hey, sorry i was silent, crazy week, i only eat, work and sleep and read other forums about some advanced techinques... no, it should not give this results, i calculated RH via Javascript console on my browser, and it says RH at temps of 25 C and vpdSet of 1.61 is 49.19... i cant use my esp32 at the moment, it seems my drivers for usb on my laptop went crazy and i cant upload any sketch to arduino or esp32... ill try to make my old computer work for the weekend... but i did find error in my formula, which i corrected...1.61 VPD is too much, your plants will transpire (drink and breathe out) more water than usual, which may make them intake too much nutrients, and may lead to nutrient burn... VPD changes from stage to stage, check the charts (if they are hard to read for you, you can download this one:
https://github.com/plant-og/vpd and open index.html and choose stage of plant you want), and find your values... you can take lets say 26C and 22C for day/night temperatures, check the charts for RH (for veg its 65% - 70%), and hardcode those 4 values in your arduino for controlling your devices depending on what part of day it is for plants (lights on means day, lights off means night...
You used leafTemp = airTemp in your formula. If I set the vpdSet according to stage and use the time to determine day/ night then I can rerun rhSet for all my grows.
2020-09-01 03:17:39 INFO Temp=25.1*C Humidity=58.8% 54.5%=rhSet SVP hPa leaf=3.19 SVP hPa air=3.19 vpdSet=1.45
2020-09-01 03:19:37 INFO Temp=24.8*C Humidity=59.9% 53.7%=rhSet SVP hPa leaf=3.13 SVP hPa air=3.13 vpdSet=1.45
2020-09-01 03:22:33 INFO Temp=24.5*C Humidity=61.0% 52.9%=rhSet SVP hPa leaf=3.08 SVP hPa air=3.08 vpdSet=1.45
2020-09-01 03:26:30 INFO Temp=24.3*C Humidity=62.1% 52.3%=rhSet SVP hPa leaf=3.04 SVP hPa air=3.04 vpdSet=1.45
2020-09-01 03:26:57 INFO Temp=24.2*C Humidity=62.0% 52.0%=rhSet SVP hPa leaf=3.02 SVP hPa air=3.02 vpdSet=1.45
2020-09-01 03:35:30 INFO Temp=24.0*C Humidity=63.2% 51.4%=rhSet SVP hPa leaf=2.98 SVP hPa air=2.98 vpdSet=1.45
2020-09-01 03:50:22 INFO Temp=23.7*C Humidity=64.3% 50.5%=rhSet SVP hPa leaf=2.93 SVP hPa air=2.93 vpdSet=1.45
2020-09-01 04:22:45 INFO Temp=23.4*C Humidity=65.4% 49.6%=rhSet SVP hPa leaf=2.88 SVP hPa air=2.88 vpdSet=1.45
2020-09-01 05:04:17 INFO Temp=23.1*C Humidity=65.9% 48.7%=rhSet SVP hPa leaf=2.83 SVP hPa air=2.83 vpdSet=1.45
2020-09-01 05:54:42 INFO Temp=23.0*C Humidity=66.5% 48.4%=rhSet SVP hPa leaf=2.81 SVP hPa air=2.81 vpdSet=1.45
2020-09-01 08:18:23 INFO Temp=22.7*C Humidity=67.6% 47.4%=rhSet SVP hPa leaf=2.76 SVP hPa air=2.76 vpdSet=1.45
2020-09-01 09:05:36 INFO Temp=23.0*C Humidity=66.5% 48.4%=rhSet SVP hPa leaf=2.81 SVP hPa air=2.81 vpdSet=1.45
2020-09-01 09:11:16 INFO Temp=23.3*C Humidity=65.4% 49.3%=rhSet SVP hPa leaf=2.86 SVP hPa air=2.86 vpdSet=1.45
2020-09-01 09:12:27 INFO Temp=23.6*C Humidity=64.3% 50.2%=rhSet SVP hPa leaf=2.91 SVP hPa air=2.91 vpdSet=1.45
2020-09-01 09:13:41 INFO Temp=23.8*C Humidity=63.3% 50.8%=rhSet SVP hPa leaf=2.95 SVP hPa air=2.95 vpdSet=1.45
2020-09-01 09:15:28 INFO Temp=24.0*C Humidity=62.2% 51.4%=rhSet SVP hPa leaf=2.98 SVP hPa air=2.98 vpdSet=1.45
2020-09-01 09:16:31 INFO Temp=24.2*C Humidity=61.9% 52.0%=rhSet SVP hPa leaf=3.02 SVP hPa air=3.02 vpdSet=1.45
2020-09-01 09:18:25 INFO Temp=24.2*C Humidity=61.1% 52.0%=rhSet SVP hPa leaf=3.02 SVP hPa air=3.02 vpdSet=1.45
2020-09-01 09:26:19 INFO Temp=24.6*C Humidity=60.0% 53.1%=rhSet SVP hPa leaf=3.09 SVP hPa air=3.09 vpdSet=1.45
2020-09-01 09:44:53 INFO Temp=24.9*C Humidity=58.9% 54.0%=rhSet SVP hPa leaf=3.15 SVP hPa air=3.15 vpdSet=1.45
2020-09-01 10:24:32 INFO Temp=25.3*C Humidity=58.2% 53.1%=rhSet SVP hPa leaf=3.23 SVP hPa air=3.23 vpdSet=1.512
2020-09-01 10:33:10 INFO Temp=25.3*C Humidity=57.8% 53.1%=rhSet SVP hPa leaf=3.23 SVP hPa air=3.23 vpdSet=1.512
2020-09-01 11:19:03 INFO Temp=25.6*C Humidity=56.7% 54.0%=rhSet SVP hPa leaf=3.28 SVP hPa air=3.28 vpdSet=1.512
2020-09-01 11:43:54 INFO Temp=25.5*C Humidity=57.8% 53.7%=rhSet SVP hPa leaf=3.26 SVP hPa air=3.26 vpdSet=1.512
2020-09-01 12:44:31 INFO Temp=25.8*C Humidity=56.7% 54.5%=rhSet SVP hPa leaf=3.32 SVP hPa air=3.32 vpdSet=1.512
2020-09-01 14:36:17 INFO Temp=26.4*C Humidity=56.3% 56.1%=rhSet SVP hPa leaf=3.44 SVP hPa air=3.44 vpdSet=1.512
2020-09-01 15:15:13 INFO Temp=26.4*C Humidity=55.6% 56.1%=rhSet SVP hPa leaf=3.44 SVP hPa air=3.44 vpdSet=1.512
2020-09-01 15:26:44 INFO Temp=26.3*C Humidity=56.7% 55.8%=rhSet SVP hPa leaf=3.42 SVP hPa air=3.42 vpdSet=1.512
2020-09-01 15:36:13 INFO Temp=26.3*C Humidity=76.9% 55.8%=rhSet SVP hPa leaf=3.42 SVP hPa air=3.42 vpdSet=1.512
2020-09-01 15:36:19 INFO Temp=26.3*C Humidity=56.3% 55.8%=rhSet SVP hPa leaf=3.42 SVP hPa air=3.42 vpdSet=1.512
2020-09-01 15:46:57 INFO Temp=26.3*C Humidity=58.0% 55.8%=rhSet SVP hPa leaf=3.42 SVP hPa air=3.42 vpdSet=1.512
2020-09-01 15:47:08 INFO Temp=26.3*C Humidity=56.4% 55.8%=rhSet SVP hPa leaf=3.42 SVP hPa air=3.42 vpdSet=1.512
2020-09-01 15:49:12 INFO Temp=26.3*C Humidity=57.9% 55.8%=rhSet SVP hPa leaf=3.42 SVP hPa air=3.42 vpdSet=1.512
2020-09-01 15:49:17 INFO Temp=26.4*C Humidity=60.9% 56.1%=rhSet SVP hPa leaf=3.44 SVP hPa air=3.44 vpdSet=1.512
2020-09-01 15:49:41 INFO Temp=27.2*C Humidity=58.6% 58.1%=rhSet SVP hPa leaf=3.61 SVP hPa air=3.61 vpdSet=1.512
2020-09-01 15:49:51 INFO Temp=26.3*C Humidity=56.7% 55.8%=rhSet SVP hPa leaf=3.42 SVP hPa air=3.42 vpdSet=1.512
2020-09-01 15:51:49 INFO Temp=26.4*C Humidity=58.2% 56.1%=rhSet SVP hPa leaf=3.44 SVP hPa air=3.44 vpdSet=1.512
2020-09-01 15:51:54 INFO Temp=26.4*C Humidity=59.6% 56.1%=rhSet SVP hPa leaf=3.44 SVP hPa air=3.44 vpdSet=1.512
2020-09-01 15:52:05 INFO Temp=26.3*C Humidity=56.5% 55.8%=rhSet SVP hPa leaf=3.42 SVP hPa air=3.42 vpdSet=1.512
2020-09-01 16:27:57 INFO Temp=26.4*C Humidity=56.9% 56.1%=rhSet SVP hPa leaf=3.44 SVP hPa air=3.44 vpdSet=1.512
2020-09-01 23:56:59 INFO Temp=25.8*C Humidity=46.9% 54.5%=rhSet SVP hPa leaf=3.32 SVP hPa air=3.32 vpdSet=1.512