> For the complete documentation index, see [llms.txt](https://help.arkance-systems.com/pressure-drops/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.arkance-systems.com/pressure-drops/en/manual/pressure-drop-calculation.md).

# Pressure Drop Calculation

The Pressure Drops application allows users to fill in the loss coefficients of the individual ductwork components for the selected route. Based on these coefficients and the air flow data through the pipe, which are taken from the HVAC system values, the application calculates the total pressure drop of the selected route. Based on this calculation, the designer can determine the critical route to properly dimension the system.

The calculation of the route pressure drop is very intuitive. The user selects the route on which the pressure drop needs to be calculated. In the main Pressure Drops dialog, the route elements with their properties are displayed. The user assigns the specific loss coefficient for each element along the selected duct route. The pressure drop values for straight and flex ducts are calculated automatically by the application. The application then calculates the total pressure drop value of the selected route, according to which the designer can evaluate the HVAC system. In case of repeated calculation, it is not necessary to enter the values of the specific loss coefficients again, the application saves the entered values for each instance.

<figure><img src="/files/usUvh3QS4baSOp8rkSlG" alt=""><figcaption><p>Pressure Drops main dialog with dcut route pressure drop calculation</p></figcaption></figure>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://help.arkance-systems.com/pressure-drops/en/manual/pressure-drop-calculation.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.