Brian420pm
Well-Known Member
Vapor Pressure Deficit (VPD) provides ideal temp/humidity pairs to maximize the health of your plants. In other words, if the temp goes up then humidity should also increase to maintain a better balance.
Once you settle on one Vapor Pressure Deficit (VPD) chart (yah many to choose from), then you pick the temp/humidity range you want. You'll get the hang of it after a few grows. I simplified and printed one chart and it's always handy for reference.
The science behind this is fascinating! It's all about what's happening within the millimeter of space above each leaf. There are ideal ranges depending on the difference between ambient humidity and leaf surface humidity! Fans blowing directly on your plants from above will measure a max humidity difference, while still air shows little to none.
Using any of the general charts will give you acceptable results, but more detail is out there, I encourage exploration!
Once you settle on one Vapor Pressure Deficit (VPD) chart (yah many to choose from), then you pick the temp/humidity range you want. You'll get the hang of it after a few grows. I simplified and printed one chart and it's always handy for reference.
Temp RH
73 52
74 53
75 54
76 55
77 57
78 59
79 60
80 61
81 62
82 65
83 66
84 66
85 67
73 52
74 53
75 54
76 55
77 57
78 59
79 60
80 61
81 62
82 65
83 66
84 66
85 67
The science behind this is fascinating! It's all about what's happening within the millimeter of space above each leaf. There are ideal ranges depending on the difference between ambient humidity and leaf surface humidity! Fans blowing directly on your plants from above will measure a max humidity difference, while still air shows little to none.
Using any of the general charts will give you acceptable results, but more detail is out there, I encourage exploration!