Because optimum summer cooling and efficiency requires more than an “on/off” approach, variable-speed HVAC systems are rapidly becoming the standard for precise comfort control and lower energy costs. The heart of your central A/C system is the compressor, a powerful electric motor that compresses refrigerant which extracts heat from your home. A standard single-speed compressor typically cycles on and off multiple times daily, each time the thermostat signals for cooling. The result: your air conditioner provides 100% cooling output when the compressor’s on—but zero output every time the compressor cycles off.
Drawbacks of on/off cooling include:
Inconsistent temperature control.
Indoor temperature constantly swings between comfortably cool and less-comfortable warm conditions as the compressor repeatedly cycles on and off.
Higher indoor humidity.
Extracting humidity is a critical function of cooling. Each time a single-speed compressor turns off, indoor humidity begins accumulating again and comfort declines.
Increased wear and tear.
Constant on/off cycling increases wear and tear on the compressor motor—typically the most expensive component in your central A/C system.
Systems integrate a compressor that runs nearly continuously, constantly adjusting speed and A/C output to meet cooling demands of the moment. Here are reasons why a variable-speed HVAC system works better:
Instead of shutting off when the house temperature matches the thermostat setting, the variable-speed compressor slows to approximately 40% output. This maintains indoor temperature precisely—in some cases, with an accuracy of plus or minus one degree—while eliminating the noticeable temperature swings of single-speed, on/off operation.
Humidity extraction is more effective when the A/C compressor runs continuously, instead of turning on and off. A variable-speed HVAC system continues to control indoor humidity at all times.
Lower cooling costs and less wear. A 220-volt standard A/C compressor draws substantial amps to start the motor as it constantly cycles off and on. Conversely, a variable-speed compressor that runs continuously at lower output consumes less electricity and provides lower operating costs. It also incurs less wear than on/off operation, meaning longer component life.
For more about the benefits of a variable-speed HVAC system, in the Coastal Bend contact the cooling pros at CCAC.
Our goal is to help educate our customers in Corpus Christi, Texas about energy and home comfort issues (specific to HVAC systems). For more information about your HVAC system, download our free Home Comfort Guide or call us at 361-678-2495.