Cross-platform fan control for Linux, Windows, and macOS - modern, minimal, open source.

LinFan reads temperature sensors and fans, calibrates them automatically on first start, and drives fan speed with freely definable curves (temperature → power). A privileged daemon runs the control loop with a fail-safe watchdog; the GUI runs without root and talks to it over local IPC.

More screenshots - curve editor and settings

Features

• Read fans (RPM) and temperature sensors, live in the dashboard.
• Auto-calibration on first start: ramps each PWM channel 0→100 %, detects which channels actually drive a fan, the start-up/stall point, and the PWM→RPM characteristic.
• Curve editor as a graph: temperature → power, draggable points, hysteresis, smoothing against short temperature spikes, live operating point. A curve can be assigned to one or more fans.
• Airflow auto-tune: derives a pressure balance and role curves (CPU, GPU, intake, exhaust) from the fans' mounting positions.
• Profiles (e.g. silent / performance) with their own curves, switchable from the dashboard.
• Manual mode per fan (slider), rename fans/sensors, maintain install position.
• Fail-safe: over-temperature, a crash, or shutdown → fans to hardware auto / 100 %.

Quick start

Install a release

Grab the asset for your platform from the releases page:

# Debian/Ubuntu
sudo apt install ./linfan_<version>_amd64.deb

# any other distro - self-extracting installer (elevates itself, no sudo needed):
chmod +x LinFan-Setup-<version>-linux-x64.run && ./LinFan-Setup-<version>-linux-x64.run

# or: unpack the tarball and run the same installer script
tar xzf linfan-<version>-linux-x64.tar.gz && ./packaging/linux/install-bin.sh

On Windows, run LinFan-Setup-<version>-win-x64.exe (or unpack the ZIP and run Install-LinFan.ps1 as admin). Every route sets up the service plus the IPC access group (linfan on Linux, LinFan Users on Windows) - log out and back in once, then start "LinFan". Details - privileges, service, uninstall - in docs/INSTALL.md.

Build from source

dotnet build                                     # build everything
dotnet test                                      # test suite

dotnet run --project src/LinFan.Daemon -- list   # list sensors & fans
dotnet run --project src/LinFan.Daemon -- run    # control loop + IPC server (dry run without root)
dotnet run --project src/LinFan.App              # GUI (no root) - connects to a running daemon

Writing PWM for real requires root/admin (on Linux possibly a driver flag such as thinkpad_acpi fan_control=1); in normal operation the daemon runs as a systemd/Windows service. The full guide - privileges, service installation, Windows, and the manual macOS start - is in docs/INSTALL.md.

Documentation

• docs/INSTALL.md - installation & operation (Linux, Windows, macOS), privileges, service.
• docs/ARCHITECTURE.md - MVC layers, IPC contract, fail-safe, data model.
• docs/HARDWARE.md - platform-specific hardware access, calibration, dependencies.
• CHANGELOG.md - release history.

Tech stack

Area	Choice
Language / runtime	C# / .NET 8 (LTS)
GUI	Avalonia UI 12 (Fluent theme)
Controller	CommunityToolkit.Mvvm
Hardware Linux	direct sysfs/hwmon access
Hardware Windows	LibreHardwareMonitorLib (MPL-2.0)
Persistence	System.Text.Json
Service / logging	Microsoft.Extensions.Hosting, Serilog

The platform-specific hardware access (the core of the project) and the full dependency list are in docs/HARDWARE.md.

Known issues

• macOS: Intel Macs are untested (same code path, validated only on an M2 Pro), there is no launchd service yet (start the daemon manually), and temperature sensors come from a curated key list, so some may be missing - open an issue with your model and the monitor output.
• Group membership needs a re-login (Linux and Windows). Until you log out and back in, the GUI reports the daemon as unreachable although it is running.
• Some sensor channels report intermittent read errors (e.g. ThinkPad EC, EIO) - they show as a missing value; the control loop and the watchdog keep running.
• The Windows binaries/installer are unsigned - SmartScreen warns on first run (More info → Run anyway); verify the download against SHA256SUMS.txt on the release page, see docs/INSTALL.md.

Contributing

Issues and pull requests are welcome - CONTRIBUTING has the setup, quality gates, and conventions. Before a PR, please keep dotnet build, dotnet test and dotnet format green. For vulnerabilities, please follow the security policy instead of opening a public issue.

License

GNU General Public License v3.0 or later (GPL-3.0-or-later) - full text in LICENSE. Copyright © 2026 Patrick Machynia. Distributed without any warranty. The dependencies are GPLv3-compatible (Avalonia, CommunityToolkit.Mvvm: MIT; LibreHardwareMonitorLib: MPL-2.0).