> 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/space-hvac/air-terminal/heating-coil.md). # Heating Coil A heating coil is a component used for space heating in HVAC systems. For electric heating, the heating coil is typically an electric resistance coil that converts electrical energy into heat. In the case of water heating, the heating coil is a heat exchanger through which hot water flows to transfer thermal energy to the air stream.
## Heating Coil (Electric Heating) ### Sizing Method Specify the sizing method as Autosize or Manual. If Manual is chosen, ensure all sizing parameters are specified. ### Coil Efficiency Specify the coil efficiency as a user-defined efficiency in decimal units (not percent), with a typical value of 100% for electric coils. ### Capacity Specify the maximum capacity of the coil in watts. This controlled coil will provide only the needed capacity to meet the control criteria, whether it is temperature or capacity controlled. ## Heating Coil (Water Heating) ### Sizing Method Specify the sizing method as Autosize or Manual. If Manual is chosen, ensure all sizing parameters are specified. ### Max. Water Flow Rate Specify the maximum water flow rate in m³/s through the coil when the Coil Performance Input Method is set to U Factor Times Area And Design Water Flow Rate. ### Capacity Specify the maximum capacity of the coil in watts. This controlled coil will provide only the needed capacity to meet the control criteria, whether it is temperature or capacity controlled. ### Inlet Air Temp Specify the inlet air temperature in degrees Celsius corresponding to the rated heating capacity. The default value is 16.6 degrees Celsius. ### Inlet Water Temp Specify the inlet water temperature in degrees Celsius corresponding to the rated heating capacity. The default value is 82.2 degrees Celsius. ### Output Air Temp. Specify the output air temperature in degrees Celsius corresponding to the nominal heating capacity. The default value is 32.2 degrees Celsius. ### Output Water Temp. Specify the outlet water temperature in degrees Celsius corresponding to the rated heating capacity. The default value is 71.1 degrees Celsius. ### Ratio for Air and Water Convection Specify the ratio of convective heat transfers between the air side and water side of the heating coil at the rated operating conditions. The default value is 0.5. {% hint style="info" %} Only on Premium Plans. Please reach for further [support](/support-and-training/contact-us.md). {% endhint %} --- # 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/space-hvac/air-terminal/heating-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.