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🖋️ System Design

Valves

Valves are used to control, regulate, or isolate flow.

Some Valves are key to calculations (e.g., Balancing Valves), but most, like Strainers, contribute only to pressure drop.

How Valves Work

Valves are designed to connect to pipes/ducts. Here's how you can add them:

A color change (from gray to colored) confirms a proper connection.

  • Placement:

    • Valves can be added before or after drawing the Pipe/Duct Layout.

    • When adding them before drawing Pipes/Ducts, place the valve at the desired location, then connect pipes to its inlets and outlets.

    • If adding valves to an existing layout, they snap directly onto the Pipe/Duct.

  • Connection Indication:

    • A proper connection is visually confirmed when the valve changes from gray (unconnected) to a colored state (connected).

    • This color change ensures the valve is correctly aligned with the pipe and will function as part of the system.

  • Versatility in Placement:

    • Valves can be added anywhere in the system, including along straight runs, at branches, fittings, or near Equipment.

      1. We don’t yet have the functionality to add valves to vertical segments of Pipe/Duct like Risers.

  • Adjustable Settings:

    • Once placed, valves inherit default Properties from the System Settings but can be customized in the properties panel.

      • For example, pressure settings, flow direction, or open/close states can be modified to suit specific design needs.

  • Integration with System Calculations:

    • Properly connected valves contribute to calculations such as pressure drop, flow rate adjustments, and balancing.

    • Misconnections or missing valves may result in calculation errors or Warnings.

Types of Valves for Water Systems (Domestic Water, Fire, Hydronic Heating/Chilled)

Isolation Valves

Used to shut off flow to specific sections, enabling maintenance without disrupting the entire system.

  • Gate Valve: commonly used where it will mostly remain fully open or closed for long periods

  • Ball Valve: commonly used on small systems where fast operation required

  • Butterfly Valve: commonly used on larger systems

Balancing Valves

Essential for recirculating systems (e.g., Hot Water, Heating, Chilled) to ensure even distribution of flow and pressure.

  • Balancing Valve: commonly used on hot water systems

  • PICV (Pressure Independent Control Valve): commonly used on chilled water systems

  • Lockshield Valve: commonly used on heating systems

Mixing Valves

Mix hot and cold water to ensure safe output temperatures, especially in domestic hot water systems.

  • Thermostatic Mixing Valve (TMV): commonly used on healthcare, schools and aged care systems) due to fail safe benefits

  • Tempering Valve: commonly used on residential and office systems

Backflow Prevention Valves

Prevent fluid from flowing in the wrong direction, avoiding contamination.

  • Check Valve: simple one-way valve

  • RPZ Valve (Reduced Pressure Zone): prevents backflow in higher-risk scenarios

  • Double RPZ Valve: can handle 50% or 100% of peak flow, depending on redundancy needs

Other Water Valves

  • Meter: Tracks water flow and adds a pressure drop

  • Temperature Control Valve (TVC): Regulates system temperature and adds pressure drop

  • Commissioning Valve: Used during system setup; adds pressure drop

  • Strainer: Filters debris from water; adds pressure drop

  • Diverter (2-Port, 3-Port) Valve: Sizes the inlet pipe to the largest of the two upstream outlets, typically in heating systems to prioritise loads between space heating and domestic hot water generation 

  • Pressure Relief Valve: Relieves excess pressure caused by temperature changes; adds pressure drop

  • Pressure Reducing Valve: Steps down pressure in systems to avoid excessive force on fixtures; enter the maximum pressure outlet in the properties.

Custom Valve

The custom valve is a component for scenarios where h2x’s default valve types don’t meet your specific design requirements. 

Users can define its Name, assign a K Value, or input a fixed pressure drop directly in the Properties.

Types of Valves for Ventilation Ductwork Systems

Attenuator

Reduces noise and vibration in ventilation systems while maintaining airflow.

Includes a zeta coefficient in its Properties, which can be adjusted to reflect its pressure drop.

Smoke Damper

Prevents the spread of smoke through the ventilation system during a fire.

Includes a zeta coefficient in its Properties to account for pressure drop in the system.

Fire Damper

Stops the spread of fire through ducts by sealing off airflow in affected areas.

Has a zeta coefficient in its Properties to include the associated pressure drop in calculations.

Balancing Damper

Equalizes airflow throughout the system, ensuring even distribution to all outlets.

Often placed on branches serving individual Diffusers or Grilles.

Pressure drop is calculated to ensure the pressure at all diffusers/grilles is equal.

The index path will have the smallest pressure drop, and the ones nearest to the air handling unit will have the highest to account for the lack of pressure drop along the ducts and fittings to it.

Variable Control Damper (VCD)

Regulates airflow by adjusting the damper position to control volume.

Typically sized for the peak flow rate specified in the system.

Has a zeta coefficient in its Properties to include the associated pressure drop in calculations.

Fan

A critical component in a Fan Exhaust system, responsible for expelling air.

The Fan is sized to handle the maximum flow rate specified for the system.

Designed to overcome the total pressure drop along the index path.

Ensure the arrow on the fan is facing in the direction of flow. You can change this in the Properties tab.

Types of Valves for Gas Systems

Gas Regulator

Define the gas pressure downstream in the system.

Users can input the Outlet Pressure, which is the pressure immediately downstream of the Regulator.

Additionally, users can specify the Target Pressure for all appliances connected downstream. 

These settings can be overridden for specific appliances as needed.

Gas Meter

Measures and regulates the gas flow in a system.

The gas meter has a pressure drop field in its Properties, which can be adjusted based on the type of meter and its specifications.

Gas Filter

Removes impurities and debris from the gas supply to protect downstream equipment.

The gas filter has a pressure drop field in its Properties, which can be manually adjusted if needed.

Gas Isolation Valve

Shuts off the gas supply to specific sections of the system for maintenance or emergencies.

The isolation valve can be toggled to Closed in its properties to stop the flow of gas.

It has an effective length associated with it, contributing to pressure drop calculations within the system.

Types of Valves for Drainage Systems

Floor Waste

Acts as a gully for collecting and draining spilled or excess water from floors, ensuring proper drainage in wet areas.

No impact on the calculations. 

Inspection Opening

Provides access to the drainage system for maintenance and clearing blockages. It ensures a properly functioning drainage system.

No impact on the calculations. 

Reflux Valve

Allows water to flow in only one direction, preventing backflow and protecting against flooding or contamination in the drainage system.

No impact on the calculations. 

Troubleshooting Valves

  • Connection Issues: Ensure Valves snap to Pipes/Ducts; if semi-transparent, they are not properly connected.

  • Pressure Drop: Review pressure drop values in Properties and ensure they align with system design.

  • Flow Direction: Confirm flow direction settings in Properties, especially for backflow prevention valves.

  • Balancing Errors: Verify Balancing Valves are correctly placed for recirculating systems.

    • If the flow and return colors aren't showing, you have likely connected an emitter the wrong way around (e.g. connected the flow to the return, and vice versa), or misplaced a Balancing Valve