diff --git a/machines/fuuko/configuration.nix b/machines/fuuko/configuration.nix
index 3402be5..0b0d78f 100644
--- a/machines/fuuko/configuration.nix
+++ b/machines/fuuko/configuration.nix
@@ -8,6 +8,7 @@
     ./services/media-backup.nix
     ./services/media.nix
     ./services/torrent.nix
+    ./services/co2_exporter.nix
   ];
 
   sbruder = {
diff --git a/machines/fuuko/services/co2_exporter.nix b/machines/fuuko/services/co2_exporter.nix
new file mode 100644
index 0000000..e0a4e51
--- /dev/null
+++ b/machines/fuuko/services/co2_exporter.nix
@@ -0,0 +1,8 @@
+{ config, ... }:
+
+{
+  services.co2_exporter = {
+    enable = true;
+    listenAddress = "${config.sbruder.wireguard.home.address}:9672"; # uses port numer of unrelated co2 exporter to avoid 8080
+  };
+}
diff --git a/machines/renge/services/prometheus.nix b/machines/renge/services/prometheus.nix
index d3479c4..9a36bde 100644
--- a/machines/renge/services/prometheus.nix
+++ b/machines/renge/services/prometheus.nix
@@ -98,6 +98,10 @@ in
         job_name = "hcloud";
         static_configs = mkStaticTarget config.services.hcloud_exporter.listenAddress;
       }
+      {
+        job_name = "co2";
+        static_configs = mkStaticTarget "fuuko.vpn.sbruder.de:9672";
+      }
     ];
 
     rules =
diff --git a/modules/udev.nix b/modules/udev.nix
index c57ac10..36e8a14 100644
--- a/modules/udev.nix
+++ b/modules/udev.nix
@@ -15,6 +15,9 @@
 
     # TI-84+ SE
     SUBSYSTEM=="usb", ATTRS{idVendor}=="0451", ATTRS{idProduct}=="e008", MODE="0660", GROUP="users"
+
+    # TFA AIRCO2NTROL COACH (Holtek Semiconductor, Inc. USB-zyTemp)
+    SUBSYSTEMS=="usb", ATTRS{idVendor}=="04d9", ATTRS{idProduct}=="a052", MODE="0644"
   '';
 
   boot.kernelModules = [ "uinput" ];
diff --git a/pkgs/co2_exporter/default.nix b/pkgs/co2_exporter/default.nix
new file mode 100644
index 0000000..8ae215b
--- /dev/null
+++ b/pkgs/co2_exporter/default.nix
@@ -0,0 +1,24 @@
+{ lib, buildGoModule, fetchFromGitHub }:
+
+buildGoModule rec {
+  pname = "co2_exporter";
+  version = "unstable-2022-11-03";
+
+  src = fetchFromGitHub {
+    owner = "sbruder"; # fork of am3o’s original version
+    repo = pname;
+    rev = "49ee376d257c0d92dcb819de6d67bb16d64b0339";
+    sha256 = "sha256-GJyIS6G0egSfk6LI38VqXg+E+WWQqJRmcvUU9Nk5MSo=";
+  };
+
+  subPackages = [ "." ];
+
+  vendorSha256 = "sha256-CMo6FBzw0/OMKEX12oNqhbF/0dRRFR6W3VRp+EU6Q68=";
+
+  oCheck = false; # no tests
+
+  meta = with lib; {
+    license = licenses.mit;
+    maintainer = with mainatiners; [ sbruder ];
+  };
+}
diff --git a/pkgs/co2_exporter/module.nix b/pkgs/co2_exporter/module.nix
new file mode 100644
index 0000000..a01312b
--- /dev/null
+++ b/pkgs/co2_exporter/module.nix
@@ -0,0 +1,45 @@
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.services.co2_exporter;
+in
+{
+  options.services.co2_exporter = {
+    enable = lib.mkEnableOption "co2 exporter";
+    package = lib.mkOption {
+      type = lib.types.package;
+      default = pkgs.co2_exporter;
+      description = "The package to use for the exporter.";
+    };
+    device = lib.mkOption {
+      type = lib.types.nullOr lib.types.path;
+      default = null;
+      description = "The path to the co2 monitor device.";
+    };
+    listenAddress = lib.mkOption {
+      type = lib.types.str;
+      default = ":8080";
+      description = "The address to listen on";
+      example = "127.0.0.1:8080";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.co2_exporter = {
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+      environment = {
+        CO2MONITOR_ADDRESS = cfg.listenAddress;
+      } // (lib.optionalAttrs (!isNull cfg.device) {
+        CO2MONITOR_DEVICE = cfg.device;
+      });
+      serviceConfig = {
+        ExecStart = "${cfg.package}/bin/co2_exporter";
+        Restart = "always";
+
+        # systemd-analyze --no-pager security co2_exporter.service
+        DynamicUser = true;
+        # FIXME
+      };
+    };
+  };
+}
diff --git a/pkgs/default.nix b/pkgs/default.nix
index 5073cda..d6f2bab 100644
--- a/pkgs/default.nix
+++ b/pkgs/default.nix
@@ -5,6 +5,8 @@ in
 {
   bwrap-helper = callPackage ./bwrap-helper { };
 
+  co2_exporter = callPackage ./co2_exporter { };
+
   osu-lazer = callPackage ./osu-lazer { inherit (prev) osu-lazer; };
   osu-lazer-sandbox = callPackage ./osu-lazer-sandbox { };
 
diff --git a/pkgs/modules.nix b/pkgs/modules.nix
index eb93ec3..f1c0eca 100644
--- a/pkgs/modules.nix
+++ b/pkgs/modules.nix
@@ -3,5 +3,6 @@
 {
   imports = [
     ./wordclock-dimmer/module.nix
+    ./co2_exporter/module.nix
   ];
 }