The 24-hour temperature strategy is not yet being applied by all Priva Connext users, but for both vegetable and ornamental cultivation it really is a control module that makes it easier to achieve production or planning objectives.
During the day there are circumstances that you cannot avoid as a grower, such as radiation, lighting that comes on, or perhaps a rain shower. This can cause the greenhouse temperature to deviate from the desired 24-hour temperature. To achieve the desired 24-hour temperature, it is necessary to compensate at other times of the day.
Ornamental plant cultivation
In ornamental plant cultivation we see that growers like to have control over the cultivation period. The daily temperature determines this to a large extent. With the 24/7 temperature strategy it is possible to set the average temperature over a 24-hour period.
In the 24-hour temperature strategy screen in Priva Office, the temperature range within which the control can compensate can be set for each period. After a deviation, the control fully automatically distributes the compensation over the remaining hours of the 24-hour period. An example: if there are five hours left in the 24-hour period and there is a deviation of 1 degree from the 24-hour temperature, compensation will be made at 0.2 degrees per hour. Martin van der Mei, gerbera cultivation consultant, endorses the benefit of the scheme:
"On gerbera farms, this control module is widely used. Virtually all gerbera growers have a PAR meter. Consultancy company Flori Consult Group has developed a table for gerbera cultivation from which the optimal 24-hour temperature can be extracted that corresponds to a certain PAR sum and daily CO2 value. This is how a gerbera grower knows how to keep his crop in balance."
- Martin van der Mei, consultant at Flori Consult Group.
The image below illustrates how the 24-hour temperature strategy works. In this situation at a gerbera grower, the 24-hour temperature depends on the radiation sum. With a higher radiation sum, a higher 24-hour temperature is therefore calculated. This is clearly visible in the example. The second day is a lighter day, with a higher radiation sum.
The 24-hour period starts at 06:00. It can be clearly seen that the actual 24-hour temperature (light green line) meets the calculated 24-hour temperature (dark blue line) at the end of the 24-hour period.
The red and the light blue line are the corrections made by the 24-hour temperature control to the heating temperature and the ventilation temperature. These values are adjusted to ensure that at the end of the 24-hour period the calculated 24-hour temperature is achieved.