An Air Conditioner is made of several parts that must work together. A problem with one small part can affect the comfort of the entire home. During this Heating and Cooling project, the Fast Affordable Air technician inspected equipment in the attic and tested the outdoor condensing unit.
The pictures show a Carrier Performance Boost 80 furnace and blower cabinet connected to a Tempstar indoor coil. The outdoor section was checked with Yellow Jacket refrigerant gauges and a Fieldpiece SC620 electrical meter.
This type of detailed inspection helps find weak electrical parts, incorrect refrigerant conditions, loose duct connections, and other problems that may cause poor Cooling. Fast Affordable Air provides AC repair in Las Vegas, Henderson, North Las Vegas, and nearby areas of Clark County.
Inspecting the Carrier Furnace and Blower Cabinet
The first picture shows a Carrier Performance Boost 80 furnace installed in the attic. Although this cabinet is called a furnace, it also contains the blower that moves air during the Cooling season.
The blower works like a large fan. It pulls warm air from the home, pushes it across the cold indoor coil, and sends the cooled air back through the duct system. If the blower is dirty, weak, or running at the wrong speed, the central AC may not move enough air.
During an inspection, the technician checks the cabinet panels, wiring, blower area, and nearby duct connections. The area around the equipment is also checked for signs of air leakage, damaged insulation, moisture, or restricted airflow.
Checking the Tempstar Indoor Coil Cabinet
The second picture shows the Tempstar indoor coil cabinet connected to the Carrier furnace. The indoor coil is also called the evaporator coil. It is the part that becomes cold when the Air Conditioning system is operating.
Warm indoor air passes across this coil. The refrigerant inside the coil absorbs heat from the air. The blower then sends the cooled air into the home.
The metal joints around the coil cabinet appear to be covered with HVAC foil tape. HVAC foil tape is a strong metal-backed tape made for Heating and Cooling systems. It helps seal small openings where conditioned air could escape into the attic.
A tight connection is important in a hot attic. Air leaking from the cabinet or plenum can waste energy before it ever reaches the rooms. A plenum is the large metal air box that connects the equipment to the ductwork.
Opening the Access Area and Checking Air Temperature
Another picture shows an insulated access panel near the attic ductwork. Opening this area gives the technician a better view of the air path and nearby equipment.
A temperature instrument can also be seen near the duct opening. Temperature readings help the technician compare the warm air entering the central Air Conditioner with the cooler air leaving it.
This difference is called the temperature split. For example, if 80-degree air enters the system and 60-degree air comes out, the temperature split is 20 degrees. The correct result can change based on indoor humidity, airflow, outdoor temperature, and the condition of the equipment.
Temperature readings should not be used alone. They are compared with refrigerant pressure, electrical readings, airflow, and the condition of the indoor coil.
Inspecting the HVAC Control Board
The control board and wiring inside the attic equipment are visible in another picture. The control board acts like the brain of the HVAC system. It receives signals from the thermostat and tells different parts when to turn on or off.
Before opening this section, electrical power should be turned off. The technician checks for loose wires, dark or burned areas, damaged terminals, weak relays, and signs of overheating.
A relay is an electrical switch controlled by the system. When a relay fails, the blower, compressor, or another part may not receive the power it needs.
Finding a loose connection early may help prevent damage to a motor or control board. It can also reduce problems such as short cycling. Short cycling happens when an Air Conditioner starts and stops too often instead of completing a normal Cooling cycle.
Testing the Capacitor with a Fieldpiece Meter
One Fieldpiece SC620 meter picture appears to show a capacitance reading close to 46 microfarads. A microfarad is a unit used to measure the strength of a capacitor.
A capacitor is a small electrical part that helps a compressor or fan motor start and continue running. It works a little like a rechargeable push of electrical energy.
The technician compares the meter reading with the rating printed on the capacitor. A small difference may be allowed, depending on the part’s listed tolerance. A weak capacitor can make the compressor struggle, cause the outdoor fan to stop, increase electrical use, or prevent the AC from starting.
Regular electrical testing is part of a careful air conditioning tune-up.
Measuring the Outdoor Unit’s Electrical Load
The second Fieldpiece meter picture appears to show an operating current close to 9 amps. Amps measure the amount of electrical current being used by a component.
The technician compares this number with the information printed on the equipment label. A compressor or fan motor that pulls too much current may be overheating, working against high pressure, or beginning to fail.
A very low reading can also point to a problem. The technician uses the current measurement together with voltage, capacitor strength, refrigerant pressure, and operating temperature to understand what the system is doing.
Checking Refrigerant Pressure with Yellow Jacket Gauges
The Yellow Jacket manifold gauge set was connected to the outdoor condensing unit. A manifold is a tool with two pressure gauges and several hoses. The blue gauge normally measures the low-pressure side, while the red gauge measures the high-pressure side.
Refrigerant is the special fluid that carries heat from inside the home to the outdoor unit. It changes between a liquid and a vapor as it travels through the system.
The gauges help the technician see how the refrigerant is moving through the central Air Conditioning system. However, pressure alone does not show whether the refrigerant charge is correct. The readings must be compared with outdoor temperature, indoor temperature, airflow, equipment information, superheat, and subcooling.
Superheat measures how much the refrigerant vapor has warmed after boiling inside the indoor coil. Subcooling measures how much the liquid refrigerant has cooled after changing from vapor to liquid in the outdoor coil. These measurements help prevent adding too much or too little refrigerant.
The final gauge picture shows another pressure check after the system had been operating. Allowing the system to run gives the pressures time to become more stable. This helps the technician compare the first readings with the system’s normal running condition.
Benefits of Testing the Complete System
The Carrier furnace, Tempstar indoor coil, outdoor condenser, control board, capacitor, refrigerant lines, and ductwork must operate as one system. The logo on the cabinet does not replace proper installation and testing.
A complete diagnostic and AC maintenance service can provide several benefits.
- More even Cooling throughout the home
- Better airflow from the supply vents
- Less conditioned air escaping into the attic
- Lower stress on the blower and compressor
- Earlier warning of weak electrical parts
- More accurate refrigerant testing
- Fewer unexpected breakdowns during hot weather
- Reduced energy waste caused by a struggling system
