Temperature and Humidity: Difference between revisions

Temperature and humidity share a single article as they are so closely linked. Generally, humidity in a growing context refers to [https://en.wikipedia.org/wiki/Humidity Relative Humidity] (RH). As temperature decreases, the amount of water vapour itthe air can hold before itthe water condenses back into a liquid, decreases. In other words, hotter air can hold more water vapour per volume than cold air can<ref>https://www.royalqueenseeds.com/blog-indoor-cannabis-growing-relative-humidity-and-temperatures-n243</ref>. TemperatureTo andreiterate humidityin cananother alsoway, beit usedis possible to calculatelower thehumidity Vapourby pressurewarming deficitup (VPD)the whichair. providesAll an indicationdue to the cultivar'srelationship capacitybetween fortemperature [[Plant_processes#gas_exchange|gasand exchange]]humidity.

VentilationIn isIndoor agrows, veryventilation importantis partthe ofmost havingeffective controlway overof influencing the temp and humidity of the environment. As the plant expels water vapour via [[Plant processes#Transpiration|transpiration]] the air becomes more humid and this excess water vapour must be removed from the growing environment. In other words, a fan to remove humid air is crucial. Blower (centrifugal fans) should be used for this type of ventilation<ref>Centrifugal Fan vs Axial Fan | Industrial Accessories Company - https://www.youtube.com/watch?v=gYxLbBP3evM </ref>. To control the smell emitted from the plant, [[Carbon filter|carbon filters]] are often implemented as part of the exhaust of the ventilation.

VPD is a metric (unit kPa) used to measure the difference (deficit) between how much water there is in the air (AVP) and the maximum amount of water the air can currently hold (SVP). It is a more accurate way of measuring the "dryness" of air that takes into account air temperature, leaf temperature and air humidity. VPD directly correlates to rate of [[Plant processes#Transpiration|transpiration]]. Cannabis should be exposed to between 0.5 and 1.6kPa. Fluctuations in VPD over 0.5kPa can decrease yields by up to 20%. <ref>Minimizing VPD Fluctuations Maintains Higher Stomatal Conductance and Photosynthesis, Resulting in Improvement of Plant Growth in Lettuce, 2021 Inoue - https://doi.org/10.3389/fpls.2021.646144</ref>

The ideal temperature is range is 24°- 28°C<ref>Chandra et al. (2008) - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550641/pdf/12298_2008_Article_27.pdf</ref> while the ideal humidity is 40-60%. OfIdeal course,VPD theis exactaround ideal1 valueskPa differ<ref>Nadia Sabeh​​, dependingPhD on- theVapor currentPressure lifeDeficit stages(VPD) orand theCannabis plant'sCultivation [[genetics]].-