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Pipes/Ducts

This section details the pipe/duct calculations and how each result is determined.

These calculations are influenced by Methods, Systems, the drawing layout, and the Properties of the Pipes and the connections to the Pipes.

Height Above Floor

The Height Above Floor refers to the vertical distance of a Pipe/Duct segment above the floor Level.

This property is critical for determining the pressure changes within the system due to elevation differences.

Influences of Height Above Floor:

The following influence the Height Above Floor:

  • Floor Level Height: The Height of the Floor Level.

  • Pipe/Duct Segment Elevation: The specific Height of the Pipe/Duct segment above the designated Floor Level.

  • Equipment/Fixture Connection Heights: Heights of connected Equipment, Emitters, Terminals, or Fixtures that influence the overall pressure calculation.

Troubleshooting Height Above Floor:

  • Check Floor Level Settings:

    • Ensure the floor levels are correctly set in the Project Properties.

  • Verify Pipe/Duct Segment Elevations:

    • Review the Height values of each Pipe/Duct segment in their Properties tab.

    • Confirm they match the intended elevation in the Design.

  • Inspect Equipment and Fixture Heights:

    • Ensure connected Equipment, Emitters, Terminals, or Fixtures have accurate Height values defined.

  • Use Heat Maps:

    • Identify areas where Height variations may cause significant pressure changes.

  • Analyze Design Report:

    • Export the Design Report Spreadsheet and check for anomalies in heights.

Peak Flow Rate (Water)

The Peak Flow Rate in a domestic water system represents the maximum expected flow rate, calculated as the combined demand across all connected Fixtures and Nodes. 

Influences of Peak Flow Rate:

  • Peak Flow Rate Calculation Method: This setting specifies the calculation standard or method used to derive the Peak Flow Rate. 

    • This setting is defined in Methods.

    • Diversification adjusts flow requirements to reflect realistic peak demand rather than the maximum possible flow for every fixture. For example, in a residential system, not all fixtures will be used simultaneously; diversification accounts for this by applying a factor that reduces total calculated demand.

  • Loading/Fixture Units of Fixtures and Nodes: Each connected Fixture or Node has an assigned loading or fixture unit value, representing its contribution to peak flow based on expected usage.

    • This unit is assigned to each Fixture or Node in the Design phase.

    • Higher loading units increase the Peak Flow Rate, as these units are summed across all connected Fixtures to determine total demand.

  • Continuous Flow Fixtures/Nodes: Fixtures or Nodes that operate with a continuous flow (such as certain medical equipment) that bypass Diversification. Instead, their flow rates are added directly to the peak flow rate calculation, representing a constant demand that does not vary.

    • Identified as continuous flow within node or fixture properties.

    • Continuous flow fixtures add directly to the peak flow rate without diversification, ensuring that the calculation fully accounts for constant demands.

  • Spare Capacity: An optional setting that adds a percentage increase to the peak flow rate for future demand or unexpected increases. Adding Spare Capacity ensures the system can handle higher-than-anticipated flows without the risk of undersizing.

    • Configurable in System Settings as a percentage added to the final peak flow rate.

    • Spare Capacity increases the peak flow rate by a specified percentage, providing a buffer for demand fluctuations or future system expansions.

Peak Flow Rate is crucial for determining appropriate pipe sizing, system pressure requirements, and equipment capacity. By calculating the maximum expected demand, this metric helps ensure that the system can meet peak water requirements without performance issues.

Troubleshooting of Peak Flow Rate:

  1. Review the Water section of Methods

  2. Review the relevant Systems

  3. Export a Design Report and review all of the Fixture/Node values

Peak Flow Rate (Ventilation)

The Peak Flow Rate in a ventilation system represents the maximum expected flow rate, calculated as the combined demand across all connected Diffusers/Grilles.

Influences of Peak Flow Rate (Ventilation):

  • [Optional] Vent Air Changes Rate Standard: This setting specifies the calculation standard or method used to derive the Peak Flow Rate. 

    • This setting is defined in Methods.

    • Each Room typically has a different minimum ventilation flow rate requirement.

  • Diffuser/Grille Flow Rate Method: This defines the flow rate in each specific Diffuser/Grille, and there are the following options available:

    • Manual: Manually select the desired flow rate.

      • If you are not using h2x for ventilation flow rate calculations (by drawing the building footprint, etc.), then you will need to use this one.

    • If you have completed your ventilation flow rate requirements in h2x, in addition to manually entering your flow rates, you have the following options:

      • Share Units: Distributes the building's total required flow rate evenly among all units.

        • Total building flow rate: 100 GPM

        • Diffusers: 4 

        • Flow rate per unit: 25 GPM each (even distribution).

      • Percentage: Allows you to set a specific percentage of the total building flow rate to allocate.

        • Total building flow rate: 100 GPM

        • Allocated percentage: 60% to Diffuser A, 40% to Diffuser B

        • Flow rate: Diffuser A = 60 GPM, Diffuser B = 40 GPM.

      • Room: Aligns with the specific flow rate required by each room.

        • Room A requires 30 GPM, Room B requires 20 GPM, Room C requires 50 GPM.

        • Flow rate aligns exactly with each room's requirement: Diffuser in Room A = 30 GPM, Diffuser in Room B = 20 GPM, Diffuser in Room C = 50 GPM.

      • Room Size: Matches the required flow rate of each room, and distributes any remaining building flow rate proportionally based on room area.

        • Total building flow rate: 120 GPM

        • Room A = 200 sq. ft., Room B = 200 sq. ft., Room C = 400 sq. ft., Room D = 400 sq. ft.

        • Base flow rate: Room A = 20 GPM, Room B = 20GPM, Room C = 40GPM.

        • The shared flow for Room D (40GPM) was distributed proportionally: Room A = 10 GPM, Room B = 10 GPM, and Room C = 20 GPM.

        • Final flow rates: Room A = 30 GPM, Room B = 30 GPM, Room C = 60 GPM.

  • Spare Capacity: An optional setting that adds a percentage increase to the peak flow rate for future demand or unexpected increases. Adding spare capacity ensures the system can handle higher-than-anticipated flows without the risk of undersizing.

    • Configurable in System Settings as a percentage added to the final peak flow rate.

    • Spare capacity increases the peak flow rate by a specified percentage, providing a buffer for demand fluctuations or future system expansions.

Peak Flow Rate is crucial for determining appropriate pipe sizing, system pressure requirements, and equipment capacity. By calculating the maximum expected demand, this metric helps ensure that the system can meet peak ventilation requirements without performance issues.

Troubleshooting of Peak Flow Rate (Ventilation):

  1. Review the Mechanical section of Methods

  2. Review the relevant Systems

  3. Export a Design Report and review all of the Diffuser/Grille values

Loading Units/Water Supply Fixture Units

The Loading/Water Supply Fixture Units represent the expected demand of individual fixtures or nodes in a water supply system. These units form the basis for calculating the system's peak flow rate, reflecting realistic water usage patterns.

Influences of Loading Units/Water Supply Fixture Units:

  • Assigned Loading/Fixture Units

    • Each Fixture or Node is assigned a fixture unit value based on the selected Peak Flow Rate Calculation Method, based on its expected water demand.

    • Fixtures with higher loading units contribute more significantly to the system's total demand.

  • Diversification Factors

    • Diversification converts the sum of loading/fixture units to reflect realistic peak usage.

    • In systems like residential Water Supply, not all fixtures operate simultaneously. Diversification applies a factor to reduce total demand and prevent oversizing.

      1. As the total loading/fixture units increase, the peak flow rate grows, but the rate of increase diminishes due to the decreasing likelihood of all fixtures operating at once.

Total Heat Load (THL)

Total Heat Load (THL) represents the total amount of heat energy lost or gained within a piping system, typically measured in kilowatts (kW) or British Thermal Units (BTUs). 

This calculation quantifies the energy required to maintain the target temperature throughout the system, considering Heat Transfer through pipes and connected emitters (in mechanical systems only).

Total Heat Load is critical for accurately sizing the pipework on the recirculation system

Influences of Total Heat Load (THL):


Total Heat Load is influenced by various settings across several categories, including Pipe Specifications, Temperature Settings, Insulation Properties, System Layout, and Emitter Connections (in mechanical systems only).

Pipe Specifications

  • Pipe Material: Each Material (e.g., Copper, PVC, Steel) has a unique thermal conductivity affecting the heat transfer rate. For example, copper’s high conductivity results in faster heat loss than less conductive materials.

    • Selected in the pipe material section of the System Settings.

  • Pipe Diameter: Pipe diameter determines the surface area exposed to Ambient Conditions, influencing heat transfer rates.

    • Selected based on the parameters in the pipe sizing section of the System Settings.

Insulation Properties

  • Insulation Type: Insulation Materials like Foam and Fiberglass have distinct thermal resistances that affect their ability to retain heat within the pipe.
    High-performance insulation materials reduce heat loss efficiently.

    • Selected in insulation specifications of Systems settings.

  • Insulation Thickness: Insulation thickness increases the thermal resistance, reducing heat transfer rates. Thicker insulation retains heat more effectively.

    • Selected in insulation specifications of Systems settings.

Temperature Settings

  • Outlet Temperature: The Temperature of the Fluid as it exits the Heating or Cooling source. Higher Outlet Temperatures result in a larger temperature differential between the fluid and surroundings, driving faster Heat Loss.

    • Set in Outlets tab in the equipment’s properties and in Systems Settings.

  • Ambient Air Temperature: The surrounding air temperature impacts the pipe's heat loss rate. Lower ambient temperatures increase the temperature differential, causing faster heat transfer out of the system.

    • Set in Methods Settings.

System Layout

  • Pipe Lengths: The cumulative length and configuration of the piping impact total Heat Loss. Longer pipe runs expose more surface area to ambient conditions, increasing Total Heat Load as the fluid travels greater distances.

  • Connected Emitters (FCU, AHU, Manifolds, Radiators): Emitters extract or release heat from the system, impacting the Total Heat Load on the piping network.

Troubleshooting of Total Heat Load (THL):

  1. Review the Methods for ambient temperature

  2. Review the Systems for pipe / insulation details and temperature

  3. Review the Equipment outlet temperature

  4. Review the Emitter loads

  5. Review each Pipe Length to ensure they are correct

Recirculation Flow Rate

The Recirculation Flow Rate is the flow rate required to maintain the delta T temperature throughout the Recirculating System. 

The recirculation flow rate is derived from the Total Heat Load (THL) and the difference between the flow/outlet and return temperatures (delta T) found in the equipment properties.

Recirculation Flow Rate Formula:

Q = E / (cp × ΔT)

Where:

  • Q = Recirculation flow rate (L/s or ft³/s)

  • E = Heat energy (W or BTU/h)

  • cp = Specific heat capacity of the fluid (J/kg·K or BTU/lb·°F)

  • ΔT = Temperature difference (K or °F)

Influences of Recirculation Flow Rate:

Temperature Settings

  • Outlet Temperature: The temperature of water as it leaves the equipment. 

    • Set in Outlets tab in the equipment’s properties and in Systems Settings

  • Return Temperature: The temperature of the water when it returns to the equipment. 

    • Set in Outlets tab in the equipment’s properties

Water Properties

  • Specific Heat Capacity of Water: The energy required to raise the water temperature by one degree. This value is specific to the water’s temperature and directly affects the recirculation flow rate calculation. 

Troubleshooting of Recirculation Flow Rate:

  1. Review the Total Heat Load on the system

  2. Review the Equipment outlet and return temperature properties

  3. Review the Include Pipe Heat Load? option in the Equipment Outlet tab.
    Here you can turn off the pipe heat load from being associated with the pipe sizing, leaving just the emitter heat load on the pipe.

h2x utilizes variable Specific Heat Capacity of the fluid depending on it's temperature. Also it depends if your Heating/Chilled System uses only water as it's fluid or water mixed with specific percentage of Ethylene Glycol.

Velocity

Velocity represents the speed at which fluid moves through a pipe/duct, typically measured in meters per second (m/s) or feet per second (ft/s). 

Maintaining optimal velocity is crucial for preventing issues like noise, erosion, and excessive Pressure Drop, as well as ensuring efficient and balanced fluid flow throughout the system. 

Influences of Velocity:

  • Flow Rate: Velocity is directly proportional to Flow Rate. As flow rate increases, velocity increases.

  • Internal Diameter (ID): Velocity is inversely related to internal Diameter. Smaller diameters increase velocity for a given flow rate, as Fluid must move faster to pass through the restricted area. Larger diameters reduce velocity, allowing fluid to flow at lower speeds.

  • Maximum Velocity Setting: The system includes a maximum allowable Velocity to prevent excessive speed, which could lead to noise, vibration, and potential Pipe/Duct erosion over time. Designers can set or adjust this limit based on system requirements and material durability.

Velocity Formula:

v = Q / A

Where:

  • v = Velocity (m/s or ft/s)

  • Q = Flow rate (m³/s or ft³/s)

  • A = Cross-sectional area (m² or ft²)

Troubleshooting Velocity:

  1. Check if the Pipes/Ducts are sized with a maximum velocity setting by going to the Methods and confirming that the Pipe/Duct sizing method includes Maximum Velocity.

  2. Review the maximum velocity setting for relevant Pipes/Ducts in Systems to ensure it meets design requirements.

  3. Verify that no Pipe/Duct sizes have been disabled, as this could affect available Sizing options.

  4. Confirm that the Maximum Velocity setting hasn’t been overridden on specific Pipes/Ducts by selecting each pipe in Design mode and reviewing its Properties.

  5. Examine the Flow Rates on the Pipe/Duct to assess if high flow contributes to excess Velocity.

  6. Review the Pressure Drop on the Pipe/Duct, depending on the Pipe/Duct Sizing method. This can affect the sizing rather than just Velocity.

  7. Look at the Heat Map for Velocity, it could give you a visual indication of high or low areas.

Index Node Path

The Show Index Node Path identifies the specific route from the system's start to an outlet, focusing on the segment with the highest cumulative Pressure Drop. 

This path includes Pipes/Ducts, Equipment, changes in height, Valves, and Fittings that contribute to the pressure drop.

Influences of Index Node Path:

Flow Source (Water Systems Only)

  • Pressure & Height: The pressure at the start of the system

    • Set in Properties tab in the Flow Source

Pipe/Duct Sizing Settings

  • Sizing Parameters: The maximum allowable Velocity and/or Pressure Drop along the Pipes/Ducts in the system

    • Set in the Methods and the Systems 

Valve and Fittings

  • Pressure Drop: Each Valve and Fitting adds resistance to the overall pressure drop along the path.

    • Most valves and fittings use industry-standard defaults for resistance (K or Zeta values), which are not editable.

    • You can override these in the Properties tab if a field is available.

Equipment 

  • Pressure Drop: In the equipment properties

    • Set in the Properties of each piece of Equipment.

Elevation Changes

  • Pipe/Duct Heights: Variations in pipe/duct elevation impact pressure. Vertical segments are especially significant in determining Pressure Drop.

    • Set in the Properties of each Duct/Pipe/Riser and also the Emitter/Fixture/Equipment you are connecting to.

Troubleshooting of Index Node Path:

Step

Action

Details

1

Use Heat Maps

Visualize areas with high-Pressure Drops.

2

Inspect the Highlighted Path

Check Properties of Flow Sources, Pipe/Duct heights, Floor Level heights, and connections to Equipment, Fixtures, or Emitters.

3

Examine Pressure at Valves and Fittings

Enable pressure display for each fitting and identify segments with unusually high-pressure differences.

4

Redraw Problematic Segments

If the Pressure Drop is unexpectedly high between two points, delete and redraw the segment.

5

Review Sizing Parameters

Confirm Velocity and/or Pressure Drop Settings. Ensure they are enabled and set to appropriate levels.

6

Download the Design Report Spreadsheet

Look for anomalies or unexpected values, such as unusually high-pressure drops, incorrect Flow Rates, or mismatched component parameters.

Index Circuit

The Show Index Node Circuit identifies the segment within a recirculation system with the highest cumulative Pressure Drop, focusing on the route between Equipment and its recirculation path.

This circuit includes Pipes, Equipment, Emitters, Valves, and Fittings that contribute to the Pressure Drop.

Influences of Index Circuit:

Equipment

  • Pressure Drop: Defined in the Properties of each Equipment.

    • Set in the equipment’s Properties tab, including Recirculation settings.

Pipe Sizing Settings

  • Sizing Parameters: The maximum allowable Velocity and/or Pressure Drop along the pipes in the system.

    • Set in Methods and Systems.

Valves and Fittings

  • Pressure Drop: Resistance from Valves and Fittings adds to the overall pressure drop along the circuit.

    • Most valves and fittings use industry-standard defaults for resistance (K or Zeta values), which are not editable.

    • You can override these in the Properties tab if a field is available.

Emitters

  • Pressure Drop: Defined in the Properties of each Emitter.

    • Set in the emitter’s Properties tab.

Troubleshooting of Index Circuit:

Task

Steps

Use Heat Maps

Visualize areas with high pressure drops.

Inspect the Highlighted Path

Check properties of Equipment, Pipe Heights/Lengths, Floor Level Heights, and connections to Emitters.

Examine Pressure at Valves and Fittings

Enable pressure display for each Fitting and identify segments with unusual pressure differences. Note that Lockshield Valves or balancing devices are designed for the lowest drop on the index circuit. Each subsequent circuit will have increasingly higher pressure drops at respective Balancing Valves.

Redraw Problematic Segments

If Pressure Drop is unexpectedly high between two points, delete and redraw the segment.

Review Sizing Parameters

Confirm Velocity and/or Pressure Drop settings. Ensure they are enabled and set to appropriate levels.

Download the Design Report Spreadsheet

Look for anomalies or unexpected values, such as unusually high drops, incorrect flow rates, or mismatched component parameters.

Pipe Diameter (ø)

The nominal diameter selected for each pipe based on the design conditions.

Influences of Pipe Diameter (ø):

  • Flow Rate: The pipe Diameter is sized based on the calculated flow requirements.

  • Maximum Velocity and/or Pressure Drop Limits: The maximum allowable velocity and/or pressure drop along the pipes in the system will not be exceeded based on the calculated Flow Rate .

    • Set in the Methods and the Systems .

  • Enabled Pipe Sizes: Systems settings control which sizes are available, restricting or enabling diameters based on project requirements.

    • Confirm that the appropriate pipe sizes are enabled/available in Systems Settings.

  • Overridden: The pipe Diameter or the pipes Maximum Velocity/Pressure Drop setting can be Overridden in it’s Properties.

    • If any segment of pipe looks high, it is likely due to this.

Troubleshooting of Pipe Diameter (ø):

Step

Description

Review the Flow Rate

Refer to the Flow Rate section if you want to modify the flow rate.

Review Pressure Drop and Velocity Limits

Consider modifying these to change Pipe Size. Increase limits to decrease pipe size and vice versa.

Sizing Methods

Set different Methods based on Riser, Mains, or Branches. Ensure correct pipe type and system update.

Verify Enabled Pipe Sizes

Confirm appropriate sizes in System Settings; internal diameter is used for sizing, not nominal.

Analyze the Design Report

Export and review Pipe-related parameters like Flow Rates, Velocities, and Pressure Drops.

Use Heat Maps

Visualize high Pressure Drop or Velocity areas to find problematic segments.

Internal Diameter (ID)

The Internal Diameter (ID) is the interior measurement of the pipe and is directly tied to the Pipe Diameter result. It determines the flow capacity and resistance within the system.

Influences of Internal Diameter (ID):

  • Pipe Diameter: The internal diameter is calculated based on the selected nominal diameter.

  • Pipe Material: Different materials may have slight variations in internal diameter, which are defined in the Catalog.

Troubleshooting of Internal Diameter (ID):

Task

Description

Check the Pipe Diameter

Refer to the Pipe Diameter result section to address issues like Flow Rate, Pressure Drop, or Velocity.

Verify the Catalog Data

Ensure the Internal Diameter matches the selected Pipe Material and Size.

System Selection

Confirm the correct Material is selected in the Systems Settings.

Duct Sizing

The duct size is determined based on the design conditions and is selected to ensure optimal airflow, efficiency, and pressure control.

Influences of Duct Sizing:

  • Flow Rate

    • The Duct Size is determined based on the calculated Airflow requirements.

  • Maximum Velocity and/or Pressure Drop Limits

    • The maximum allowable Velocity and/or Pressure Drop along the Ducts in the system will not be exceeded based on the calculated Flow Rate.

    • These settings are configured in the Methods and Systems tabs.

  • Overrides

    • Duct size or Maximum Velocity/Pressure Drop settings can be Overridden in the Properties tab.

    • If a Duct Size looks unusual, it may be due to an Override in its Settings.

Troubleshooting of Duct Sizing:

Action

Description

Review the Flow Rate

Check the Flow Rate section to ensure values align with system requirements. Adjust if needed to influence Duct Size.

Review Pressure Drop and Velocity Limits

Modify these limits for desired Duct Size: increase limits to decrease duct size, decrease limits to increase duct size.

Configure Sizing Methods

Set separate Sizing Methods for system settings Mains, Branches, or Risers.

Ensure Correct System Assignment

Ensure the Duct is assigned to the correct System and matches the intended Type.

Analyze the Design Report

Export the Design Report Spreadsheet to review parameters like Flow Rates, Velocities, and Pressure Drops. Look for discrepancies.

Use Heat Maps

Visualize high-Pressure Drop or Velocity areas to identify problematic segments.

Check for Overrides

Inspect the Properties tab for any Overridden sizes or limits. Correct if they conflict with design parameters.

Cross-Sectional Area

The cross-sectional area refers to the internal area of a Duct and is directly tied to its dimensions. 

Influences of Cross-Sectional Area:

  • Duct Dimensions

    • The area is calculated based on the selected duct dimensions:

      • For rectangular ducts: width × height.

      • For circular ducts, the internal diameter area is calculated.

Troubleshooting of Cross-Sectional Area:

  • Check Duct dimensions

    • Review the Duct dimensions in the Properties tab to ensure they match the design requirements.

    • For Rectangular Ducts, confirm both width and height are accurate.

  • Verify shape selection

    • Ensure the correct Duct shape (Rectangular or Circular) is selected for each segment.

    • Check for high aspect ratios in Rectangular Ducts, which may increase resistance.

  • Analyze Design Report

    • Export the Design Report spreadsheet to check area values for each duct segment.

    • Look for discrepancies or unexpected values, such as insufficient area for required Airflow.

  • Use Heat Maps

    • Visualize areas of high Velocity or Pressure Drop that may indicate issues with the cross-sectional area.

  • Redraw segments if necessary

    • If discrepancies persist, delete and redraw affected duct segments to recalculate the area based on updated dimensions or design inputs.

Pipe/Duct Material

The Pipe/Duct Material refers to the type of material used for the pipe/duct (e.g., Copper, Steel, PVC), which directly affects flow resistance, heat retention, and pressure tolerance.

Influences of the Pipe/Duct Material:

  • System Settings: Materials for Risers, Mains, and Branches are defined here.

  • Properties Overrides: The Material can be Overridden in the Properties tab for specific segments.

Troubleshooting of the Pipe/Duct Material:

Step-by-step

  1. Verify System Settings
    - Ensure the correct Materials are assigned to the Risers, Mains, and Branches in System Settings.

  2. Check the Properties
    - Inspect the Pipe/Duct's Properties to confirm the material matches your design requirements.

  3. Inspect the drawing
    - Confirm that Pipes/Ducts are drawn with the correct Material type.
    - If inconsistencies are found, update the associated System in the properties or redraw the segment with the correct material.

Pressure Drop (PD)

The Pressure Drop refers to the total Pressure Loss across a Pipe/Duct segment caused by friction as Fluid moves through the Pipe/Duct.

Pressure Drop Formula:

ΔP = f × (L / D) × (ρ × v²) / 2

Where:

  • ΔP = Pressure drop (Pa or psi)

  • f = Friction factor (dimensionless, depends on pipe roughness & Reynolds number)

  • L = Length of the pipe (m or ft)

  • D = Internal diameter of the pipe (m or ft)

  • ρ = Fluid density (kg/m³ or lb/ft³)

  • v = Fluid velocity (m/s or ft/s)

Influences of Pressure Drop:

Flow Rate and Velocity

  • Higher Flow Rates and Velocities increase friction, resulting in greater Pressure Drops.

  • Managed by adjusting Flow Rates or selecting a larger Pipe/Duct diameter.

Pipe/Duct Diameter

  • Smaller Pipe/Duct diameters create more resistance and increase Pressure Drop.

  • Larger diameters help reduce Pressure Drop.

Roughness Coefficient

  • The Material roughness impacts friction:

    • Rougher materials (e.g., Steel) have higher friction coefficients and cause greater Pressure Drops.

Equation

  • Calculated using the Darcy-Weisbach equation with the Colebrook-White coefficient.

    • Factors include Flow Rate, Pipe/Duct diameter, material roughness, and Fluid density.

Troubleshooting of Pressure Drop:

Task

Steps

Check Flow Rate

Review the Flow Rates in the system to ensure they are correct.

Check Settings

Review the Maximum Velocity and Pressure Drop settings in the Methods and Systems. Adjust these settings to align with system requirements.

Inspect Pipe/Duct Diameter

Verify that the Pipe/Duct diameters match the design requirements. Smaller diameters increase Pressure Drop; consider selecting larger pipes/ducts for affected segments.

Review Pipe/Duct Material and Roughness Coefficient

Confirm the Material for each Pipe/Duct segment; rougher Materials (e.g., Steel) may cause higher friction. If necessary, replace with smoother Materials (e.g., PVC) to reduce resistance.

Analyze the Design Report

Export the Design Report Spreadsheet to check Pressure Drop values for each segment. Look for anomalies or areas where pressure drop exceeds design limits.

Use Heat Maps

Visualize areas of high-Pressure Drop within the system to identify problematic segments. There may be areas where the maximum limits have been Overridden. If you find areas with high-pressure drops and are unsure why, delete and redraw the affected Pipe/Duct segments. Ensure the correct diameter, material, and connections are used.

Verify Connections

Ensure all Pipe/Duct connections, Fittings, and Valves are accurately defined and appropriately sized to minimize resistance.

Length

The Length refers to the measured distance of a Pipe or Duct segment, which is critical for determining Pressure Drop, Velocity, and overall system performance.

Influences of Length:

1. Drawing Scale

  • Length is automatically calculated based on the Scale of the Drawing.

  • If the Drawing is not to Scale, the Computed Length may be inaccurate, leading to incorrect Pressure Drop and Velocity values.

2. Manual Overrides

  • Length can be Overridden manually in the segment’s Properties tab.

  • Overrides should only be used when the drawn length does not accurately represent the actual system length (e.g., for hidden segments or prefabricated components).

Troubleshooting of the Pipes/Ducts Length:

Step-by-step

  1. Verify the Drawing Scale

    - Check that the Drawing is set to the correct Scale.
    - Use the Scale Drawing Tool to confirm or adjust the Scale for accuracy.

  2. Inspect Length Overrides
    - Review the Properties tab for each segment to see if the Length has been manually Overridden.
    - If Overridden, ensure the manual value matches the actual Length of the Pipe or Duct.

  3. Use Heat Maps and Design Reports
    - Heat Maps: Visualize discrepancies in Length-related parameters, such as Pressure Drop or Velocity.
    - Design Reports: Export the Design Report Spreadsheet and verify the Lengths of all segments for anomalies.

  4. Redraw Affected Segments
    - If Lengths appear incorrect, delete and redraw the affected segments to recalculate the Length based on the updated Scale or geometry.

Pressure Drop Rate

The Pressure Drop Rate is the Pressure Loss per Unit Length of a Pipe Segment.

Influences of the Pressure Drop Rate:

  • Pressure Drop

    • The Pressure Drop across a segment.

  • Pipe/Duct Length

    • The Length of the segment.

Troubleshooting of the Pressure Drop Rate:

Step

Description

Check Total Pressure Drop

Review the total Pressure Drop for each segment to identify areas with excessive values.

Inspect Pipe/Duct Lengths

Review the Length result filters. If the length looks unusual, it may have been Overridden in the Properties.