Some irrigation controllers just aren’t that smart. They’re the older, conventional controllers programmed to run for specific times and durations. Whatever the season, plant material, or current weather conditions, conventional controllers relentlessly keep to their watering schedule, unless someone intervenes and turns them off. The result can be overwatering, runoff, underwatering and high water bills.
In comparison, smart controllers are able to adjust the watering schedule according to actual conditions on the site by monitoring such factors as the weather, soil conditions, evaporation, and plant water use.
The “Smart” controllers available today are the Wi-Fi weather-based controllers. They receive real-time weather information from online weather services on a frequent basis, sometimes even hourly, that allows them to update their irrigation schedules.
Advantages of Wi-Fi Controllers
- Using real-time weather information, the controller can adjust irrigation quickly for the current conditions, conserving water and saving money.
- The irrigation system can be programmed and run from a smartphone, tablet, or computer. Programming and adjustments can also be done manually at the controller.
- The controller smartphone app for iOS and Android is user-friendly and easy to understand. The ease of use makes it faster to program the necessary information for each zone, such as plant and soil type, root depth, amount of shade and sun, and the degree of land slope.
- The design of the Wi-Fi controller is simple and easy to read.
- The irrigation system is cloud-based, allowing access anytime, from anywhere, using a mobile device or computer.
- If the homeowner isn’t available for certain time periods (e.g. vacation), he can authorize system access to others.
- The irrigation system can be run and monitored remotely by the irrigation contractor, who can make adjustments as needed.
- Statistical reports and charts are provided, which allow water usage tracking and better scheduling management.
- Alerts are sent to the homeowner in the event of system malfunctions. Alerts are also sent for scheduling changes (e.g. watering cancelled due to forecast showers).
- Wi-Fi smart controllers are now integrated into the “Internet of Things” (IoT). They work with digital assistants such as Alexa and Google Assistant so that the system or various zones can be started or stopped with a voice command.
- The irrigation system with a Wi-Fi controller is so efficient that busy homeowners don’t have to remember to make adjustments (e.g. change run times in the fall). They can leave the details to the experts — The controller.
Upgrading Your Smart Controller
You don’t need to buy a new controller to have a Wi-Fi-enabled irrigation system. If you own certain models of Rain Bird controllers, you can upgrade the current controller.
Different Types of Smart Controllers
Although not all controllers are Wi-Fi-enabled, there are still some pretty “smart” ones out there. Here is a general overview of the different kinds, including Wi-Fi controllers.
Basically, there are two categories of smart controllers: weather-based evapotranspiration, and soil moisture-based.
- Weather-Based Smart Irrigation Controllers
Weather-based controllers, also known as ET (evapotranspiration — loss of moisture in the landscape caused by evaporation from the soil and transpiration of moisture from plant leaves) controllers, adjust irrigation schedules using local weather data to ensure the landscape receives the appropriate amount of water.
The weather data is derived from calculations of temperature, solar radiation, wind speed, and relative humidity, and is usually expressed as the depth of water in inches, or the volume of water in gallons, used by a planted area for a day, week, month, or year. For example, in a hot, dry climate in July, the ET rate could be 0.25 inches per day — so 0.25 inches of water a day has to be replaced for your grass to stay green.
There are essentially three categories of weather-based ET controllers based on the type of weather data they use: historical, on-site, and signal-based.
Historic ET Controllers
These determine the amount of watering needed based on historical weather and water usage for your area. On some models you only have to enter the zip code for the controller to access the data from its memory. For other models you have to manually key in the historic data from a website or user’s manual.
The data usually resets monthly, and although not perfect, saves a significant amount of water. You may have to override the automatic control settings if the weather is unusual for the month (e.g. extremely hot).
Historic ET Controllers with a Sensor
These controllers use historical data to determine watering time, but then make up-to-the-minute, real-time adjustments using either a temperature or solar radiation sensor. The addition of the sensor allows for more efficient watering than just using the historical data alone.
Sensor-based controllers gather their information daily from the site and use it to adjust their irrigation schedule. The sensor hardware may include mini-weather stations, or weather sensors that monitor temperature, rainfall, solar radiation, or soil moisture. Many sensors are now wireless, which makes them easy to install.
Your current controller may not be able to integrate the sensor hardware, and you may have to replace it with a weather-based controller. However, some companies provide “add on” sensors and equipment that will upgrade your existing controller to a “smart” one that can work with the sensors.
Signal-based controllers use weather data from publicly available sources, or from weather station networks. The ET value is calculated for a hypothetical grass surface at the site, and the data is then sent via Internet, radio, paging networks, or a mobile device to update the current watering schedule at that site. Usually there’s an annual subscription fee for the service. Without an activated signal, signal-based controllers operate like a standard controller, and won’t make any automated scheduling adjustments.
- Soil Moisture-Based Controllers
These types use sensors to measure the actual moisture content of the soil to determine the watering schedule. The sensors are buried in the root zone of trees, turf, or shrubs, and transmit their readings to the controller. The system then compares this data to the recommended moisture level for the plant, soil type, and other information that was programmed into the controller when it was set up.
Moisture-based systems are available as integrated controllers and as add-on technology. Two different soil moisture systems are available:
- Suspended cycle irrigation systems, which use watering schedules with start times and duration. When there’s enough moisture in the soil, the system will stop the next scheduled irrigation
- Water on demand irrigation, which has no programmed duration — only start times and days of the week. The user sets lower and upper moisture thresholds, and the system starts and ends irrigation based on those levels
Are you interested in saving money with a smart controller? Call us at (512) 694-1147 or get in touch with us online. We’re the experts in sprinkler system design, installation, repair and maintenance.