Temperature and Humidity: Difference between revisions

Revision as of 13:56, 16 February 2022

Temperature and humidity share a single article as they are so closely linked. Generally, humidity in a growing context refers to Relative Humidity (RH). As temperature decreases the amount of water vapour it can hold before it condenses back into a liquid decreases. In other words, hotter air can hold more water vapour per volume than cold air can^[1]. Temperature and humidity can also be used to calculate the Vapour pressure deficit (VPD) which provides an indication to the cultivar's capacity for gas exchange.

Ventilation

Ventilation is a very important part of having control over the temp and humidity. In other words, a fan is crucial. Blower (centrifugal fans) should be used for this type of ventilation^[2]

Vapour pressure deficit (VPD)

VPD is a metric 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).

An excellent VPD calculator and chart of ideal VPD for each life stage can be found at dimluxlighting.com

Ideal conditions

The ideal temperature is range is 24°- 28°C^[4] while the ideal humidity is 40-60%. Of course, the exact ideal values differ between life stages and different strains.

References

↑ https://www.royalqueenseeds.com/blog-indoor-cannabis-growing-relative-humidity-and-temperatures-n243
↑ Centrifugal Fan vs Axial Fan | Industrial Accessories Company - https://www.youtube.com/watch?v=gYxLbBP3evM
↑ L Breit, M Leavitt, A Boyd, Cannabis Science and Technology 2(2), 52-61 (2019). https://www.cannabissciencetech.com/view/circular-cannabis-systems-tracking-and-minimizing-waste-and-emissions-impacts
↑ Chandra et al. (2008) - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550641/pdf/12298_2008_Article_27.pdf

[1] ttps://www.royalqueenseeds.com/blog-indoor-cannabis-growing-relative-humidity-and-temperatures-n243

[2] Centrifugal Fan vs Axial Fan | Industrial Accessories Company - https://www.youtube.com/watch?v=gYxLbBP3evM

[3] L Breit, M Leavitt, A Boyd, Cannabis Science and Technology 2(2), 52-61 (2019). https://www.cannabissciencetech.com/view/circular-cannabis-systems-tracking-and-minimizing-waste-and-emissions-impacts

[4] Chandra et al. (2008) - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550641/pdf/12298_2008_Article_27.pdf

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-Temperature and humidity are paired together 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 it can hold before it condenses back into a liquid decreases. In other words, hotter air can hold more water vapour per volume than cold air can. The Temperature and humidity can also be used to calculate the Vapour pressure deficit (VPD) which provides a measure of how open the cultivar's [[Anatomy_of_Cannabis#Stomata|stomata]] are and it's capacity for [[Plant_processes#gas_exchange|gas exchange]]
+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 it can hold before it 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>. Temperature and humidity can also be used to calculate the Vapour pressure deficit (VPD) which provides an indication to the cultivar's capacity for [[Plant_processes#gas_exchange|gas exchange]].
-This article by [https://www.royalqueenseeds.com/blog-indoor-cannabis-growing-relative-humidity-and-temperatures-n243 Royal Queen Seeds] covers the physical relationship between temperature and humidity and the values that are best for the plant at each stage of growth.
 ==Ventilation ==
@@ Line 8: / Line 5: @@
 ==Vapour pressure deficit (VPD)==
-VPD is a metric to measure the difference between how much water there is in the air (AVP) and the maximum amount of water the air can currently hold (SVP).
+VPD is a metric 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).
-An excellent VPD calculator and chart can be found at [https://www.dimluxlighting.com/knowledge/vapor-pressure-deficit-vpd-calculator/ dimluxlighting.com]
+An excellent VPD calculator and chart of ideal VPD for each [[Life Stages|life stage]] can be found at [https://www.dimluxlighting.com/knowledge/vapor-pressure-deficit-vpd-calculator/ dimluxlighting.com]
 [https://www.cannabissciencetech.com/view/circular-cannabis-systems-tracking-and-minimizing-waste-and-emissions-impacts More on VPD]<ref>L Breit, M Leavitt, A Boyd, Cannabis Science and Technology 2(2), 52-61 (2019). https://www.cannabissciencetech.com/view/circular-cannabis-systems-tracking-and-minimizing-waste-and-emissions-impacts</ref>
 ==Ideal conditions==
-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%
+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%. Of course, the exact ideal values differ between life stages and different strains.
 == References ==