Night Battle Against Frost – How Did We Act?

As soon as ground-level temperatures began to drop dangerously (reaching as low as 0.4°C on the night of May 5th to 6th!), we decided not to wait for all the automatic conditions to be fully met and manually started our main protection program "Sprinkling 2 sections" (PID 0) on the OpenSprinkler controller. This program, as configured, sequentially activated all 6 zones (3 minutes each) and thanks to the repeat settings in the controller itself (set to a large number of repetitions), this cycle continued for many hours.

The system ran continuously for most of both nights. We manually stopped it only in the morning of May 6th, when the ground-level temperature rose to a safer 2.7°C.

How Much Water Did We Use? "A Bit" Is an Understatement!

Our new logging system in Google Apps Script (thanks to the logDailySprinklerSummary function) meticulously tracked the sprinkler activity. The results are impressive and thought-provoking:

• Night of May 4th to 5th: Estimated water consumption was approximately 17,820 liters (17.82 m³).
• Night of May 5th to 6th: Similarly, we used approximately 17,820 liters (17.82 m³).

In total, over these two critical nights, approximately 35,640 liters of water went toward protecting the vineyard, which is over 35 cubic meters!

To put this amount into perspective:

• That's enough to fill approximately 30 standard garden hot tubs.
• It would be enough for over 190 full bathtub baths.
• It's still "only" about 1.4% of an Olympic swimming pool's capacity, but for a vineyard, it's truly a significant water investment.

Indeed, "quite a bit of water was used," which shows how resource-intensive and costly effective frost protection can be.

Conclusions

These nights were a valuable experience. They confirmed that:

• Manual intervention and starting the system "just in case" was the right decision, given the dynamics of temperature drops.
• The "Sprinkling 2 sections" program in OpenSprinkler, configured for multiple repetitions, works reliably, providing continuous protection after a single activation.
• Our Google Apps Script correctly monitors the situation and logs data, which now allows us to precisely analyze the course of events and resource consumption.
• Automatic start thresholds (especially the absolute 0.5°C threshold) are important, but vigilance and readiness for manual action still remain crucial.

We hope these were the last such cold nights this season. Keep your fingers crossed!