AC vs DC Irrigation Valves: What's the Difference?

Choosing the right irrigation valve is crucial to the efficiency and longer lifespan of the irrigation system. There are two primary irrigation valves: AC and DC valves. AC valves are powered by alternating current, and DC valves are powered by direct current.

It is important to understand the differences between both valve types and how these differences impact their performance. This article discusses the differences between AC and DC valves for an application to help you choose the one that suits your irrigation system.

What is an Irrigation Valve?

Irrigation valves regulate water flow and ensure that every plant receives the right amount. They make it easy to automate your irrigation system by connecting them with an irrigation controller. The valve allows you to address the specific needs of each landscaping area by dividing irrigation zones according to their needs. There are two main automatic irrigation valves: AC and DC. Let's discover the difference between them.

AC Irrigation Valves

AC valves operate on alternating currents found in AC power sources. AC or electric valves are widely used in irrigation systems powered by standard AC electricity. When activated by alternating current, they use an electromagnetic force that produces a linear motion. This linear motion regulates the opening and closing of the valve, which controls the water flow through the irrigation system.

There are various types of AC valves available: Anti-siphon valves, jar-top valves, and angle globe valves. These valves are highly reliable and versatile because they run on constant and stable AC power, meaning the valve will operate consistently over time. Make sure the power source is reliable to reduce disruptions in the irrigation schedule. AC valves are corrosion-resistant because they are made of robust materials like brass, stainless steel, and PVC. Moreover, AC valves require less maintenance than DC valves, which are more susceptible to wear and tear over time due to changes in electromagnet design.

Pros of AC Valves

• Can handle a variety of applications and higher-pressure
• Compatible with AC irrigation controllers
• Available in multiple types to help you choose the one that best meets your requirements
• More durable and versatile

Cons of AC Valves

• Require a stable source of AC power

DC Irrigation Valves

DC valves run on direct currents found in batteries and solar panels. They are commonly used in irrigation systems that run on batteries or solar panels or in areas with limited access to AC electricity. Like AC valves, they also use an electromagnetic force, but the linear motion produced is unidirectional. The main advantage of using DC irrigation valves is their portability. You can use them in remote locations or areas with poor power supplies because they don't require an AC power source.

DC solenoids work well with battery controllers and are best suited for small irrigation systems, while AC valves are perfect for watering a wide range of zones. Controllers send signals to valves telling them when to open and close the water flow. This automation allows you to precisely water your landscape and promote water conservation.

Pros of DC Valves

• Can run without any electrical power supply
• Energy-efficient and more environmental-friendly
• The best option for areas with limited or poor power supplies
• Can be used with a battery-powered controller

Cons of DC Valves

• Suitable for smaller systems

AC Valves vs DC Valves

Here is a comparison between the AC valve and the DC valve.

Noise and Vibrations

AC valves produce noise and vibrations. Although their design has shading rings, there is a high risk of vibrations if the component fails. In this case, the valve will produce a buzzing noise, overheating the coil and damaging the device.

With a DC valve, there is no risk of buzzing noise because the exciting current remains constant and doesn't change polarity.

Power Requirements

When it comes to power requirements, AC valves outperform DC valves. AC valves are larger and consume high power levels to create powerful currents in the coil that open the valve. It may seem like a disadvantage, but this is important. When the valve opens, the current required to hold the armature in position drops to a low level. This helps in reducing power consumption.

DC-operated valves use small components to create fast actions from small devices. They require a constant and stable flow of current to operate, which results in a high-power consumption compared to AC valves.

Operating Time

The operating time of AC valves is not constant because it changes with the operation frequency and affects the heat buildup in the coil.

The operating time of the DC valve remains constant regardless of frequency because the current travels only in one direction.

Excitation Current

The excitation current of the AC valve varies depending on the stroke.

In a DC valve, the excitation current depends on the internal resistance of the coil and voltage, and it remains constant regardless of stroke.

Service Lifetime

The service life of irrigation valves depends on wear and tear between the plunger and valve pipe. AC valves usually experience faster wear if they start buzzing.

How to Choose the Right Irrigation Valve for Your Irrigation System

When choosing between AC and DC valves, consider the available power source and ensure the valve is compatible with the controller and other irrigation system components. An AC valve is the best choice if your system is powered by AC electricity. On the other hand, if your system is powered by a solar panel or battery, a DC valve is the right choice. If you do not have a 230-240V power source or three-pin plug port, the only option is a DC valve.

AC valves are 24 volts, and DC valves are 12 volts. Each type has pros and cons, so deciding which is best depends on your intended use and preferences. DC valves are much better because they don't buzz or overheat. However, DC valves do not work as fast. So, if the application demands a quick valve opening response, it is best to use an AC valve. Check out this Valve Buying Guide to select the right one for your irrigation system.

The correct irrigation valve can play a key role in the efficiency and longevity of your irrigation system. At DripWorks, we carry a wide range of high-quality AC and DC valves to help you control the water flow to your irrigation system. Our irrigation products are designed with utmost durability to make your irrigation system water-efficient and reliable.