diff --git a/ontology/yaml/resources/HVAC/entity_types/ABSTRACT.yaml b/ontology/yaml/resources/HVAC/entity_types/ABSTRACT.yaml
index 5fcb3febb..cb989d9b3 100644
--- a/ontology/yaml/resources/HVAC/entity_types/ABSTRACT.yaml
+++ b/ontology/yaml/resources/HVAC/entity_types/ABSTRACT.yaml
@@ -585,6 +585,42 @@ VSFC:
   - speed_frequency_command
   - speed_frequency_sensor
 
+FSS4X:
+  guid: "73a049b2-274c-4dcc-b2ca-4126c2485b51"
+  description: "Start/stop for four fans."
+  is_abstract: true
+  implements:
+  - OPERATIONAL
+  uses:
+  - fan_run_command_1
+  - fan_run_command_2
+  - fan_run_command_3
+  - fan_run_command_4
+  - fan_run_status_1
+  - fan_run_status_2
+  - fan_run_status_3
+  - fan_run_status_4
+
+FVSC4X:
+  guid: "10267aa0-4a96-4894-af3c-d44eda0ce31f"
+  description: "Variable speed control for four fans."
+  is_abstract: true
+  implements:
+  - OPERATIONAL
+  opt_uses:
+  - fan_speed_frequency_sensor
+  uses:
+  - fan_run_command_1
+  - fan_run_command_2
+  - fan_run_command_3
+  - fan_run_command_4
+  - fan_run_status_1
+  - fan_run_status_2
+  - fan_run_status_3
+  - fan_run_status_4
+  - fan_speed_percentage_command
+
+
 SFVSC:
   guid: "ac42c5d1-24d5-4433-b5e5-4ae8843e9ca8"
   description: "Variable speed control for supply fans."
diff --git a/ontology/yaml/resources/HVAC/entity_types/CH.yaml b/ontology/yaml/resources/HVAC/entity_types/CH.yaml
index 4ddbe7216..32cba1ebd 100644
--- a/ontology/yaml/resources/HVAC/entity_types/CH.yaml
+++ b/ontology/yaml/resources/HVAC/entity_types/CH.yaml
@@ -310,6 +310,22 @@ CH_SS_SCHWTC_CHPM_REFSM_IGM_DXSWC_CHWSWISOVM_CHWDPM:
   - CHWSWISOVM
   - CHWDPM
 
+CH_SS_SCHWTC_CHPM_REFSM_IGM_CHDXSC_CHWSWISOVM_CHWDPM_CWDT:
+  guid: "1f62d2f7-76e4-455b-b6cc-6689aa47e90d"
+  description: "Water-cooled chiller."
+  is_canonical: true
+  implements:
+  - CH
+  - SS
+  - SCHWTC
+  - CHPM
+  - REFSM
+  - IGM
+  - CHDXSC
+  - CHWSWISOVM
+  - CHWDPM
+  - CWDT
+
 CH_SS_SCHWTC_DXSWC_IGM_CWDT_CHWRWISOVPM_CWRISOVPM_CHPM_REFSM:
   guid: "17092e52-d7cf-4b7e-a353-2f94bdde3844"
   description: "Water-cooled chiller."
diff --git a/ontology/yaml/resources/HVAC/entity_types/CHWS.yaml b/ontology/yaml/resources/HVAC/entity_types/CHWS.yaml
index c8420d655..313ac2f18 100644
--- a/ontology/yaml/resources/HVAC/entity_types/CHWS.yaml
+++ b/ontology/yaml/resources/HVAC/entity_types/CHWS.yaml
@@ -180,6 +180,16 @@ CHWS_SWTC_WDPC_CLPM_WFRC_BYPVPM:
   - WFRC
   - BYPVPM
 
+CHWS_SWTC_WDPC_BYPVFRC:
+  guid: "1eb7c5c6-205b-409e-8e0a-2944e2994434"
+  description: "Chilled water system with supply temperature, differential pressure and bypass valve flowrate control."
+  is_canonical: true
+  implements:
+  - CHWS
+  - SWTC
+  - WDPC
+  - BYPVFRC
+
 CHWS_SWTC_WDPC_BYPVFRC_CLPM:
   guid: "2b835b66-3db9-499e-97f4-1e22540df676"
   description: "Chilled water system with supply temperature, differential pressure, bypass valve flowrate control, and cooling thermal monitoring."
diff --git a/ontology/yaml/resources/HVAC/entity_types/DC.yaml b/ontology/yaml/resources/HVAC/entity_types/DC.yaml
index 46cc2a93a..225b2c550 100644
--- a/ontology/yaml/resources/HVAC/entity_types/DC.yaml
+++ b/ontology/yaml/resources/HVAC/entity_types/DC.yaml
@@ -25,6 +25,18 @@ DC_SS_SWTC:
   - SS
   - SWTC
 
+DC_SS_FSS4X_FVSC4X_SWTC_WDPM:
+  guid: "1e1ddaf9-d9e7-46c2-8026-964c183a22c4"
+  description: "Closed loop sensible cooler with four fans and differential pressure monitoring."
+  is_canonical: true
+  implements:
+  - DC
+  - SS
+  - FSS4X
+  - FVSC4X
+  - SWTC
+  - WDPM
+
 DC_SS_SWTC_RWISOVM:
   guid: "70aab981-f70d-417f-ac7e-692b24fe5908"
   description: "Typical dry-cooler (dry air cooler with isolation valve on the return side)."
diff --git a/ontology/yaml/resources/fields/telemetry_fields.yaml b/ontology/yaml/resources/fields/telemetry_fields.yaml
index 55ec3f720..4c4d3365a 100644
--- a/ontology/yaml/resources/fields/telemetry_fields.yaml
+++ b/ontology/yaml/resources/fields/telemetry_fields.yaml
@@ -263,12 +263,12 @@ literals:
 - exhaust_fan_speed_percentage_sensor:
     fixed_min: 0.0
     fixed_max: 100.0
-- fan_run_status:
-  - ON
-  - OFF
 - fan_speed_percentage_command:
     fixed_min: 0.0
     fixed_max: 100.0
+- fan_speed_frequency_sensor:
+    flexible_min: -0.5
+    flexible_max: 65
 - flowrate_sensor:
     flexible_min: -0.000315451
     flexible_max: 0.315451
@@ -1034,6 +1034,12 @@ literals:
 - exhaust_air_differential_flowrate_setpoint:
     flexible_min: 0.0
     flexible_max: 23.59737216
+- fan_run_command:
+  - ON
+  - OFF
+- fan_run_status:
+  - ON
+  - OFF
 - fan_speed_mode:
   - OFF
   - LOW