duct Design -- Equal Friction 2Jul2012 Chapter 7, Rev 1. DuctNet is a program for sizing ducting. A practical duct design problem was solved by using the proposed method as well as the classical Static Regain method (for three different values of the Regain Factor). Equal friction method. Choose between the static regain and equal friction methods of design. My most common duct design type is the "Static Regain Method", I've used some "Equal Friction Method" systems. Plot design study, Calculating the air flow to be extracted from an enclosed system and the air flow to be supplied through ducting in an enclosed system, determining the static pressure available in the duct for the best possible product selection. 8–9 Duct System Design 8–9 Design Considerations 8–12 Duct Design Methods 8–13 Duct Design Procedures 8–13 Automated Duct Design 8–14 Duct Fitting Friction Loss Example 8–14 Equal Friction Method Example 8–15 Resistance in Low Pressure Duct System Example 8–15 Static Regain Method Example 8–17 Fitting Loss Coefficients. 1 Duct Sheet Metal Thickness 20 9. 1 MB, Price: USD $840. Learn more about Technical Committees at ashrae Ashrae handbook fundamentals duct design. Simple HVAC systems can be designed employing a number of methods, including the equal friction method, the constant velocity method, the velocity reduction method, and the static regain method. local duct construction method to enable users for widely use of the program. The centerline velocity of this primary jet in any zone is related to the initial velocity (See. 82 cm was designed for stigma separation of saffron flower from the other parts. Explanation: This method is the most accurate but take lots of time for calculation. Introduce computer programming and basic numerical methods. Static Pressure is resistance against air. Any design method can be used to design a duct system for almost any pressure. Duct design methods are presented in the 1997 ASHRAE Handbook-Fundamentals. You can let the program size all the ducts for you (using three different sizing methods), or enter your own. Velocity in the main duct leaving the fan is selected first. High static pressure and filtering options may be selected. Pressure drop in the duct system can also be calculated. local duct construction method to enable users for widely use of the program. Back to Basics: Duct Design Static Regain • Supply air only depending on the proposed fire rating method. Inputs to the program are single line path of duct system and flowrates at air terminals. In fittings, friction losses are caused by the. Metal Duct. We have chosen to keep it simple with an equal-friction comparison. Static regain method ง. The desired width is dependent upon the traffic volumes and speeds, and on the roadside geometry. Introduction 2. • Types of ducts, Duct fittings, Dampers, Types of diffusers, Flexible ducts etc. The next section is an expansion - in a real application the duct may change shape to pass around an obstacle, to join a device (such as a fan) or, indeed, the expansion may be there to alter the pressure characteristics in the duct. DUCT DESIGN METHODS Duct design methods for HVAC systems and for exhaust systems conveying vapors, gases, and smoke are the equal friction method, the static regain method, and the T-method. • Ducts reducer selection • Duct gauge selection and number of sheet calculation • Duct designing methods (manual calculations) using. The tapered end of the silencer baffle/bullet allows for static regain to occur, thereby offering the lowest silencer pressure drop for a particular level of attenuation. Shapes of duct. Tools for duct design and commissioning. duct systems to investigate the impact of varying airflow rates on the sizing of duct systems. 1 Zoning 22 10. One setting that we added in the latest release for static regain is the minimum velocity value. No matter which method is used, the size of the space to be heated or cooled by the air conditioning duct has to be known. vi) Avoid duct obstructions. Duct-Definition and types; Materials of Duct and its specification (Gauge) Duct design consideration for Duct sizing as per Aspect Ratio; Duct size method Equal Friction method Velocity reduction method. Financial acc ounting and inventory management software is an easy to use and powerful utility designed for both small and large scale business enterprises to. Building load calculations are done using the ASHRAE CLTD method and compare favorable with other loads programs such as Elite…. It is written to work the way an engineer works, providing flexibility in design and increased productivity. But static regain does not automatically design systems at a lower total pressure. Covers information pertaining to VAV duct design with special attention given to the static regain method. There of the duct dimensions will. materials of duct. learner correctly determine air flow requirements 7. Our library is the biggest of these that have literally hundreds of thousands of different products represented. This section is sized at the maximum velocity you have specified. When using the static regain method ducts are designed so that the available static pressure is used to offset the friction loss on the subsequent section of duct. Any design method can be used to design a duct system for almost any pressure. Pressure losses of fabric diffusers & ducting are very similar to those of traditional metal ducting, but also slightly different. Air Velocity Measurement 6. velocity reduction, T-method, extended plenum, constant velocity, static regain), none are widely used by designers and are beyond the scope of this training mod-ule. • Pressure losses in fittings, due to sudden enlargements, contractions etc. 1 Fan Free or abrupt discharge into plenum results in a reduction in fan performance. Coming back to my difficulty in the capability of the Varitrane Duct Sizing Software that it does not calculate the duct sizes downstream of the VAVs. , there will be. Plot design study, Calculating the air flow to be extracted from an enclosed system and the air flow to be supplied through ducting in an enclosed system, determining the static pressure available in the duct for the best possible product selection. Loading Unsubscribe from Professor kartik? What is Static Regain? - Duration: 4:14. BY PATRICK J. velocity reduction method 1. ) q = air flow rate (cfm) v= air speed (fpm) Frictional Pressure Loss. Equal friction method is used to design the duct, which is simple method as compared with the other design methods. Static regain method ง. Where fittings of configurations not shown in the HVAC-DCS are shown on the contract drawings, they shall be constructed as though they were therein. Ø Supervising installation of Primary & secondary Pumps, Valve package, Pressure maintaining group, Chemical Dosing etc. drop in the succeeding. Equal friction , Constant Velocity & Static regain methods. duct system and to satisfy all design con­ straints. Duct Material Calculation- GI sheet, Total sheet required in kgs. with static regain method duct design. Good duct design can result in first cost savings, substantial operating cost savings, and lower noise levels by minimizing and equalizing static pressure throughout the system. One setting that we added in the latest release for static regain is the minimum velocity value. When measuring static pressure, the unit of measurement. The length of straight duct between sections b and c is 10 m. Static Regain The static regain method of duct sizing is a more complex and detailed method and may be used to size supply duct systems o f any pressure/velo city class. Static pressure 101 Static pressure is the amount of pressure a fan has to push and pull against to move air through a duct system. The total pressure of any point in the ductwork represents the actual energy of the moving air at that point. inlet to the discharge of a duct element. Problems with the Static Regain method Problems with the Static Regain method Mathews, E. According to the design guide noted in that link it is not a totally valid method. ; Claassen, D. Residential Duct Sizing Guide The following duct sizes are based on a friction rate of. a higher static pressure and optional high efficiency filters. velocity reduction, T-method, extended plenum, constant velocity,static regain), none are widely used by designers and are beyond the scope of this training. The System Inspector and how it can supplement the Duct and Pipe Pressure Loss Reports. The results are then compared with those obtained from static regain method. HVAC SYSTEMS DUCT DESIGN SHEET METAL The pressure due to the weight of a fluid above the point of measurement Static Regain Method: A method of duct sizing. Any design method can be used to design a duct system for almost any pressure. of air to be delivered to the diffusers from the point of entry of supply air. * Duct systems were laid out for the least possible resistance to the most remote point. Most commonly used methods for simpler lay-outs. static conductive: having the capability of furnishing a path for a flow of static electricity. Pressure losses of fabric diffusers & ducting are very similar to those of traditional metal ducting, but also slightly different. provided with an inlet or discharge plenum and a suitably sized duct shall extend from the plenum. Using a duct-static-pressure reset (SPR) control strategy to reduce duct static pressures (so that at least one terminal box damper is nearly fully open) has the potential to save as much fan energy as does sealing supply duct leaks. Problems with the Static Regain method Problems with the Static Regain method Mathews, E. Recommended G. Design Master HVAC is an integrated HVAC building design and drafting program for AutoCAD. Technicians will learn how to spot problems with leaking ducts. Static Regain Method เหมาะกับท่อลม ความเร็วสูง (สูงกว่า 2000 fpm) หลักการง่ายๆ คือ เลือก ขนาดท่อลมให้ได้ Regain อันเนื่องมาจากการลดความเร็วลม ลง ณ. Duct sizing calculations include constant pressure drop, constant velocity, and static regain. In straight duct, friction losses are due to fluid viscosity and are the result of momentum exchange between molecules in laminar flow. This ensures that the static pressure available at the end of each branch is equal throughout the system resulting in equal airflow at each terminal. Fans that. Static regain method ง. PRESSURE LOSSES IN AIR DISTRIBUTION SYSTEM. Types, sizing & selection of Air Terminal Devices (Grilles, Diffusers & Registers). 33 GUIDE FOR INSPECTING CAPTURE SYSTEMS AND CONTROL DEVICES AT SURFACE COATING OPERATIONS Draft Final Report May 1982 Prepared by Robert G. Member ASHRAE Herman F. Prefabrication duct modeling helps determine the right duct size, duct work routing, and the correct type and amount of construction material required. Current design guides provide design methods and data for the prediction of pressure losses only for a single and isolated fitting. Air Distribution Systems Part A] Ducts Classification of ducts, duct material, pressure in ducts, flow through duct, pressure losses in duct (friction losses, dynamic losses), air flow through simple duct system, equivalent diameter, Methods of duct system design : equal friction, velocity reduction, static regain method (numerical on duct. Room areas are calculated from the drawing, eliminating data entry errors. is a good basis to follow for noise critical environments. Platform: Windows. The other two methods are rarely used in the HVAC industry. Air Duct System & Sizing Fundamentals of Air Flow in Duct Bernoulli Equation: streamline flow of ideal fluid with no frictional loss p v2 + + gz = constant ρ 2 P = static pressure ρ = density v = velocity z = height above datum Fundamentals of Air Flow in Duct Application of Steady Flow Energy Equation: taking into account viscosity and losses of real fluids: P1 v1 P2 v 2 + + gz 1 = + + gz 2. Duct Material & Gauge Selection. • Discharge Duct Turns Rotation Rotation straight duct Length of ( at least 3 equivalent duct Ø ) GOOD POOR • Non-Ducted Inlet Clearance • Free Discharge is not realized. The length of that duct is 5m, and so the pressure drop is 5 x 1. Inputs to the program are single line path of duct system and flowrates at air terminals. There set practical sizes and duct dimensions will be calculated. Price: $840Product DescriptionDesign Master HVAC is an integrated HVAC building design and drafting package for AutoCAD. Contrary to existing methods, the generation of the layout and the duct and fan sizing are. Header duct size selected by the equal friction method is the same, however the branch ducts, sized by static regain is larger. A properly designed duct system is critical to the success of a HVAC system. Figure A, connects the fan to a larger duct resulting in static regain. Unfortunate the method is complicated to use and therefore seldom used. Covers information pertaining to VAV duct design with special attention given to the static regain method. Calculate our quick test and see what you come up with. 1 Duct Sheet Metal Thickness 20 9. While this is a balanced system as it does not involve dampering, longer ducts may affect air distribution to conditioned spaces. 1 MB, Price: USD $840. The length of straight duct between sections b and c is 10 m. Analysis of existing ductwork. Good duct design can result in first cost savings, substantial operating cost savings, and lower noise levels by minimizing and equalizing static pressure throughout the system. When sizing based on Friction and Velocity, radio buttons, Only, And, or Or, will be active in the Duct Sizing dialog box. Classify air conditioning ducts based on air velocity and static pressure 3. Return air design An Example of Static Regain. 0 Photo Editor Photo Announcement Objectives Duct design (part of the HVAC Design successfully integrated into BIM) Pressures Relationship Between Static and Total Pressure Duct design method (defines the layout) System Characteristic Duct Design Frictional Losses (in a staring round. This is possible if the friction loss in each run is made equal to the pressure gain due to reduction in velocity. Duct sizing calculations include constant pressure drop, constant velocity, and static regain. Duct designing methods (manual calculations) using - Equal friction method, Velocity reduction method, Static regain method. We have chosen to keep it simple with an equal-friction comparison. Duct Designing using : a) formulae [Static Regain, Equal Friction, Velocity Reduction] (b) using Ductulators and (c) using software programs (DUCTO, McQuay, Duct Checker). Duct sizing calculations include constant pressure drop, constant velocity, and static regain. For the static regain method, the large cross-sectional area of air duct has a large static pressure. Revit doesn't have any built-in functionality to help size duct by static. Static Regain Method The ducts are sized so the increase in static pressure at each take-off offsets the pressure loss of the succeeding section of ductwork. 20 Schematic for Example 7; Fig. through the supply duct plus the entrained room air that lies within an envelope of arbitrary velocity, usually taken as some value between 50 and 150 fpm. Guither, PE, BEMP, LEED AP O+M ACEC of MN – Building Engineering & Construction Conference Track 1. o Supply & Return Duct configuration, Assigning Velocity of Air (FPM) to each Section of Supply and Return Duct Low Velocity system, Medium Velocity System and High. drop in the succeeding. Air Velocity Measurement 6. Conversion of hydraulic diameter to rectangular ducts. 1Equal Friction Method หลักการออกแบบท่อลมวิธีนี้ ให้ท าการก าหนดค่า Frictionrate ที่เหมาะสมเป็นค่าคงที่. Your HVAC system is made up of duct-work, filters, dampers, and mechanical HVAC equipment to mention just a few. 2 Velocity Reduction Method 17 8. The other two methods are rarely used in the HVAC industry. Duct Deigning basics (types, gauge selection, duct comparison and fabrication procedure etc. Denotes CA Station location. The Equal Friction Design Method. Velocity Method: A mean velocity is chosen for a section of the system. com There are two main methods for determining the proper duct size for a heating, ventilation, and air conditioning system. Constant velocity. Cedengineering. 25" static pressure regain available to offset the frictional losses in the duct. Design air conditioning ducts using velocity method, equal friction method or static regain method 4. use either the equal-friction or static-regain design methodologies when sizing a duct system. Usually, the duct velocity is determined before the size of the duct is selected. If you want to become a master learn the static regain method for a duct sizing. Preparation before duct. • Responsible for reviewing shop drawings of HVAC, Plumbing and Fire Fighting systems. Features include 2D and 3D ductwork drafting, ductwork sizing, pressure drop calculations, and building load calculations. Identify considerations and requirements used to determine duct system design. Pressure drop in the duct system can also be calculated. The latest ASHRAE Fundamentals Handbook, 2009, continues to list equal friction as a viable duct design method, along with static regain and "T-method". A proper Manual D duct design with Right-D ® will help to quickly find which fan, coil and filter combinations will work together to achieve optimal results and best suit you and your. Drafting features include single-line and double-line 2D ductwork with automatic fittings and 3D ductwork. For this reason, duct design methods should be reconsidered for VAV systems. 100% placements are assured with our institute. Static Regain *Improved* This design methodology sizes the supply duct system to obtain uniform static pressure at all branches and outlets. & Duct Support, Reservation of Duct Pipe. This program will size, price and produce a complete cutting list of the Duct. mcgillairflow. Air flow through simple duct system Duct design methods: Equal Friction, Velocity Reduction, Static Regain About Speaker Prof. Drone attacks claimed by Yemen’s Houthi rebels have caused fires at two major facilities run by Saudi Aramco, Saudi arabia ‘s state-owned oil giant. In considering these aspects, practical guidelines for good design and installation are provided. Duct Material Calculation- GI sheet, Total sheet required in kgs. Once the design data has been transferred, use Trace 700 to perform heating and cooling load analyses, and Varitrane Duct Designer and Elite Ductsize to calculate optimal duct sizes using the static regain, equal friction, or constant velocity method. size the ducts according to the following design procedures: constant friction, constant-velocity or static-regain. Simple HVAC systems can be designed employing a number of methods, including the equal friction method, the constant velocity method, the velocity reduction method, and the static regain method. proper design of duct is needed. The Static Regain table provides examples of the regain for a cone with an angle of 25 degrees to 30 degrees and varying fan outlet velocities. Static Regain Method - This method commonly used for large supply systems with long ducts is a high velocity system that maintains constant static pressure before each branch or terminal. 1 Duct Sheet Metal Thickness 20 9.