What do low pressure gauge readings of 5 psi and high pressure of 105 psi at 85°F indicate?

Low pressure gauge readings of 5 psi and high pressure of 105 psi at 85°F typically indicate that there is too little refrigerant in the system, which corresponds to a low refrigerant level. In a normal operating air conditioning system, you would expect to see higher suction (low side) pressures that align with the ambient temperature and higher discharge (high side) pressures which reflect the system's capability to transfer heat effectively.

The low pressure reading at 5 psi suggests that the refrigerant cannot maintain adequate pressure in the low side of the system, potentially leading to reduced cooling efficiency and operation. This level is significantly below the expected range for a system operating at 85°F. The high pressure at 105 psi, while it might seem normal or slightly elevated, does not accurately reflect the condition of the system due to the imbalance created by the low refrigerant level.

Low refrigerant can lead to problems like compressor overheating, system inefficiency, and even potential compressor damage if not addressed. Therefore, the readings from the gauges give clear indicators of insufficient refrigerant in the system, affirming the understanding that low pressure at this level typically means the refrigerant is inadequate for proper operation.