> 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.-7-four-pipe-fan-coil.md). # System No. 7 Four-pipe Fan-coil A Four-Pipe Fan Coil system, as defined in EnergyPlus HVACTemplate, is a climate control system commonly used in hotels, apartments, office buildings, and other multi-zone applications. It consists of individual fan coil units installed in each zone, connected to two separate hydronic loops: one circulating chilled water for cooling and another circulating hot water for heating. Each fan coil unit contains two independent coils, one for chilled water and one for hot water, along with a fan that distributes the conditioned air throughout the space. Unlike two-pipe systems, the four-pipe configuration allows simultaneous heating and cooling availability in all zones year-round, providing maximum flexibility and comfort. The system ensures individual zone temperature control, the ability to meet diverse thermal loads simultaneously, and relatively quiet operation. This configuration is particularly suitable for applications where decentralized zone control with simultaneous heating and cooling capability is preferred. A Four-Pipe Fan Coil system comprises one Plant HVAC component and multiple Space HVAC components (per selected Space). * Plant HVAC component - Four-Pipe Hydronic System (Chilled Water and Hot Water) * Space HVAC component - Four-Pipe Fan Coil Unit 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 Four-Pipe Fan Coil Unit Space HVAC component, providing individual zone climate control. --- # 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://docs.betterbuilding.io/user-guide/2d-building/building/hvac/hvac-templates/system-no.-7-four-pipe-fan-coil.md?ask=&goal= ``` `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.