diff --git a/projects/shelly_taupunktluefter/AGENTS.md b/projects/shelly_taupunktluefter/AGENTS.md
index c5ce3e9..e119508 100644
--- a/projects/shelly_taupunktluefter/AGENTS.md
+++ b/projects/shelly_taupunktluefter/AGENTS.md
@@ -25,20 +25,20 @@ In warm months, blowing outdoor air into a cool cellar can heat up the cellar ma
 *   **Ceiling Protection**: If $T_{in} \ge 20^\circ\text{C}$, the fan is **only** permitted to run if outdoor air is cooler than inside ($T_{out} \le T_{in}$).
 *   **Warming Allowance**: If $T_{in} < 20^\circ\text{C}$, gentle warming is permitted, but outdoor temperature cannot exceed $20^\circ\text{C}$ ($T_{out} \le 20^\circ\text{C}$).
 
-### 3. Seasonal Target Humidities
-*   **Cold / Winter Mode** ($T_{in} < 14^\circ\text{C}$ or $T_{out} < 10^\circ\text{C}$): Targets **50% RH**. Once 50% RH is reached, the fan stops to preserve cellar warmth.
-*   **Warm / Summer Mode**: Targets **40% RH** for maximum drying.
+### 3. Target Humidities
+*   **Target Humidity**: Set to **55% RH** (with a 2% hysteresis shut-off down to 53% when ventilating). Once 55% RH is reached, the fan rests to preserve cellar warmth and prevent excessive wall moisture desorption.
 *   **Hard Cold Floor**: The fan is blocked if $T_{in} \le \text{mindesttemperatur}$ (default 10°C).
 
 ### 4. 2-Tier Scheduling & Optimal Night Window
-In Central Europe / Germany, the diurnal temperature and absolute humidity minimum occurs in early morning (~03:00–07:00, peak around 05:00):
-*   **Urgent Drying ($RH_{in} > 60\%$)**: Runs 24/7 whenever psychrometric and temperature guards allow.
-*   **Routine Drying ($40\% \le RH_{in} \le 60\%$)**: Restricted to the **optimal night window (03:00–07:00)** to exploit maximum dew point spread.
+In Central Europe / Germany, the diurnal temperature and absolute humidity minimum occurs in early morning (~02:00–07:00, peak drying yield around 03:00–05:00 at ~7.6 g/m³ outdoor vapor content):
+*   **Urgent Drying ($RH_{in} > 60\%$ or Mold Critical)**: Evaluated and run 24/7 whenever psychrometric and temperature guards allow.
+*   **Routine Drying ($53\% \le RH_{in} \le 60\%$)**: Strictly restricted to the **optimal night window (02:00–07:00)** to exploit maximum dew point spread and prevent wasteful daytime runs.
+*   **Thermal Delta Guard**: If $T_{in} - T_{out} > 8.0^\circ\text{C}$ (very cold outside draft), spread requirement increases by +1.5°C (spread $\ge 3.5^\circ\text{C}$) and burst duration is throttled to 20 min max.
 
 ### 5. Duty Cycle & Thermal Equilibrium
 To allow cellar air and thermal wall mass to equilibrate and prevent non-stop continuous blowing:
-*   **Max Continuous Runtime**: 90 minutes.
-*   **Cooldown Rest**: 45 minutes pause after hitting max continuous runtime.
+*   **Max Continuous Runtime**: Strictly capped at **35 minutes** (scaled dynamically between 15 and 35 min based on dew point spread; no unlimited 9999 bypass).
+*   **Cooldown Rest**: **35 minutes pause** (1:1 duty cycle) after hitting max runtime to allow concrete and masonry moisture desorption.
 
 ---
 
@@ -53,11 +53,11 @@ To allow cellar air and thermal wall mass to equilibrate and prevent non-stop co
                                    │ YES
                       [ Overheating Safe (Tout vs Tin)? ]
                                    │ YES
-                      [ Cellar RH > Target (40% / 50%)? ]
+                      [ Cellar RH > Target Setpoint (55%)? ]
                                    │ YES
-                      [ Dew Point Spread > Threshold (2°C)? ]
+                      [ Urgent (>60%) OR Night Window (02-07)? ]
                                    │ YES
-                      [ Urgent (>60%) OR Night Window (03-07)? ]
+                      [ Dew Point Spread > Required Threshold? ]
                                    │ YES
                           ┌────────┴────────┐
                           ▼                 ▼
diff --git a/projects/shelly_taupunktluefter/scripts/Taupi-4.0.js b/projects/shelly_taupunktluefter/scripts/Taupi-4.0.js
index 91505b9..b02e329 100644
--- a/projects/shelly_taupunktluefter/scripts/Taupi-4.0.js
+++ b/projects/shelly_taupunktluefter/scripts/Taupi-4.0.js
@@ -13,6 +13,10 @@ var MAX_HEAT_CEIL    = ${max_indoor_temp_heating};
 var WINTER_IN_TH     = ${winter_temp_threshold_in};
 var TARGET_SUMMER    = ${target_humi_summer};
 var TARGET_WINTER    = ${target_humi_winter};
+var URGENT_HUMI_TH   = ${urgent_humi_threshold};
+var NIGHT_START_H    = ${night_window_start_hour};
+var NIGHT_END_H      = ${night_window_end_hour};
+var MAX_RUN_MIN      = ${max_runtime_minutes};
 var MIN_PAUSE_MIN    = ${min_pause_minutes};
 
 var LIM_BASE         = ${critical_humi_base};
@@ -28,6 +32,16 @@ var st_run = 0, st_target = TARGET_SUMMER, st_mold_th = 70.0, st_mold_crit = 0,
 var st_quality = 0, st_max_run_min = 0, st_gov_state = 0;
 var pid_out = -1, pid_in = -1;
 
+function getCurrentHour() {
+  var s = Shelly.getComponentStatus("sys");
+  if (!s || typeof s.time !== "string" || s.time.length < 2) return undefined;
+  var h0 = s.time.charCodeAt(0) - 48;
+  var h1 = s.time.charCodeAt(1) - 48;
+  if (h0 < 0 || h0 > 9 || h1 < 0 || h1 > 9) return undefined;
+  var h = h0 * 10 + h1;
+  return (h >= 0 && h <= 23) ? h : undefined;
+}
+
 function calcDewPoint(T, RH) {
   if (typeof T !== "number" || typeof RH !== "number" || isNaN(T) || isNaN(RH) || RH <= 0) return undefined;
   var a = (T >= 0) ? 17.27 : 21.875, b = (T >= 0) ? 237.7 : 265.5;
@@ -60,6 +74,7 @@ function evaluateDecision() {
   var reqSpread = DP_SPREAD_BASE;
   var targetHumi = TARGET_SUMMER;
   var govState = 2; // Comfort default
+  var deltaT = ti - to; // Positive when outside is colder than cellar
 
   if (ti > MAX_HEAT_CEIL) {
     // Warm Zone (> 20°C): Maximize cooling. Prevent heating if To > Ti.
@@ -71,8 +86,10 @@ function evaluateDecision() {
     // Comfort Zone (14°C - 20°C)
     govState = 2;
     targetHumi = TARGET_SUMMER;
-    if (to < (ti - 5.0)) {
-      reqSpread = DP_SPREAD_BASE + 1.0; // Strong cooling requires prime spread >= 3.0°C
+    if (deltaT > 8.0) {
+      reqSpread = DP_SPREAD_BASE + 1.5; // Very cold outside air requires premium spread >= 3.5°C
+    } else if (deltaT > 5.0) {
+      reqSpread = DP_SPREAD_BASE + 1.0; // Moderate cooling requires spread >= 3.0°C
     }
   } else {
     // Cold Zone (< 14°C)
@@ -85,30 +102,44 @@ function evaluateDecision() {
     }
   }
 
-  // 3. Target Humidity Gate
-  if (hi <= targetHumi) {
+  // 3. Target Humidity Gate with Hysteresis (2% lower to stop when already ventilating)
+  var effTarget = relay_on ? (targetHumi - 2.0) : targetHumi;
+  if (hi <= effTarget) {
     return { run: false, reason: "TARGET_REACHED", maxRun: 0, qual: 0, gov: govState };
   }
 
-  // 4. Dew Point Spread Gate
+  // 4. 2-Tier Scheduling: Urgent (>60% or mold crit) runs 24/7; Routine (<=60%) restricted to night window
+  var isUrgent = (hi > URGENT_HUMI_TH || isMoldCrit);
+  if (!isUrgent) {
+    var curHour = getCurrentHour();
+    if (typeof curHour === "number") {
+      var inWindow = (NIGHT_START_H <= NIGHT_END_H)
+        ? (curHour >= NIGHT_START_H && curHour < NIGHT_END_H)
+        : (curHour >= NIGHT_START_H || curHour < NIGHT_END_H);
+      if (!inWindow) {
+        return { run: false, reason: "OUTSIDE_NIGHT_WINDOW", maxRun: 0, qual: 0, gov: govState };
+      }
+    }
+  }
+
+  // 5. Dew Point Spread Gate
   var spread = di - do_;
   if (spread < reqSpread) {
     return { run: false, reason: "INSUFFICIENT_SPREAD", maxRun: 0, qual: Math.round(Math.max(0, spread * 20)), gov: govState };
   }
 
-  // 5. Dynamic Quality Runtime Formula
-  // Runtime [min] = (spread - DP_SPREAD_BASE) * 45 min
-  var maxRunMin = 0;
-  if (spread >= 5.0) {
-    maxRunMin = 9999; // Unlimited continuous run
-  } else {
-    maxRunMin = Math.round((spread - DP_SPREAD_BASE) * 45);
-    if (maxRunMin < 15) maxRunMin = 15;
-  }
+  // 6. Dynamic Quality Runtime Formula with Strict Upper Cap (MAX_RUN_MIN)
+  var maxRunMin = Math.round((spread - DP_SPREAD_BASE) * 20);
+  if (maxRunMin < 15) maxRunMin = 15;
+  if (maxRunMin > MAX_RUN_MIN) maxRunMin = MAX_RUN_MIN;
 
-  // Cold Zone burst throttle (max 25 min bursts when Ti < 14°C)
-  if (ti < WINTER_IN_TH && maxRunMin > 25) {
-    maxRunMin = 25;
+  // Cold Zone burst throttle (max 20 min bursts when Ti < 14°C)
+  if (ti < WINTER_IN_TH && maxRunMin > 20) {
+    maxRunMin = 20;
+  }
+  // Large Delta T throttle (max 20 min bursts when outside is >8°C colder)
+  if (deltaT > 8.0 && maxRunMin > 20) {
+    maxRunMin = 20;
   }
 
   var qualityScore = Math.min(100, Math.round(spread * 20));
@@ -139,7 +170,7 @@ function applyDecision(d) {
 
   if (d.run) {
     fan_run_sec += SCHALTZEIT_SEC;
-    if (d.maxRun < 9999 && fan_run_sec >= d.maxRun * 60) {
+    if (d.maxRun > 0 && fan_run_sec >= d.maxRun * 60) {
       d.run = false;
       last_reason = "BURST_LIMIT_REACHED";
       fan_pause_sec = MIN_PAUSE_MIN * 60;
diff --git a/projects/shelly_taupunktluefter/variables.tf b/projects/shelly_taupunktluefter/variables.tf
index 911e753..9a8ccce 100644
--- a/projects/shelly_taupunktluefter/variables.tf
+++ b/projects/shelly_taupunktluefter/variables.tf
@@ -47,13 +47,13 @@ variable "winter_temp_threshold_out" {
 variable "target_humi_summer" {
   type        = number
   description = "Target indoor relative humidity [%] during warm / summer mode"
-  default     = 40.0
+  default     = 55.0
 }
 
 variable "target_humi_winter" {
   type        = number
   description = "Target indoor relative humidity [%] during cold / winter mode (avoids over-cooling)"
-  default     = 50.0
+  default     = 55.0
 }
 
 variable "urgent_humi_threshold" {
@@ -65,7 +65,7 @@ variable "urgent_humi_threshold" {
 variable "night_window_start_hour" {
   type        = number
   description = "Start hour (0-23) for the optimal dew point drying window"
-  default     = 3
+  default     = 2
 }
 
 variable "night_window_end_hour" {
@@ -77,13 +77,13 @@ variable "night_window_end_hour" {
 variable "max_runtime_minutes" {
   type        = number
   description = "Maximum continuous fan runtime in minutes before enforcing a cooldown pause"
-  default     = 90
+  default     = 35
 }
 
 variable "min_pause_minutes" {
   type        = number
   description = "Minimum rest period in minutes after a ventilation burst to allow thermal/humidity equilibration"
-  default     = 20
+  default     = 35
 }
 
 variable "schaltzeit" {