2 minute read
Tab. 3: Chamber settings
The mean CO2 amount was in average a bit higher in the LED treatment due to nearly 50 % more often open windows in the HPS chamber. The CO2 amount was in the LED chamber higher in the first three weeks of the growing period, while later in the growing period no differences between light sources were observed when week 8, 15 and 16 were excluded. In week 12 was the CO2 amount higher in the HPS treatment, while in week 13 was it the other way round.
The air temperature was in average 0,4 °C higher in the HPS chamber. This was due to a higher day temperature in the HPS chamber because of the HPS lamps generate high radiant heat. This difference between chambers was much smaller during the night.
The floor temperature was comparable between light sources during the day. However, during the night was the temperature higher in the HPS chamber than in the LED chamber.
Tab. 3: Chamber settings.
W ee k
CO2 (ppm)
HPS LED Air (day / night) (°C)
HPS LED Floor day / night (°C) HPS LED
1 497 527 13,0 (15,9 / 11,1) 12,5 (15,1 / 10,4) 34,8 / 23,5 34,9 / 21,3 2 460 487 16,4 (18,0 / 11,5) 15,2 (16,7 / 11,3) 34,8 / 28,0 34,9 / 26,2
3 433 470 15,0 (16,6 / 10,8) 14,5 (16,0 / 10,4) 34,8 / 20,9 34,9 / 17,3
4 727 723 14,9 (16,3 / 10,5) 14,2 (15,4 / 10,1) 34,8 / 19,9 34,9 / 17,2
5 712 724 16,2 (17,3 / 12,2) 15,5 (16,6 / 11,8) 34,8 / 21,9 34,9 / 18,9
6 728 741 16,0 (17,2 / 11,9) 15,4 (16,6 / 11,3) 34,8 / 21,8 34,9 / 18,8
7 540 527 15,7 (16,9 / 11,3) 15,0 (16,1 / 11,4) 34,8 / 21,7 34,9 / 19,2
8 649 736 15,9 (17,2 / 11,3) 15,5 (16,7 / 11,3) 34,8 / 21,5 34,9 / 19,1
9 696 729 15,9 (17,2 / 11,4) 15,5 (16,8 / 11,3) 34,8 / 21,5 34,9 / 19,1
10 744 757 15,5 (16,8 / 10,8) 15,0 (16,3 / 10,8) 34,8 / 21,3 34,9 / 18,5
11 682 713 16,0 (17,3 / 11,5) 15,6 (16,8 / 11,3) 34,8 / 21,6 34,9 / 18,9
12 717 681 16,5 (17,7 / 12,6) 16,1 (17,3 / 12,2) 34,8 / 22,7 34,9 / 19,9
13 678 735 15,7 (17,1 / 10,6) 15,4 (16,7 / 10,9) 34,8 / 21,8 34,9 / 18,9
14 710 722 15,5 (16,9 / 11,0) 15,2 (16,6 / 10,9) 34,8 / 21,3 34,9 / 18,5
15 578 636 16,6 (17,9 / 12,3) 16,3 (17,5 / 12,0) 34,8 / 20,5 34,9 / 18,4
16 637 16,0 (17,3 / 11,5) 34,9 / 17,8
17 645 15,9 (17,3 / 11,2) 35,1 / 17,7
