Variable Frequency Drive (VFD) Pool Pumps: Cost Savings & Efficiency

In the sun soaked Southern United States, keeping a pool crystal clear and ready for your family throughout the summer months requires running your pool pump at least eight or twelve hours a day.  This makes your choice of pool pump crucial for maintaining water quality but also for managing energy costs.  Enter the Variable Frequency Drive (VFD) pool pump – a modern solution that offers advantages over traditional single-speed pumps in terms of sanitation, durability, efficiency, and total electrical costs.   

What is a VFD pump?  Brands and models available?  Benefits to buying one? We’ll cover all these questions and more—stick with us to find out!

What is a Variable Frequency Drive (VFD) Pool Pump ?

A Variable Frequency Drive (VFD) pump, also known as a variable speed or variable flow pump, is an advanced type of pool pump. It allows users to adjust the motor’s speed to match the specific needs of their pool. Unlike single-speed pumps, which operate at a constant maximum speed, VFD pumps can run at various speeds. This provides greater control over water flow and energy consumption. 

Understanding Variable Frequency Drives (VFD): Variable Speed and Variable Flow Pumps

So, what does “variable frequency” mean? A VFD uses an electronic controller to adjust the frequency of the electricity supplied to the motor. By changing this frequency, the VFD controls the motor’s speed. This allows it to operate more efficiently based on demand. There are two main types: variable speed (VS) and variable flow (VF). Both models may include an optional Safety Vacuum Release System (SVRS) and feature a digital control panel for easy programming.

The simplest type of VFD is the variable speed pump, or ‘VFD-VS.’ This allows users to program the desired pump speed in RPMs, ranging from 800 RPM (minimum) to 3450 RPM (maximum). The VFD adjusts the electricity supplied to ensure it runs precisely at the selected speed. Users can also set a schedule to run the pump at different speeds and times.

Variable Frequency Drive (VFD) – Variable Flow (VFD-VF)

A variable flow model, or ‘VFD-VF,’ operates similarly but differs in a key way: instead of setting a motor speed, users program a desired flow rate, expressed in gallons per minute (GPM). The VFD controller adjusts the motor’s speed to maintain that flow rate. This feature is particularly beneficial for pools with multiple accessories (like water features or salt systems) or cartridge filters. For example, as a cartridge filter becomes dirty, a constant-speed pump typically reduces flow. In contrast, a variable flow pump automatically adjusts to maintain the desired flow rate.

Safety Features: The Importance of a Safety Vacuum Release System (SVRS)

Finally, both types of VFD pumps can include an important safety feature: a Safety Vacuum Release System (SVRS). This electronic safety switch automatically turns off the pump if it detects a high level of vacuum, preventing potential hazards. An SVRS is essential for pools or spas with a single main drain or multiple drains located less than three feet apart. A qualified swimming pool contractor can assess whether your pool requires an SVRS. 

Benefits of VFD Pumps: Durability, Longevity, and Enhanced Circulation

Benefits of VFD Pumps: Durability and Longevity

Operating a pool pump at maximum speed puts substantial stress on internal components (such as seals and impellers) and generates excessive heat. By running at lower speeds, friction and heat output are reduced. This significantly extends the pump’s lifespan and decreases maintenance needs. This is especially beneficial for pools in the Southwest, where year-round usage can accelerate wear.

Reduced Stress on Other Pool Components

Additionally, a variable speed pump reduces stress on other pool components. Single-speed pumps are often oversized to ensure flow, even when filters are dirty. A variable speed pump allows for more efficient operation, leading to less strain on filters, heaters, and salt systems.

Enhanced Circulation and Sanitation

A VFD pump enhances water sanitation by enabling continuous and optimized circulation. By adjusting the pump’s speed, you can run it for longer periods at a lower cost. Continuous filtration—even at reduced flow rates—significantly minimizes algae growth and improves overall pool cleanliness. This ability to fine-tune the pump’s speed also aids in the even distribution of chemicals, maintaining balanced water chemistry and reducing the frequency of chemical adjustments.

For more insights on how filtration and circulation affect your pool’s water chemistry, check out our article How Can Filtration and Circulation Affect Your Pool’s Water Chemistry?.

Cost Savings: A Smart Investment

Considering these benefits, it’s vital to examine the financial implications of choosing a VFD pump. The initial investment may seem high, but long-term cost savings can be substantial. A unique aspect of electric motors is that a pump running at 50% of its maximum speed consumes only 25% of the electricity compared to running at full speed.

Here’s a breakdown of potential annual savings with a VFD pump:

Conclusion: Making the Right Choice

For pool owners, choosing between a VFD and a single-speed pump is not just about preference; it’s a smart investment. The advantages of a VFD pump extend beyond energy savings. They enhance durability and longevity, reducing wear and tear on both the pump and other pool equipment.

The ability to fine-tune pump speed improves water circulation and sanitation, ensuring a cleaner, more balanced pool. The cost savings illustrated in the chart show that the initial investment in a VFD pump pays off over time.

As energy prices rise and sustainability becomes increasingly important, transitioning to a VFD pump is a practical choice and a proactive step toward responsible pool ownership. By opting for a VFD pump, you’re investing in a greener, more efficient future for your home.