Best place to mount dehumidifier?

[CptnFeatherswrd]

Hey guys.
Im building a new cab atm and just wondering where I should mount the dehumidifier for best results?
I have outside air ducted in to the lower lh side and the exhaust is on the upper rh side. So cross flow, bottom to top.
Would it be beneficial to put the dehumidifier so it gets a direct feed of the incoming moist air?
Or is it better off up high where the air is hotter?

 

[Mikell]

How large is the cabinet?

I prefer to hang up high. Drainage, better efficiency (I am unsure why) and an uncluttered floor.

If the cabinet is smaller and in a closed room, I would treat it like a lung room. But that's a different set up. Inline with intake?

 

[CptnFeatherswrd]

Cabinet is 5x3 and 4 feet high.

 

[Douglas.Curtis]

If the cabinet is smaller and in a closed room, I would treat it like a lung room. But that's a different set up. Inline with intake?

This is what I would do as well.

Dehumid and cool the room your box is in.

 

[Drop That Sound]

I just built a L5.5 x W3.25 x H3.25 veg cab which is about the same.

On the intake end, just (thinking..) outside the box, i'm setting up a duct contraption that lets air flow through either a humidifier, dehumidifier, or straight from the lung room. Will have an arrangement of different things like filters to plug in to the main porthole as well.

On the exhaust end, the fan blows to a Y and either out a dedicated dryer duct, or a thermostat controlled motorized damper that opens up and cycles some of the air back around to the lung room for the wintertime. Currently planning to build and duct in a dual core heat recovery ventilator as well

Anyways ya like Mikell said if your in a smaller room you could just run it next to the cab intake, especially if your exhaust go's elsewhere. Otherwise you could just tape some duct fittings on the intake and exhaust vents on the dehuey and crossflow it through 2 more ports. No need to have it inside that way!

 

[Drop That Sound]

P.S. Those portable AC 5 inch hoses, that can bend to any shape and stay work awesome, on the inside of smaller rooms. You can send air anywhere you want real easy. Otherwise they scrunch back up from like 10 feet to 2. hooked to a dehuey would be great, in any situation you could setup the I/E on either side of the room, which is way more effecient than just sitting in there..

 

[CptnFeatherswrd]

P.S. Those portable AC 5 inch hoses, that can bend to any shape and stay work awesome, on the inside of smaller rooms. You can send air anywhere you want real easy. Otherwise they scrunch back up from like 10 feet to 2. hooked to a dehuey would be great, in any situation you could setup the I/E on either side of the room, which is way more effecient than just sitting in there..

You mean force feed it? No air gets in without passing through the dehumidifier?

 

[CptnFeatherswrd]

This is what I would do as well.

Dehumid and cool the room your box is in.

Unfortunately its not in a closed room, it breathes and vents to outside air

 

[paladin420]

In Private?

 

[CptnFeatherswrd]

In Private?

Very discrete

 

[Douglas.Curtis]

Unfortunately its not in a closed room, it breathes and vents to outside air

Then what air were you intending to dehumidify? Dehueys are for sealed rooms, not active air.

 

[Mikell]

I just built a L5.5 x W3.25 x H3.25 veg cab which is about the same.

On the intake end, just (thinking..) outside the box, i'm setting up a duct contraption that lets air flow through either a humidifier, dehumidifier, or straight from the lung room. Will have an arrangement of different things like filters to plug in to the main porthole as well.

On the exhaust end, the fan blows to a Y and either out a dedicated dryer duct, or a thermostat controlled motorized damper that opens up and cycles some of the air back around to the lung room for the wintertime. Currently planning to build and duct in a dual core heat recovery ventilator as well

Anyways ya like Mikell said if your in a smaller room you could just run it next to the cab intake, especially if your exhaust go's elsewhere. Otherwise you could just tape some duct fittings on the intake and exhaust vents on the dehuey and crossflow it through 2 more ports. No need to have it inside that way!

Hyuup.

 

[Drop That Sound]

Yeah you could install it inline with the intake, to control the incoming air. Dehumidifiers still work in a passive room, just don't run as effectively and alot more often..

What ever way you set it up, if you stay with outside intake & exhaust, I'd recommend going with a good day and night fan speed controller like this http://www.titancontrols.net/products/ventilation/mercury-4.aspx... that lets you set the idle speeds and setpoints.

That way when the lights go off, the fan either shuts off or runs at like 25% when you want it too, essentially sealing the room off a bit sometimes. Slowing the air during the dark period really helps the dehumidifier zap out the moisture from the plants & cab better, especially the RH spike after lights off.

Keep in mind they add some heat. Does yours have a continuous drain option?

Without a lung room you don't have much choice, unfortunately mother nature has alot of control..

 

[Douglas.Curtis]

Active intake, blowing through a dehumidifier.

Look, you're really going to have minimal results with that. Dehueys are not designed to do this, they're designed to remove air from a certain space. The more humid it is, the more effective they are, yet it takes time to drop the humidity.

A single pass through a dehuey is going to be pretty much pointless. Better to make sure the room stays hot and keep your transpiration high, your plants won't be using transpiration to stay humid, that's for sure.

 

[CptnFeatherswrd]

That controller won't work on my voltage. I can set the fan up on a timer so it turns off at night giving the dehumidifier a better chance to do its thing.
I will set it up with a drain hose/reservoir so it never fills up

 

[CptnFeatherswrd]

Active intake, blowing through a dehumidifier.

Look, you're really going to have minimal results with that. Dehueys are not designed to do this, they're designed to remove air from a certain space. The more humid it is, the more effective they are, yet it takes time to drop the humidity.

A single pass through a dehuey is going to be pretty much pointless. Better to make sure the room stays hot and keep your transpiration high, your plants won't be using transpiration to stay humid, that's for sure.

So you think turning the fan off at night to give the dehumidifier a better shot will decrease the transpiration rate compared to leaving the fan on?

 

[Douglas.Curtis]

So you think turning the fan off at night to give the dehumidifier a better shot will decrease the transpiration rate compared to leaving the fan on?

Cannabis thrives on transpiration. You want to avoid large changes in transpiration though. The higher the transpiration rate, the less nutrient/amendment you need. When transpiration spikes and nutrition stays the same, overfeeding quickly occurs.

Plants use transpiration for two main actions to combat unwanted conditions. They use it for cooling, when the temperature goes above about 70F (most plants want 70'ishF temps), accomplishing it through evaporation. They also use it for hydration, trapping evaporated moisture within the trichome layer.

You need to maximize transpiration for one of those actions, either hydration or cooling, since cannabis is unable to do both healthily.

So, hot room, high humidity or cool room, low humidity. Look at what you can do the most efficiently and go for it. Keep in mind that trichome bearing plants grow more trichomes in low humidity, to trap more moisture.

Does that help?

 

[Mikell]

You really need to stop guessing at information.

https://en.m.wikipedia.org/wiki/Transpiration

Learn the basics first. Trichomes exude oils to retain moisture

Hooking up a dehum inline is inefficient, but it works. Don't expect miracles, but like raising a dehum, you can squeeze a little closer to your idea of ideal.

 

[Douglas.Curtis]

You really need to stop guessing at information.

https://en.m.wikipedia.org/wiki/Transpiration

Go look up trichome bearing plants and their response to humidity. You'll find a universal truth among them. The higher the humidity, the lower the trichome count.

I have looked it up, I'm not guessing in any way.

 

[Drop That Sound]

Up here in the NW, sealed or not, without a dehumidifier or lung room you are pretty much screwed most the time..

My 6.5 x 7 x 6 flower room, has 3 passive intakes. 2 have the 5 inch flexible ducting I was telling you about. I aim the one thats closest to the main outside air source right at the back of my 50 pint which sits by the door(which is also vented), and it blows down the center of the room between 2 scrog systems. Drops the RH from %65-99 percent or whatever down to 40-50%. It cycles almost continuously when the lights are off, unless you slow the air down with a controller. Hardly runs when the lights are on.