Feature Request: Fan speed

Hello,
When printing with filaments that don't require a heated chamber it would be nice to slow down the fan in order to make the printer quieter for printing. I understand that heating would require full speed in order to push the hot air from the device but an option to lower noise when not heating the chamber would be nice.

The issue names no files or tests. Start by locating the fan-speed control and chamber-heating entry points, then trace how printing state selects fan behavior. Done means fan speed can be reduced for prints without chamber heating while heating still uses full speed, with the behavior verified on the printer.

Written by the indexing model from the issue text.