1. Certifications
1.1. Irrigation
1.1.1. Certified Irrigation Contractor (CIC) Certified Irrigation Designer (CID) Certified Landscape Irrigation Auditor (CLIA) Certified Golf Irrigation Auditor (CGIA) Certified Landscape Water Manager (CLWM) Certified Agricultural Irrigation Specialist (CAIS) Certified Irrigation Technician (CIT)
1.2. EPA WaterSense program
2. Scientific Studies
2.1. Landscape irrigation by evapotranspiration-based irrigation controllers under dry conditions in Southwest Florida (http://www.sciencedirect.com/science/article/pii/S0378377409002340)
2.1.1. The ET controllers averaged 43% water savings compared to a time-based treatment without a rain sensor and were about twice as effective and reducing irrigation compared to a rain sensor alone.
2.2. Irrigation scheduling performance by evapotranspiration-based controllers (http://www.sciencedirect.com/science/article/pii/S0378377410002374)
2.2.1. It was found that all treatments applied less irrigation than required for all seasons.
2.2.2. the ET controllers applied only half of the irrigation calculated for the theoretical requirement for each irrigation event, on average.
2.3. EFFECTIVENESS OF SMART CONTROLLERS FOR WATER CONSERVATION IN RESIDENTIAL IRRIGATION (http://ufdcimages.uflib.ufl.edu/UF/E0/04/65/03/00001/DAVIS_S.pdf)
2.3.1. Proper controller programming was essential to achieving maximum water savings while maintaining acceptable landscape quality.
2.4. Smart Irrigation Controllers: Programming Guidelines for Evapotranspiration-Based Irrigation Controllers (http://edis.ifas.ufl.edu/pdffiles/AE/AE44500.pdf)
2.4.1. these controllers cannot fix a poorly designed or poorly maintained irrigation system. Thus, it is important to have the irrigation system inspected regularly and to have necessary maintenance performed in a timely manner.
2.4.2. While these controllers can be programmed once and left alone, they need maintenance to ensure that the signal is not lost and they are working properly
3. Issues with current controlers
3.1. Internet, fee based and other weather services cannot be accurate for rainfall amounts over a couple of hundred feet-such services/controllers would have received the same weather info and thus be totally wrong for one of the homes.
3.1.1. the incorporation of site specific rainfall measurements is extremely important to their success at managing landscape water needs and at a minimum a rain sensor should be used
3.2. the biggest problem is undetected system problems (leaks, out-of-adjustment sprinkler heads and other application devices, etc.).
3.3. the controller losing its programming (often meaning it defaults to the factory-set default which is to apply usually over-irrigate)
3.4. changes in landscape over time which dictate changes in irrigation amounts applied
3.5. landscape services who mismanage (or don’t manage) the efficiency and operation of the irrigation system and its controller.
3.6. controllers with on-site sensors appeared to fare better, adjusting irrigation during the extreme drought by factoring in harsher temperatures, decreased humidity, lower rainfall, and increased wind speeds.
3.6.1. The only downside with the onsite ET sensors is they will require periodic cleaning and they will eventually wear out and they are not cheap to replace.
3.7. WeatherTrak--like any controller--will not perform to its potential savings if the person controlling the controller does not understand the concepts and principles under which WeatherTrak operates
3.7.1. The issue with irrigation controllers not saving water, in general, is the absence of someone who is willing and able to run, monitor and adjust the controller. Often, this task is left to the very-busy landscape owner/manager or uneducated landscape service
3.8. Devices that used off-site sensors, however, relied on average measurements and weren’t always able to adjust watering needs accurately.
4. Patents
4.1. Smart Irrigation Assistant (http://www.google.com/patents/US20140117108)
4.2. Evapotranspiration forecasting irrigation control system (http://www.google.com/patents/US5696671)
4.3. System and method for use in controlling irrigation and compensating for rain (http://www.google.com/patents/US7229026)
4.4. Method and system for providing offset to computed evapotranspiration values (http://www.google.com/patents/US7305280)
4.5. System and method for systematically irrigating subregions of an irrigation region (http://www.google.com/patents/US7349763)
4.6. Calculating an ET value for an irrigation area (http://www.google.com/patents/US7430458)
4.7. Irrigation timer for adjusting watering time based on temperature and humidity change (http://www.google.com/patents/US7769494)
5. Existing Technologies
5.1. Weather-Based Controllers (http://www.irrigation.org/weather-based_controllers/)
5.1.1. *Alex-Tronix Universal Smart Module *Alex-Tronix Enercon Plus *Alex-Tronix Smart Clock *Aqua Conserve Aqua ET-9 *Calsense ET2000e *Cyber-Rain XCI *DIG Leit 2 ET *ETwater Smart Controller *ETwater Hermit Crab *Hunter ET System *Hunter Solar Sync Module * Hunter Solar Sync Sensor * Hydrosaver ETIC * Irritrol KwikDial Climate Logic * Irritrol MC48E Climate Logic * Irritrol RainDial Climate Logic * Irritrol Smart Dial * Irritrol Total Control Climate Logic * Motorola IRRInet-ACE * Motorola IRRInet-M *NDS Raindrip WeatherSmartPro *Rain Bird ESP-LX with ET Manager Cartridge * Rain Bird ESP-SMT *Rain Bird ET Manager * Rain Bird SST Smart Controller *Rain Master RME Eagle * Rain Master RME Eagle Plus *SMG Superior Control Sterling 8 * Toro EC-XTRA w Smart Pod * Toro Intelli-Sense * Toro TMC-212 Climate Logic * Toro TMC-424E-ID Climate Logic Kit *Tucor RKS with Tipping Rain Bucket * Tucor RKD-WS * WaterOptimizer *Weathermatic SL1600 * WeatherTRAK
6. Definitions
6.1. Smart Irrigation
6.1.1. use an array of sensors to determine just how much water is needed and when, conserving water
6.2. Smart controllers measure
6.2.1. water loss due to evapotranspiration (ET)
6.2.2. rainfall
6.2.3. temperature
6.2.4. solar radiation
6.2.5. relative humidity
6.3. Sensors types
6.3.1. Off-site
6.3.1.1. Relied on average measurements and weren’t always able to adjust watering needs accurately
6.3.1.2. Internet, fee based and other weather services cannot be accurate for rainfall amounts over a couple of hundred feet-such services/controllers would have received the same weather info and thus be totally wrong for one of the homes
6.3.2. On-site
6.3.2.1. Better, adjusting irrigation during the extreme drought by factoring in harsher temperatures, decreased humidity, lower rainfall, and increased wind speeds.
6.3.2.2. They will require periodic cleaning and they will eventually wear out and they are not cheap to replace. Have to clean it every couple of months because of all the fine dirt and debris blown in from wind settling inside the sensor.
6.4. Smart Controlers
6.4.1. Historic ET
6.4.1.1. Uses historical ET data from data stored in the controller
6.4.2. Sensor-Based
6.4.2.1. Uses one or more sensors (usually temperature and/or solar radiation) to adjust or to calculate ETo using an approximate method
6.4.3. ET
6.4.3.1. Evapotranspiration is the movement of water into the atmosphere from soil and vegetation.
6.4.3.2. Real-time ETo (usually determined using a form of the Penman equation) is transmitted to the controller daily. Alternatively, the runtimes are calculated centrally based on ETo and then transmitted to the controller.
6.4.4. On-Site Weather Station (Central Control)
6.4.4.1. Controller or a computer which is connected to an on-site weather station equipped with senors that record temperature, relative humidity (or dew point temperature) wind speed and solar radiation for use in calculating ETo with a form of the Penman equation