Irrigation system for a large (still) empty plot

Hello Denz,

what kind of soil do you have? Lawn requires about 15-20 liters per week during dryness.
That gets you to 42m3/week.
Yes, that is a lot but in practice it will be less due to rainfall, dew, etc.
It also depends on your expectations. Do you want to fertilize, aerate regularly...? Or should it just be "green"?
You have a large property. At least you can supply from a well and not from the tap.
There is a reason why we install a 76m3 cistern
But your rough calculation is about right.

So here is my current status:


[ATTACH alt="Unbenannt.png" type="full"]43415[/ATTACH]


At each sprinkler position, I have always written down the (expected) flow rates.
In addition, I have drawn the main lines in light green and numbered the positions of the valve boxes from 1-4.


Where I am still uncertain is at the bottom right by the shrub group. The sprinklers basically water the shrubs as well. Can this be done like this? Or should I water them separately and then redesign the sprinkler at the corner of the house?


I have summarized the zones in such a way that it makes sense to me:


[ATTACH alt="Unbenannt2.png" type="full"]43416[/ATTACH]

I have a maximum flow rate of 27.6 l/min (=1.66 m³/h) in one zone.


According to the characteristic curves, I understand it like this: I have 2 m³/h available at a delivery height of 54 m. My pump is set to 15 m and the elevation difference on the property is 1 m – so 16 m total. Leaves 38 m. So 3.8 bar. I need 2.8 bar at the sprinklers. That leaves 1 bar buffer for pipe losses.
(If I select "Input" under "Operating point" at the top right and enter 1.7 m³/h for Q and 16 m for H, the diagram even gives me a delivery volume of 2.7 m³/h at 40.4 m.)


With DN32, you have about 0.25 bar pressure loss over 50 m at 2 m³/h. T-pieces 0.01 bar and 90° bends 0.002 bar. The Hunter valve has a 0.1 bar pressure loss. So I have a maximum of 0.4 bar pressure loss in the main line. If I also do the further distribution in DN32, I should easily manage with the remaining 0.6 bar buffer.


Regarding irrigation controller:
I now have 16 zones including 3 water cans. I planned valve boxes with a total of 20 valves to still have a buffer for possible expansions.
With Hunter, it works by stations, whereby one station equals one valve, if I understood correctly.
So I would need, for example, the "Hunter Wi-Fi controller PRO-HC-2401 ie". This can control 24 stations and costs about €730.
Plus rain sensor for about €80. So about €810.
For control via KNX I need a switching actuator approx. €350 and a 24 VAC transformer approx. €50 and a KNX rain sensor approx. €110. So €510.
If I assume that I do the logic via Edomi, I have a price advantage of €300 if I do it via KNX, or have I overlooked something here?
But I would have the advantage of opening 2 zones simultaneously. That makes sense to me since I have very small zones. For example, for the hedges. I could then run those together. Or if I water something manually, i.e., use one of the water cans, a small zone could additionally be activated so that the pump doesn't constantly turn on and off. (Well, for that I would then need a pressure sensor)


Regards denz

The planning is good. A garden changes over time and sprinklers are not like lasers. You have a few small holes in the cover. However, due to the adjustment of the sprinklers, they should not matter. For the hedges, I would leave it as it is as long as they are not particularly sensitive plants. Also good is the planning of the reserve. Water valves could, in the worst case, be connected together. You only take from one. In your case, due to the distribution, this is probably not sensible. Do you need the controller as an outdoor version? Why a rain sensor? Weather station with KNX is already available, isn't it? The last Hydrawise systems I installed were without rain sensors. The weather data from local weather stations (partly private) are sufficient. Adjustments with temperature, wind, forecast, etc. fit very well. If you have two small zones, you can run them together. The water valve idea will not work. As soon as you connect a hose there, the pressure will drop and there will be a lack of volume. The sprinklers will partly retract or at least no longer rotate... In your case, KNX is cheaper (not considering the rest of the infrastructure). But it is significantly less convenient when it comes to quick adjustments. The app and website are easy to use. If you are away for a longer time, it must also be operable by other persons in the house. The goal is indeed automation but I don't know if there are good irrigation modules in edomi or if you can cover all eventualities with your own programming. Ultimately, it is a question of price, playfulness, and usefulness. The version with KNX is easier to link with the robotic mower... I know both variants. For us it will also be KNX. For those who want a "simple" solution, I would recommend Hydrawise.

Assuming that the 2m³ at 54m delivery height is correct, so in my case (after 16m delivery height/well depth) still 3.8 bar present, I would now go ahead and get the PE pipe for the main lines - so 32mm (1") PE pipe. After the valve boxes, 1/2" should probably be sufficient, right? 16 bar pressure resistance?

Regarding the valves. Finished valve boxes are available from various suppliers. So far, I have seen them with the PGV valve. But wouldn't the PGV JAR Top be more sensible?

PS: I noticed that the water dials actually wouldn't need a valve in front of them, right?

1/2” after the valve is theoretically sufficient if the circuit is not that large. I would rather continue with 1”. Only one type of pipe, one size of fittings... of course a bit more expensive. The normal PVG valves are sufficient. The PVG Jar Top valves are more maintenance-friendly but also more expensive. I prefer to replace the entire valve if it breaks after 5-10 years...

Ok. I was just confused because the regular ones have a flow rate of 5 to 34m3 and the JAR Top 0.05 to 9m3.