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Understanding The Details Of Two-Stage Vs. Variable AC Systems

Traditional HVAC systems are single-stage units. This description might sound like technical jargon, but it's relatively easy to understand. If your home uses a standard air conditioning system, it most likely has precisely two modes: on and off. Single-stage furnaces and air conditioners can run at full blast or not at all, with nothing in between.

Think about how your home tends to feel on a hot summer day, and you'll recognize the behavior of a single-stage system. You'll most likely notice the temperature in your home becoming uncomfortably warm before you hear the AC kick on and deliver some frigid air. With a single-stage system, this hot and cold cycle will repeat all day and all summer long.

What Are the Alternatives?

Variable and two-stage systems offer a better way to cool your house. These systems have "in-between" settings that allow them to run even when you don't need full cooling power. These lower power modes cool more slowly, allowing the system to maintain a temperature closer to your thermostat set point without wild swings between hot and cold.

As the name implies, a two-stage system has a full-power and a medium-power mode. These two modes allow the system to adjust to lower cooling loads, keeping you more comfortable on days that don't require high-power cooling. Two-stage systems also work well for homes with good insulation that may not heat up quickly.

A variable system can vary its power from full speed to almost nothing. As a result, these systems can accommodate nearly any interior conditions, maintaining a steady temperature while typically using less energy. Where a two-stage system helps smooth out hot and cold cycles, a variable system can often eliminate them.

Are There Any Downsides?

Two-stage and variable systems are more efficient than single-stage systems and generally provide much more comfort. However, there are a handful of downsides. First and foremost, these systems cost more upfront and may cost more to install. Two-stage systems may be slightly more expensive than single-stage units, but variable systems often cost much more.

Maintenance may also be a concern. Single-stage systems still dominate the market, so parts are cheaper and more widely available. Even the best-maintained system will eventually suffer failures, so long-term operating costs are worth considering. A high-end variable system may require specialized parts and labor to repair and maintain.

However, if these systems fit your budget and you're willing to deal with the downsides, they can be an excellent way to revolutionize your home's cooling performance. Since both two-stage and variable units also provide high efficiency, they're also an excellent and high-tech way to bring down your monthly cooling costs!

Contact an air conditioning contractor for more information.