> For the complete documentation index, see [llms.txt](https://docs.betterbuilding.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.betterbuilding.io/user-guide/2d-building/building/hvac/hvac-templates/system-no.-6-packaged-vav-with-pfp-boxes.md).

# System No. 6 Packaged VAV with PFP Boxes

A Packaged Variable Air Volume (VAV) with Parallel Fan-Powered (PFP) Boxes system, as defined in EnergyPlus HVACTemplate, is a climate control system commonly used in medium to large commercial buildings. It consists of a self-contained packaged unit, typically installed on the roof, that integrates cooling, heating, and air handling components in a single assembly. 

The system uses a direct expansion (DX) cooling coil for primary cooling and supplies variable volumes of conditioned air through ductwork to multiple VAV terminal units serving different zones. Each parallel fan-powered box contains a small fan that operates in parallel with the primary air supply, drawing plenum air and mixing it with the primary air to maintain airflow and provide heating through integrated reheat coils (electric, hot water, or gas). 

The packaged unit draws outdoor air for ventilation, and the combination of central and terminal unit fans distributes conditioned air throughout the building, ensuring effective temperature control, improved air circulation, and individual zone comfort. This configuration is particularly suitable for applications where multi-zone control with enhanced air distribution and energy-efficient VAV operation is preferred.

<figure><img src="/files/HSx2Q8ulBnvGTi8dW78Y" alt=""><figcaption></figcaption></figure>

A Packaged VAV with PFP Boxes system comprises:

* Plant HVAC component - Air Handling Unit&#x20;
* Space HVAC component - Parallel PIU

The 'Select HVAC Template' form allows for multiple Spaces to be served. Clicking into the 'Spaces' field shows a list of available Spaces. Each selected Space will have one VAV Terminal Unit with Parallel Fan-Powered Box Space HVAC component, providing individual zone climate control.


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