HVAC technology has advanced by leaps and bounds over the past few decades. One of the biggest advancements is the development of variable-speed motors. They allow Vancouver HVAC systems to operate more efficiently and be much better at controlling temperatures. In this article, we’ll explain what variable-speed HVAC motors and systems are, how they work, and what major advantages they have over standard HVAC systems.

What Is a Variable-Speed HVAC System?

Central HVAC systems with a furnace, air conditioner, or heat pump are single-stage, two-stage, or variable-speed. These terms refer to the main heating or cooling unit as well as the blower that circulates air through the system. Standard systems are single-stage, which means the blower only has one speed. The furnace, AC, or heat pump only has one power setting.

Two-stage systems have a blower that has both high and medium speeds. A two-stage heat pump or air conditioner also has a two-stage compressor motor that can run at a lower speed. It pumps the refrigerant through the system more slowly.

The variable-speed blower motor in a variable-speed system has a huge number of settings and can continuously speed up or slow down when needed. It does this automatically based on the current temperature and the specific amount of heating or cooling needed to achieve or maintain the desired temperature. The variable-speed compressor motor in the AC or heat pump also works the same way and will speed up or slow down alongside the blower.

How Variable-Speed HVAC Systems Work

Variable-speed HVAC systems are designed to run almost continuously during the hotter and colder parts of the year. If you had your heating or AC switched off and then turned it on, the system would start out running at a low speed. It will then start gradually running faster and producing more heat or cooling so that the home reaches the desired temperature quickly.

As the thermostat senses that the air is nearing the desired temperature, the system will again start slowing down to prevent the home from getting hotter or colder than you want. Once the desired temperature is reached, the variable-speed blower and the heating or cooling unit will then continually adjust their speed or power settings. The temperature always stays where you want it to be.

The temperature will only drop one to maybe two degrees below the desired temperature when the system is heating or one to two degrees above when it’s cooling. Whenever this happens, the system will speed up slightly to produce enough heating or cooling to bring the temperature back to where it should be.

This means that the variable-speed blower, along with the variable-speed compressor motor in the heat pump or AC or the modulating gas valve in the furnace, will continually and automatically make minor adjustments. This allows for control over the amount of heating or cooling the system produces. The blower motor will also adjust based on the level of static pressure or air resistance in the duct system. This ensures the HVAC system always circulates the amount of air needed to prevent the temperature from fluctuating.

How Variable-Speed HVAC Systems Improve Comfort

One of the biggest advantages of a variable-speed HVAC system is that it will prevent issues with hot and cold spots in your home. The problem with single-stage systems is that they often produce so much heating or cooling that they rarely run for more than 15 minutes at a time. They’ll run longer if the home is much colder or warmer than it should be, but they will then cycle off and on a few times each hour once the desired temperature is reached. This creates several issues that typically lead to some parts of the home being colder and others being warmer.

One reason this happens is that the system won’t run long enough to fully heat cold areas like a basement. It will not fully cool warmer areas like the upper floors or rooms with large windows.

How a Variable-Speed HVAC System Lowers Energy Costs

Even though a variable-speed HVAC system will run continuously, it uses far less energy since it runs at a much lower speed instead of always at full power. This often results in variable-speed systems using half the amount of energy as single-stage systems.

One major difference with variable-speed HVAC motors is that they always start off running slowly. They will gradually increase their speed as needed. Single-stage motors must start at full power, which means it takes more electricity for the motors to start up. In fact, it typically takes around three to five times as much electricity for a single-stage motor to start compared to how much power it uses when it’s running.

Since 1997, Northwest HVAC Heating & Cooling has been providing reliable heating and air conditioning to customers in Vancouver and the Clark County area. We specialize in HVAC installation and can help you decide which type of system will work best for your home. We also service and repair every make, model, and type of HVAC system. To schedule a consultation and learn if a variable-speed system is right for your home, contact the Northwest HVAC Heating & Cooling team in Vancouver today.

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