@naamang Look, I’m not debating to prove that I’m correct or that you are wrong. In fact, my knowledge of sprinklers/irrigation systems is just about average. I’m a homeowner that is interested in maximizing the efficiency of my home sprinkler system. I agree that the marketing verbiage is somewhat misleading, I was also under the impression that the duration of watering would somehow be regulated by the flow meter. But it doesn’t bother me. What is marketing if it doesn’t include a bit of hyperbole?
However, I’m not sure one can achieve the level of accuracy you seek. BTW, what level of accuracy is sufficient for you? 90%? 95%? All I’m saying is that most installations with typical average nozzles, valves, conduits, etc. will have that much variation.
- Are you saying that if the pressure at one nozzle falls by say, 5-10%, the radius/volume of water output will not change? If the throw (radius) changes, then so does amount of water per area, right?
- Again, I’m not sure the soil type data I have is correct, unless I have soil tested. I’m assuming its correct. I don’t know if the developer trucked in soil from 10miles away or 50 miles away or not at all. But this is a minor factor.
- I understand throw is configurable, but installers don’t use a ruler to determine placement of heads to within a few inches. At least mine didn’t. I have one area of my yard that gets sprayed by nozzles from 3 different zones. These nozzles have different throws. Although calibrated at the factory to be identical, in the 15 years since they were installed, I can see that the spray pattern has changed. But not enough for me to tweak them or worry about changing them. So I cannot determine how much water this one area gets with 100% accuracy. I’d have to probably do a 100 cup catch test for an hour or more to get a reasonable average value.
3a. So how do I calculate “area”? Its not a rectangle, but a mish-mash of full 360 degree arcs, some 1/2 arcs and some 3/4 arcs. The rotors don’t rotate with exact precision. One seems to be slower than the others. I’m not sure about you, but calculating the area of several overlapping somewhat circular shapes is not easy. In fact, I’d say its a significant challenge.
- Agree about “hyper local intelligence…” being misleading. Its their best guesstimate based on data supplied by a 3rd party. That’s their out.
- And other factors that I don’t know but can guess (wind, evaporation etc).
Above all, if the flow rate changes between calibration and actual run or during a run, its just not easy to adjust watering time on the fly. I’m sure you appreciate that. The software loop to do that calculation will be complicated and prone to error.
I’m sure these factors contribute to at least 10% deviation from a theoretical calculation. I can live with that. The reasons I’m appreciative Rachio are that it gives me better insight into what is going on, the ability to turn on/off a sprinkler by standing near it and not running back and forth into my garage and the potential that the software can get better. And the software/hardware look pretty modern. There was not another system that seemed to deliver these (subjective) factors, so I went with the system and am pretty satisfied with it.
OTOH, I am confused by what “Flex Daily” actually does. I entered certain watering times for 3 zones when configuring them and I notice they changed for up-coming sessions. So how did the algorithm calculate the changes? If it did it on parameters like % of soil dryness (or whatever the technical term is), surely, to your point, it can calculate amount of water required for a certain area and flow to achieve a watering target. I’m assuming you want to set all the parameters (soil type, slope, sunlight, all the parameters in the “advanced” tab), plus flow rate per zone, set a target watering level, maybe limit days on which to water and presto! the algorithm calculates watering times based on these plus weather intelligence parameters. At least that’s how I would do it. Don’t know what Rachio does. Is there a complete technical explanation somewhere that I missed?
I’m a physicist and engineer with significant software experience (own an app business with a s/w dev team), so feel free to geek out on me.