diff --git a/main/fancontrol.c b/main/fancontrol.c
index 06b6cdb..365b070 100644
--- a/main/fancontrol.c
+++ b/main/fancontrol.c
@@ -8,9 +8,11 @@
 #include "settings.h"
 #include "actuators.h"
 
+#define UNIDIR_T_MEAS_PERIOD 15 /* s */
 struct FanControlState gState = {};
 
 static void timerCallback(TimerHandle_t xTimer);
+static void invalidate_temps();
 
 void settings_blind_time_set(uint16_t blind_time) {
     bool nadoraz = (gState.blind_position >= gSettings.blind_time) || (gState.blind_position >= blind_time);
@@ -25,7 +27,7 @@ void settings_blind_time_set(uint16_t blind_time) {
 }
 
 void fancontrol_init() {
-    gState.vent_mode = gSettings.initial_mode;
+    gState.set_vent_mode = gSettings.initial_mode;
     gState.set_power = gSettings.initial_power;
 
     xTimerCreate("fanctl",
@@ -69,7 +71,9 @@ static void timerCallback(TimerHandle_t xTimer) {
         }
     }
 
-    switch (gState.vent_mode) {
+    bool end_temp_meas = false;
+
+    switch (gState.effective_vent_mode) {
         case VENT_MODE_OFF:
             act_motor_power_set(0);
             act_blind_set(0);
@@ -84,6 +88,9 @@ static void timerCallback(TimerHandle_t xTimer) {
             if (gState.blind_position >= gSettings.blind_time) {
                 act_motor_power_set(gState.set_power);
             }
+            if (gState.t_aggr_cnt > UNIDIR_T_MEAS_PERIOD) {
+                end_temp_meas = true;
+            }
             break;
         case VENT_MODE_IN:
             act_motor_direction_set(MOTOR_DIR_IN);
@@ -91,6 +98,9 @@ static void timerCallback(TimerHandle_t xTimer) {
             if (gState.blind_position >= gSettings.blind_time) {
                 act_motor_power_set(gState.set_power);
             }
+            if (gState.t_aggr_cnt > UNIDIR_T_MEAS_PERIOD) {
+                end_temp_meas = true;
+            }
             break;
         case VENT_MODE_RECUP:
             act_blind_set(1);
@@ -103,6 +113,7 @@ static void timerCallback(TimerHandle_t xTimer) {
                         // zmena smeru
                         gState.run_time = 0;
                         act_motor_direction_set(1 - gAct.dir);
+                        end_temp_meas = true;
                     }
                 }
             }
@@ -110,23 +121,94 @@ static void timerCallback(TimerHandle_t xTimer) {
             break;
     }
 
-    if (gAct.dir == gState.real_direction && gState.ramp >= gSettings.ramp_time) {
-        // Measure temperatures
-        int16_t t1 = 200;
-        int16_t t2 = 200; // TODO
-
-        gState.t_actual_1 = t1;
-        gState.t_actual_2 = t2;
+    if (gState.effective_vent_mode == VENT_MODE_RECUP) {
+        if (gState.real_direction == MOTOR_DIR_OUT) {
+            gState.instantaneous_vent_mode = VENT_MODE_OUT;
+        } else {
+            gState.instantaneous_vent_mode = VENT_MODE_IN;
+        }
+    } else {
+        gState.instantaneous_vent_mode = gState.effective_vent_mode;
+    }
 
+    if (end_temp_meas) {
+        uint16_t t1 = (uint16_t) (gState.t1_aggr / gState.t_aggr_cnt);
+        uint16_t t2 = (uint16_t) (gState.t2_aggr / gState.t_aggr_cnt);
         switch (gState.real_direction) {
             case MOTOR_DIR_IN:
                 gState.t_outdoor = t2;
                 gState.t_intake = t1;
+                gState.valid_t_outdoor = gState.valid_t_intake = true;
+                if (gState.effective_vent_mode == VENT_MODE_IN) {
+                    gState.valid_t_indoor = gState.valid_t_exhaust = false;
+                }
                 break;
             case MOTOR_DIR_OUT:
                 gState.t_indoor = t1;
                 gState.t_exhaust = t2;
+                gState.valid_t_indoor = gState.valid_t_exhaust = true;
+                if (gState.effective_vent_mode == VENT_MODE_OUT) {
+                    gState.valid_t_outdoor = gState.valid_t_intake = false;
+                }
                 break;
         }
+        gState.t1_aggr = gState.t2_aggr = gState.t_aggr_cnt = 0;
+    }
+
+    if (gState.effective_vent_mode == VENT_MODE_IN
+        || gState.effective_vent_mode == VENT_MODE_OUT
+        || gState.effective_vent_mode == VENT_MODE_RECUP) {
+        // Measure temperatures
+        int16_t t1 = 200;
+        int16_t t2 = 190; // TODO
+
+        gState.t_actual_1 = t1;
+        gState.t_actual_2 = t2;
+
+        gState.valid_t_actual_1 = gState.valid_t_actual_2 = true;
+
+        if (gAct.dir == gState.real_direction
+            && gState.ramp >= gSettings.ramp_time) {
+            gState.t1_aggr += t1;
+            gState.t2_aggr += t2;
+            gState.t_aggr_cnt++;
+        }
+    } else {
+        gState.valid_t_actual_1 = gState.valid_t_actual_2 = false;
+    }
+}
+
+void fan_set_vent_mode(enum ventilation_mode mode) {
+    if (mode == gState.set_vent_mode) {
+        return;
+    }
+
+    gState.set_vent_mode = mode;
+    gState.t1_aggr = gState.t2_aggr = gState.t_aggr_cnt = 0;
+    if (gState.set_power != 0) {
+        gState.effective_vent_mode = mode;
+    }
+
+    if (mode == VENT_MODE_OFF || mode == VENT_MODE_FREE) {
+        invalidate_temps();
     }
 }
+
+static void invalidate_temps() {
+    gState.valid_t_indoor = false;
+    gState.valid_t_outdoor = false;
+    gState.valid_t_intake = false;
+    gState.valid_t_exhaust = false;
+    gState.valid_t_actual_1 = false;
+    gState.valid_t_actual_2 = false;
+}
+
+void fan_set_power(uint16_t power) {
+    gState.set_power = power;
+    if (power == 0) {
+        gState.effective_vent_mode = VENT_MODE_OFF;
+        invalidate_temps();
+    } else {
+        gState.effective_vent_mode = gState.set_vent_mode;
+    }
+}
\ No newline at end of file
diff --git a/main/fancontrol.h b/main/fancontrol.h
index c3b6dc1..32bce03 100644
--- a/main/fancontrol.h
+++ b/main/fancontrol.h
@@ -20,30 +20,24 @@ enum ventilation_mode {
 
 struct FanControlState {
     /**
-     * Poloha roletky, 0<->blind_time, inkrement/dekrement 1 za sekundu.
-     * Pri zmene blind_time se musi hodnota aktualizovat, pokud je na doraze nebo za.
-     */
-    uint16_t blind_position;
-    /**
-     * Power requested trough register or as the default value
+     * Power requested trough register or as the default value.
+     * This value stays unchanged even if stopped, unlike gAct.power which reflects the actual output.
      */
     uint16_t set_power;
     /**
-     * Cas chodu motoru v aktualnim smeru, inkrement 1 za sekundu.
-     */
-    uint16_t run_time;
-    /**
-     * "stav chodu motoru". 0=stop, ramp_time = jede.
-     */
-    uint16_t ramp;
-    /**
-     * skutecny aktualni pohyb motoru (zustava stejny, dokud ramp time nedosahne nuly)
-     */
-    enum motor_direction real_direction;
-    /**
-     * rezim ventilace
+     * rezim ventilace. Use fan_set_vent_mode() to change it!
      */
-    enum ventilation_mode vent_mode;
+    enum ventilation_mode set_vent_mode;
+    /** Status for the register */
+    enum ventilation_mode instantaneous_vent_mode;
+
+    /* sensors */
+    bool valid_t_indoor;
+    bool valid_t_outdoor;
+    bool valid_t_intake;
+    bool valid_t_exhaust;
+    bool valid_t_actual_1;
+    bool valid_t_actual_2;
 
     uint16_t t_indoor;
     uint16_t t_outdoor;
@@ -52,8 +46,37 @@ struct FanControlState {
 
     uint16_t t_actual_1;
     uint16_t t_actual_2;
+
+    // Private
+    /**
+     * like vent_mode, but if power is 0, becomes OFF
+     */
+    enum ventilation_mode effective_vent_mode;
+    /**
+     * skutecny aktualni pohyb motoru (zustava stejny, dokud ramp time nedosahne nuly)
+     */
+    enum motor_direction real_direction;
+    /**
+     * Poloha roletky, 0<->blind_time, inkrement/dekrement 1 za sekundu.
+     * Pri zmene blind_time se musi hodnota aktualizovat, pokud je na doraze nebo za.
+     */
+    uint16_t blind_position;
+    /**
+     * Cas chodu motoru v aktualnim smeru, inkrement 1 za sekundu.
+     */
+    uint16_t run_time;
+    /**
+     * "stav chodu motoru". 0=stop, ramp_time = jede.
+     */
+    uint16_t ramp;
+    uint32_t t1_aggr;
+    uint32_t t2_aggr;
+    uint32_t t_aggr_cnt;
 };
 
 extern struct FanControlState gState;
 
+void fan_set_vent_mode(enum ventilation_mode mode);
+void fan_set_power(uint16_t power);
+
 #endif //FANCTL_FANCONTROL_H