Evaluating Comfort Cooling System Performance, HVAC | Heating, Air Conditioning Marietta GA | 770-444-9142

EVALUATING COMFORT COOLING SYSTEM PERFORMANCE This is the first in a series of articles on the subject of HVACR system performance, and I think it’s appropriate that we begin by taking a nuts-and-bolts look at some of the simple tests technicians can accomplish with standard test equipment when they are checking a comfort cooling system for proper operation and optimum performance. As we all know, the “beer can cold” suction line test went by the wayside long ago, and refrigeration and air flow system performance analysis requires a more sophisticated approach. The illustration in Figure One shows the data collection points I’ll be discussing. Of course, one of the most common method employed to evaluate a system is a standard set of compound gauges attached the high and low pressure access valves (shown to the left of our illustration at the outdoor segment of a typical split system). Unfortunately, this is often the only step taken to find out if a comfort cooling system is operating as efficiently as possible, however there’s much more beyond this basic process that should be accomplished in the way of performance checks. Let’s start with one that is very simple and easy to do, yet tells you a lot about the system. You’ll note that in addition to the pressure measurements that can be taken at the outdoor unit, we are also explaining that you should test the temperature of the discharge line. This is a temperature test that should be accomplished about 6 inches from the compressor, and the maximum reading you should get is 225 Degrees F. The bottom line on this test is simple: If you’re getting a 225-degree reading at this point on the discharge line, then the temperature inside the compressor itself is going to be approximately 300-Degrees. And, a temperature higher than that in a compressor crankcase will mean that some of the oil is vaporizing, which affects the lubrication process. Of course, the ultimate result of this situation is premature compressor failure. How does a compressor discharge temperature get too high? Again, unfortunately, a system overcharge is often the culprit….a system overcharge that is the result of poor service procedures like “adding a little gas” in an effort to increase the performance of the equipment. The percentage of overcharged residential comfort cooling systems is literally staggering, and they are not only failing prematurely, requiring sealed system service that increases the incidences of refrigerant discharge into the atmosphere, but they are operating inefficiently due to increased current draw….a far cry from proper system performance. HVAC Repairs Atlanta GA