Temperature performance
Supply and return temperatures are compared to actual operating conditions.
Cooling systems
Cooling service that separates airflow problems from refrigeration problems.
Poor cooling can come from the indoor coil, outdoor coil, blower, controls, electrical components, duct system or refrigerant circuit. We work through the system in a logical order.
Measured diagnosticsClear recommendationsField-tested processSouth Sound service
Diagnose firstFind the cause before recommending the fix.
Use the readingsMeasurements support the recommendation.
Explain the optionsKnow what matters now and what can wait.
Verify the resultApproved work is tested after completion.
HOW WE LOOK AT IT
More than a symptom.
A good cooling diagnostic starts with what the system is actually delivering to the home, then works backward through airflow, heat transfer, controls and refrigeration performance.
Indoor airflow
Filter, blower, indoor coil and duct restrictions are considered before blaming the refrigerant circuit.
Outdoor coil & fan
Coil cleanliness, fan operation and heat rejection are checked at the condenser.
Electrical components
Connections, contactor operation, capacitor condition and motor/compressor electrical performance as applicable.
Refrigeration circuit
Operating temperatures and pressures are interpreted with airflow and load, not in isolation.
Controls
Thermostat calls, safety controls and system sequencing are verified.
MEASUREMENTS
Readings have a purpose.
We use the measurements that fit the equipment and the complaint. Numbers are useful when they help explain what the system is actually doing.
Cooling delta T
A useful air-side performance check when interpreted with airflow and indoor conditions.
Capacitor condition
Helps identify weak components before they become a hard failure.
Motor / compressor amperage
Confirms electrical load and can reveal abnormal operating conditions.
Coil condition
Heat transfer suffers when indoor or outdoor coils are restricted.
FROM THE FIELD
“A frozen coil does not automatically mean “low refrigerant.” Restricted airflow can create similar symptoms, so airflow has to be proven before the refrigerant circuit is condemned.”
That field-first approach is what the Black Book service pages are built around: real troubleshooting logic translated into plain language for homeowners.
COMMON CALLS
Problems we are called to investigate.
System runs but does not coolStart with what the system is delivering indoors, then work through airflow, heat transfer, electrical operation and the refrigeration circuit.
Frozen indoor coilDetermine whether restricted airflow, coil condition, controls or refrigeration performance is allowing the coil to fall below freezing.
Weak airflowInspect filter, blower, indoor coil, duct restrictions and fan setup rather than assuming the cooling equipment itself is undersized.
Outdoor fan failureVerify the fan motor, capacitor or control electronics and the command to run before choosing a replacement.
Failed capacitor or contactorTest the component under the conditions that matter and inspect the connected load for signs of a larger electrical problem.
Dirty outdoor coilEvaluate whether debris is restricting heat rejection and clean the coil when condition and access make it appropriate.
Thermostat/control problemConfirm cooling calls, fan command and low-voltage control operation before moving to the refrigeration side.
Refrigerant performance issueInterpret pressures and temperatures only after airflow and operating conditions are known so the diagnosis has context.
FAQ
Questions homeowners ask.
Is a temperature split enough to diagnose an AC system?
No. It is useful data, but it has to be interpreted with airflow, indoor conditions and the refrigeration side.
Why is my outdoor unit running but the house is warm?
The issue may be airflow, heat transfer, controls, an electrical component or the refrigeration circuit.
Do you clean outdoor coils?
Coil cleaning may be part of maintenance when debris is affecting heat transfer.
Can a weak capacitor cause intermittent problems?
Yes. A deteriorating capacitor can contribute to hard starting or motor/compressor operation problems.
BLACK BOOK HOME SERVICES
Need help with air conditioning?
Tell us what the system is doing and what you have already noticed.