Cooling capacity or refrigeration fault
Commercial symptom guide · ICY AC
The AC is running. The building is still hot.
A running fan, cold pipe or completed repair does not prove that enough heat is leaving the occupied space. The useful question is where the heat balance breaks under the condition that produces the complaint.
What people notice
Reported symptoms
- Thermostat reaches setpoint slowly or never
- Supply air feels cool but the room stays hot
- One repair restores equipment operation without restoring comfort
What may interact
Plausible systems
Low supply airflow or blocked return path
Solar, envelope, outdoor-air or internal load above the operating removal rate
Control schedule, sensor, staging or power problem
The first useful field packet
Collect evidence that can change the decision.
Record the building under the condition that produces the complaint. Keep direct observations, measurements, trade findings and hypotheses visibly separate.
- 01
Complaint location, time, weather and occupancy
- 02
Equipment identity, mode, setpoint and runtime
- 03
Occupied-zone, upper-space, supply, return and outdoor conditions
- 04
Qualified trade findings tied to the same operating state
Avoid expensive loops
Do not spend past the proof.
- Replacing equipment before verifying load and distribution
- Treating a thermostat reading as a full diagnosis
- Adding spot cooling without checking electrical, condensate and pressure interaction
Straight answers
Questions businesses ask first.
Why is my commercial AC running but not cooling the building?
The cause can be equipment capacity, refrigerant, airflow, controls, power, ventilation, infiltration, solar gain or several faults at once. ICY sequences measurements so the next scope follows evidence.
Does cold supply air mean the system is working correctly?
No. Supply temperature is one observation. Delivered airflow, runtime, return conditions, zone load and heat rejection determine whether the space is actually being cooled.
Should I replace the rooftop unit?
Replacement may be justified, but age or one failed component is not enough by itself. Confirm the load, distribution, controls, repairability and acceptance target first.
This guide cannot diagnose the building, promise a provider or authorize regulated work. ICY qualifies the exact location, responsible parties, credentials, travel, price, schedule and acceptance criteria before work begins.
Complaint · operating state · evidence
Turn this symptom into one controlled scope.
Send the address, time pattern, equipment labels and prior findings. ICY will define the next proof gate.