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TheBigyin

Need more humidity in veg!

25 posts in this topic
On 8/30/2018 at 11:37 PM, TheBigyin said:

Cheers bud, got a tray of water in there the now. But aye sounds a bit more practical. 

 

Cheers 

 

TB

 

Got a fan blowing over that? The air movement will help vaporise/evaporate the water and distribute it around the room/tent/whatever

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5 hours ago, Buckfacked said:

 

The air movement will help vaporise/evaporate the water and distribute it around the room/tent/whatever

 

Do you have any science/maths to back up this statement 

 

Because my understanding tells me it doesn’t work like that quite the opposite in fact when you consider pressures

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1 minute ago, Davey Jones said:

 

Do you have any science/maths to back up this statement 

 

Because my understanding tells me it doesn’t work like that quite the opposite in fact when you consider pressures

 

You blow air over the water, not at it, you create a low pressure above which will speed up evaporation, etc.

Very easy for you to test yourself, take two small pots of wet soil, have a fan blow over one of them, see which one dries out faster.

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@Buckfacked I don’t need to test anything mate I have worked with humidity extensively in my career and know a fair bit about it

 

Couple it with adsorption and it’s quite powerful 

 

I know lots of equations (there are over 40) and the theory of psychrometrics I have computer simulations surface plots and a lot of experience in the real world 

 

Blowing air will increase the local pressure, increasing the pressure increases relative humidity, the difference in moisture’s makes a potential exactly like a voltage/force 

 

Less moisture will evaporate into the surrounding air because there is less driving it 

 

It takes a fair bit of energy to change the phase of water, the triple point of water is really interesting when you look at the physics pressure and temperature it’s very technical

 

 Blowing air will do nothing to evaporate water, your experiment dries out quicker because of the sheer amount of air that’s passing as opposed to a static environment that reaches equiibrium and stays there it’s totally missing the whole theory altogether 

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4 hours ago, Davey Jones said:

@Buckfacked I don’t need to test anything mate I have worked with humidity extensively in my career and know a fair bit about it

 

Couple it with adsorption and it’s quite powerful 

 

I know lots of equations (there are over 40) and the theory of psychrometrics I have computer simulations surface plots and a lot of experience in the real world 

 

Blowing air will increase the local pressure, increasing the pressure increases relative humidity, the difference in moisture’s makes a potential exactly like a voltage/force 

 

Less moisture will evaporate into the surrounding air because there is less driving it 

 

It takes a fair bit of energy to change the phase of water, the triple point of water is really interesting when you look at the physics pressure and temperature it’s very technical

 

 Blowing air will do nothing to evaporate water, your experiment dries out quicker because of the sheer amount of air that’s passing as opposed to a static environment that reaches equiibrium and stays there it’s totally missing the whole theory altogether 

 

 

And when that pot dries quicker, explain where the water goes if it is not going into the air and circulating thanks to the airflow. Does it vanish into nothing like a Paul Daniels magic trick? Dos it go underground? Do aliens take it away? And if it doesn't do what I say then explain why my humidity meter registers an increase.

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I don’t really know why I am bothering with this conversation @Buckfacked It’s clear you think you have it all worked out and your arrogant attitude is appalling that’s not just this thread it’s actually limiting you from learning something to be honest 

 

I recommend you look at the water content of air vs RH and temperature, in a cubic meter of air fully saturated there’s something like 23 grams of water at 25c

 

The same air at 60%rh holds about 13grams 

 

10 grams of water isn’t a lot of volume that’s the theoretical maximum you can evaporate by blowing air at a bucket of water, it simply won’t increase your humidity by any amount that’s practical and in fact the increase in pressure makes it even worse, that’s why you don’t see a humidifier that works on moving air they use changes in pressure and temperature to do that. That’s what an air conditioner does compresses removes the heat then expands that way you can finely control all the parameters 

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You don't need pressures to explain mass transport from the liquid to the gas phase, it's a diffusion process. By which I mean that mass (in this case water vapour) flows from a region of high concentration (the water) to a region of low concentration (the air).

 

This will happen faster when the air is moving, because the thickness of the diffusion layer reduces.

 

Think of the wind drying out a puddle. The stronger the wind the faster the puddle disappears. Unless the air is saturated, in which case there is no driving force for diffusion, and hence no mass transport.

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2 minutes ago, Davey Jones said:

I don’t really know why I am bothering with this conversation @Buckfacked It’s clear you think you have it all worked out and your arrogant attitude is appalling that’s not just this thread it’s actually limiting you from learning something to be honest 

 

I recommend you look at the water content of air vs RH and temperature, in a cubic meter of air fully saturated there’s something like 23 grams of water at 25c

 

The same air at 60%rh holds about 13grams 

 

10 grams of water isn’t a lot of volume that’s the theoretical maximum you can evaporate by blowing air at a bucket of water, it simply won’t increase your humidity by any amount that’s practical and in fact the increase in pressure makes it even worse, that’s why you don’t see a humidifier that works on moving air they use changes in pressure and temperature to do that. That’s what an air conditioner does compresses removes the heat then expands that way you can finely control all the parameters 

 

 

I go by what I see with my own eyes, you have a problem with that then that's not my problem for a clear difference has been seen and that trumps "theory".

But you keep it coming, at least I offered a solution instead of bitching about what someone said. 

 

Oh, and I know how HVAC works, I spent years repairing the buggers and that includes the dehumidifying and humidifying parts. So please don't try to lecture me when actual hands on experience has shown me something that does have an effect.

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On 12/09/2018 at 11:20 AM, Davey Jones said:

@Buckfacked

 Blowing air will do nothing to evaporate water, your experiment dries out quicker because of the sheer amount of air that’s passing as opposed to a static environment that reaches equiibrium and stays there it’s totally missing the whole theory altogether 

Sorry, won't it depend on prevailing RH?

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