diff --git a/ontology/yaml/resources/HVAC/entity_types/ABSTRACT.yaml b/ontology/yaml/resources/HVAC/entity_types/ABSTRACT.yaml
index c9398cc64..eddf5a444 100644
--- a/ontology/yaml/resources/HVAC/entity_types/ABSTRACT.yaml
+++ b/ontology/yaml/resources/HVAC/entity_types/ABSTRACT.yaml
@@ -6777,6 +6777,7 @@ VMADC:
   - CONTROL
 
 MDSDC:
+  guid: "1ee9e02c-1ad9-4451-aa55-7b6655bfdc50"
   description: "Motion-dependent supply damper control."
   is_abstract: true
   uses:
diff --git a/ontology/yaml/resources/HVAC/entity_types/FAN.yaml b/ontology/yaml/resources/HVAC/entity_types/FAN.yaml
index b329f5aa3..aac69a0c6 100644
--- a/ontology/yaml/resources/HVAC/entity_types/FAN.yaml
+++ b/ontology/yaml/resources/HVAC/entity_types/FAN.yaml
@@ -771,6 +771,7 @@ FAN_SS_MSM:
   - MSM
 
 FAN_SS_SRC:
+  guid: "44c1a03d-8639-446e-ab61-9f7b98016304"
   description: "Basic fan with start/stop and schedule run command."
   is_canonical: true
   implements:
diff --git a/ontology/yaml/resources/HVAC/entity_types/VAV.yaml b/ontology/yaml/resources/HVAC/entity_types/VAV.yaml
index 0ec08a004..ee0404ece 100644
--- a/ontology/yaml/resources/HVAC/entity_types/VAV.yaml
+++ b/ontology/yaml/resources/HVAC/entity_types/VAV.yaml
@@ -534,6 +534,7 @@ VAV_HWZTC_CHWZTC_DTM:
     - DTM
 
 VAV_MDSDC:
+  guid: "2a74ea42-38ec-4832-ba83-cfa2d29486b1"
   description: "A zone VAV with ventilation control based on a motion sensor."
   is_canonical: true
   implements: