diff --git a/control/actions.hpp b/control/actions.hpp
index d4dedba..325cbbd 100644
--- a/control/actions.hpp
+++ b/control/actions.hpp
@@ -255,6 +255,58 @@
     };
 }
 
+/**
+ * @brief An action to set the speed decrease delta and request speed change
+ * @details Provides the ability to determine what the net decrease delta each
+ * zone's fan speeds should be updated by from their current target speed, and
+ * request that speed change occur on the next decrease interval.
+ *
+ * @param[in] state - State to compare the group's property value to
+ * @param[in] speedDelta - Speed delta of the group
+ *
+ * @return Lambda function
+ *     A lambda function that determines the net decrease delta and requests
+ * a new target speed with that decrease for the zone.
+ */
+template <typename T>
+auto set_net_decrease_speed(T&& state, uint64_t speedDelta)
+{
+    return [speedDelta,
+            state = std::forward<T>(state)](auto& zone, auto& group)
+    {
+        auto netDelta = zone.getDecSpeedDelta();
+        std::for_each(
+            group.begin(),
+            group.end(),
+            [&zone, &state, &speedDelta, &netDelta](auto const& entry)
+            {
+                T value = zone.template getPropertyValue<T>(
+                        entry.first,
+                        std::get<intfPos>(entry.second),
+                        std::get<propPos>(entry.second));
+                // TODO openbmc/phosphor-fan-presence#7 - Support possible
+                // state types for comparison
+                if (value < state)
+                {
+                    if (netDelta == 0)
+                    {
+                        netDelta = (state - value) * speedDelta;
+                    }
+                    else
+                    {
+                        // Decrease is the difference times
+                        // the given speed delta
+                        netDelta = std::min(netDelta,
+                                            (state - value) * speedDelta);
+                    }
+                }
+            }
+        );
+        // Request speed decrease to occur on decrease interval
+        zone.requestSpeedDecrease(netDelta);
+    };
+}
+
 } // namespace action
 } // namespace control
 } // namespace fan
diff --git a/control/zone.cpp b/control/zone.cpp
index 5ed0c3a..1ca0b81 100644
--- a/control/zone.cpp
+++ b/control/zone.cpp
@@ -97,6 +97,7 @@
             std::get<actionPos>(event)(*this,
                                        std::get<groupPos>(event));
         }
+        //TODO openbmc/openbmc#1625 Start timer for fan speed decreases
     }
 }
 
@@ -105,11 +106,6 @@
 {
     for (auto& fan : _fans)
     {
-        //TODO openbmc/openbmc#1626 Move to control algorithm function
-        if (speed < _floorSpeed)
-        {
-            speed = _floorSpeed;
-        }
         fan->setSpeed(speed);
     }
 }
@@ -159,6 +155,35 @@
     _incSpeedDelta = 0;
 }
 
+void Zone::requestSpeedDecrease(uint64_t targetDelta)
+{
+    // Only decrease the lowest target delta requested
+    if (_decSpeedDelta == 0 || targetDelta < _decSpeedDelta)
+    {
+        _decSpeedDelta = targetDelta;
+    }
+
+    //TODO openbmc/openbmc#1625 Set decrease target speed when timer expires
+    // Only decrease speeds when no requested increases exist
+    if (_incSpeedDelta == 0)
+    {
+        // Target speed can not go below the defined floor speed
+        if ((_targetSpeed < _decSpeedDelta) ||
+            (_targetSpeed - _decSpeedDelta < _floorSpeed))
+        {
+            _targetSpeed = _floorSpeed;
+        }
+        else
+        {
+            _targetSpeed = _targetSpeed - _decSpeedDelta;
+        }
+        setSpeed(_targetSpeed);
+    }
+    // Clear decrease delta when timer expires
+    _decSpeedDelta = 0;
+    //TODO openbmc/openbmc#1625 Restart decrease timer
+}
+
 void Zone::getProperty(sdbusplus::bus::bus& bus,
                        const std::string& path,
                        const std::string& iface,
diff --git a/control/zone.hpp b/control/zone.hpp
index cc05959..f445472 100644
--- a/control/zone.hpp
+++ b/control/zone.hpp
@@ -179,6 +179,16 @@
         };
 
         /**
+         * @brief Get the decrease speed delta
+         *
+         * @return - The current decrease speed delta
+         */
+        inline auto& getDecSpeedDelta() const
+        {
+            return _decSpeedDelta;
+        };
+
+        /**
          * @brief Calculate the requested target speed from the given delta
          * and increase the fan speeds, not going above the ceiling.
          *
@@ -186,6 +196,14 @@
          */
         void requestSpeedIncrease(uint64_t targetDelta);
 
+        /**
+         * @brief Calculate the requested target speed from the given delta
+         * and increase the fan speeds, not going above the ceiling.
+         *
+         * @param[in] targetDelta - The delta to increase the target speed by
+         */
+        void requestSpeedDecrease(uint64_t targetDelta);
+
     private:
 
         /**
@@ -244,6 +262,11 @@
         uint64_t _incSpeedDelta = 0;
 
         /**
+         * Speed decrease delta
+         */
+        uint64_t _decSpeedDelta = 0;
+
+        /**
          * The vector of fans in this zone
          */
         std::vector<std::unique_ptr<Fan>> _fans;