Your role in this month’s troubleshooting situation is providing a second opinion on a failed compressor diagnosis. The customer’s complaint is that the unit isn’t cooling properly — the equipment is a heat pump package unit that is just past the warranty period for the compressor.
System design, performance, and service conditions must be evaluated when retrofitting with a zeotropic or near-azeotropic refrigerant blend. Always follow the refrigerant manufacturer’s retrofit guidelines before retrofitting with any refrigerant, or system performance could be affected and/or injury may occur.
Measuring the evaporator’s superheat value is an important part of analyzing a system’s performance. If a lower-than-normal value is measured, too much refrigerant is entering the evaporator for the heat load. If a higher-than-normal value is measured, too little refrigerant is entering the evaporator for the heat load.
Bob and Tim were at the shop after a day of service calls. The weather was still hot, 93°F, and Bob said, “We just did a service call with a system that was overcharged and had an orifice expansion device. I would like to go into further details with you on a system with a thermostatic expansion valve (TXV) for an expansion device.”
Bob and Tim were on their way to a service call with a new customer. When they got to the job, the customer explained, "The unit was not cooling and I had a company come out for a service call. The unit seemed to work OK last week when it was a little cooler outside, but this week it has warmed up and the unit is not functioning as well."
What is a super tech? A super tech is one who eats, sleeps, and breathes HVAC. He may be a contractor, manager, or technician, but, above all, he is a perfectionist. And his greatest enemy is the callback.