Dehu which one? specifically.

Hey gang been going through the old threads and found great info on dehumidifiers. Most of them are a year or 2 old so none of the links work to Amazon. I'm still not sure which actual model/size will work with my situation. 2x4 tent in 8x5 room. Today rh is 68%. But most of the time its upper 70s. I'd like to get the humidity down to optimal levels 55-60. I will be adding an window ac 5000btu at the same time. Which should help I just dont have those numbers yet. The plan also is to dry the flower on a hanging rack in the 8x5 room.
On paper you would think a little dehu would do it, but from what I read to actually drop and hold the rh it takes a bit more work.
Thanks!
specs: 4x2, ES led, 6in inline with filter (passive for now), 2 mini fans in tent, local soil mix, 4 autos 3 weeks old.

I’ve been using a Frigidaire 70 pint for about 3 years in a 6x8 (actual canopy is 4x7, 14 plants in 3G pots fed 10G daily). Has no problems keeping RH down, think it cost around $240. A 50 pint would probably be fine for your needs as well. I would recommend getting one with a continuous drainage option if you don’t feel like emptying the small reservoirs all the time.

Bakersman said:

Hey gang been going through the old threads and found great info on dehumidifiers. Most of them are a year or 2 old so none of the links work to Amazon. I'm still not sure which actual model/size will work with my situation. 2x4 tent in 8x5 room. Today rh is 68%. But most of the time its upper 70s. I'd like to get the humidity down to optimal levels 55-60. I will be adding an window ac 5000btu at the same time. Which should help I just dont have those numbers yet. The plan also is to dry the flower on a hanging rack in the 8x5 room.
On paper you would think a little dehu would do it, but from what I read to actually drop and hold the rh it takes a bit more work.
Thanks!
specs: 4x2, ES led, 6in inline with filter (passive for now), 2 mini fans in tent, local soil mix, 4 autos 3 weeks old.

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It really depends... I use a 34 pint dehu in a 10x10 room and I can drop from 70 rh to 45 rh in under an hour. The trick is getting it stable..mine has been running for close to a year straight in my old house (about 2 gallons per day EVERY day) and my humidity rebounds to 50+ pretty quick when I turn it off. The problem in my case is an old ass house with bad insulation. Depending on your house/space and the insulation (not to mention local weather conditions) the needs will change.

EDIT:
How often are you willing to go out and empty it? Do you have a drain available?

I have a 30 pint HOmelabs dehumidifier that reduces my RH in 390 sq ft by 10% in under an hour. Any of the ones mentioned will work for you. As the other fella mentioned, some of these you can pull the hose out of the little container and point it down a drain. Works great for me because my bathroom is right off my grow room.

Thanks guys this is what I needed some actual proof what machine can drop rh in my environment. Like today its 84 deg f, 71% rh feels like 90deg and 90% rh!

Also anyone run an ac in your small rooms? just wondering if you know how much the humidity drops once you get to your desired temp with out the dehu on. I assuming temp drops as ac rooms always feel dryer.

SpawnOfVader : Yes I have an old house also, built in the early 70s. Single panel walls with jealously for windows. I did caulk the hell out of the 8x5 closet and plan to board off the window once the ac is mounted. yes I can add a drain. I work in the restaurant business and we have to empty the condensation drip trays daily. in fact we run a hose to a 1 gal jug so we can make it to the end of the day without it over flowing!

I run A/C, along with Dehu, humidifier, an 6” intake & exhaust. I leave the Dehu & humidifier on all the time set at 55-70% RH depending on stage of flower. A/C I have on a timer to run during the day during lights off. I run the 6” inlines on thermostats at night during lights on.

A/C works by drying the air so it does lower the humidity while it’s running.

My Dehu has a hose attachment on the back so you can screw on a hose for continuous drainage.

This one is on my xmas list.
4x8x8. Currently using a 50pint non-wifi.

This one will allow me to schedule different day/night settings. As well as allow for remote management via app.

Bought this one. Works really well, fact so well it dried out the drywall to the point the nails started to come out the walls. I used it in the room acting as the lung for my tent. Its large enough to draw all the moisture out of our house easily. I bought it on the assumption bigger is better, might not be so with dehumidifiers but now I have it incase I expand my grow space.

https://www.amazon.com/gp/product/B07JMZJX4B/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

NukaKola said:

I run A/C, along with Dehu, humidifier, an 6” intake & exhaust. I leave the Dehu & humidifier on all the time set at 55-70% RH depending on stage of flower. A/C I have on a timer to run during the day during lights off. I run the 6” inlines on thermostats at night during lights on.

A/C works by drying the air so it does lower the humidity while it’s running.

My Dehu has a hose attachment on the back so you can screw on a hose for continuous drainage.

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Yes this is exactly what I want to do. Electrician comes wed to add another breaker Do you run the intake at the same rate as the exhaust? I was just looking at intakes, thinking of doing a 4in since my set up is so small. plus I'm thinking the room will be much cooler so I wont have to have the fans on super sucking calapse tent high. That's what I call setting 10.

TintEastwood said:

This one is on my xmas list.
4x8x8. Currently using a 50pint non-wifi.

This one will allow me to schedule different day/night settings. As well as allow for remote management via app.

Amazon.com - Vacplus 50 Pints Dehumidifier with WiFi Remote for Large Rooms, Large Capacity for Basements Bedroom & Home, Dehumidifier Removes Moisture Efficiently, Two Continuous Drainage Mode with Dehumidifier… -

Amazon.com - Vacplus 50 Pints Dehumidifier with WiFi Remote for Large Rooms, Large Capacity for Basements Bedroom & Home, Dehumidifier Removes Moisture Efficiently, Two Continuous Drainage Mode with Dehumidifier… -

www.amazon.com

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I like this one. its mega over kill for me but who knows might end up jumping to the spare room in a few seasons!

farmingfisherman said:

Bought this one. Works really well, fact so well it dried out the drywall to the point the nails started to come out the walls. I used it in the room acting as the lung for my tent. Its large enough to draw all the moisture out of our house easily. I bought it on the assumption bigger is better, might not be so with dehumidifiers but now I have it incase I expand my grow space.

https://www.amazon.com/gp/product/B07JMZJX4B/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

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Wow yes that's the type of Dehu that I would need. Looks like Amazon got the licenses for that one now. I have no complaints with Amazon essentials. They are like Kirkland Signature (normally a name brand rebranded) cant go wrong.

You guys who are growing at home, are you running in sealed rooms or is your grow room just an extra bedroom/whatever?

I have the Frigidaire 50 pint (formerly 70 pint, they changed the rating system). It is fantastic. But I live in a small old house and I'm pretty sure I'm dehumidifying the entire house. There's no way to really get around that unless you're sealing the grow room and running a separate AC for that room. I've experimented with the dehu located in the grow room, in the 4x4 tent ( no way , too hot already ), and putting it further from the grow room - that works too. But even with the dehu sitting right outside the tent, I can get the room down to 37% RH, and inside the tent it's still sitting at a minimum of 50%. I have to watch it and the fan speeds to make sure I don't go above 60%. Guess I'm still getting it dialed in perfectly.

Anyways, yea the Frigidaire is a solid unit and is also highly recommended by http://www.dehumidifierbuyersguide.com/ - not a bad resource if you haven't read through it.

Bakersman said:

Yes this is exactly what I want to do. Electrician comes wed to add another breaker Do you run the intake at the same rate as the exhaust? I was just looking at intakes, thinking of doing a 4in since my set up is so small. plus I'm thinking the room will be much cooler so I wont have to have the fans on super sucking calapse tent high. That's what I call setting 10.

Click to expand...

The intake and exhaust run at the same rate because they are connected to the same thermostat. The thermostat is key so they aren’t running all the time wasting the dehumidified air. The lights and dehu warm the room to 83-85F and when temp goes over 85F the fans come on to cool the room back down to 83F.

If you run a 4” intake & 6” exhaust the tent will still likely be sucked in from the negative pressure. Negative pressure helps with odor if you are concerned about smell. Even running an exhaust and passive intake would probably work fine for your setup.

NukaKola said:

The intake and exhaust run at the same rate because they are connected to the same thermostat. The thermostat is key so they aren’t running all the time wasting the dehumidified air. The lights and dehu warm the room to 83-85F and when temp goes over 85F the fans come on to cool the room back down to 83F.

If you run a 4” intake & 6” exhaust the tent will still likely be sucked in from the negative pressure. Negative pressure helps with odor if you are concerned about smell. Even running an exhaust and passive intake would probably work fine for your setup.

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ok great huge help. Yes smell is a concern. I did open up some more vents in the tent to help with the cooling and neg pressure. only thing is the vents are not screened. I notice a few nats and things on my midnight peek.

I run a way oversized a/c unit (23k btu) in my tiny cabin (288 sq ft) and I still had 70%-80% humidity inside even with the air cranked. Honestly I thought my humidity gage was broke because I didn't think there was any way it was that high. Got a mechanical guage and it was reading the same thing. Luckily fall decided to show up and got rid of the swamp ass humidity we have around here just im time to dry. Next summer I will definitely be running a dehumidifier, the ac didn't dehumidify nearly as much as I thought it would. The heater though, dropped it around 55% within 30 minutes.

GrassBurner said:

I run a way oversized a/c unit (23k btu) in my tiny cabin (288 sq ft) and I still had 70%-80% humidity inside even with the air cranked. Honestly I thought my humidity gage was broke because I didn't think there was any way it was that high. Got a mechanical guage and it was reading the same thing. Luckily fall decided to show up and got rid of the swamp ass humidity we have around here just im time to dry. Next summer I will definitely be running a dehumidifier, the ac didn't dehumidify nearly as much as I thought it would. The heater though, dropped it around 55% within 30 minutes.

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Having an oversized A/C won’t lower humidity as much because the compressor will keep cycling on/off frequently. So even if the A/C fan continues to run it won’t actually be lowering humidity if the compressor has cycled off.

Well that makes sense

If you want to control it with something else, the dehumidifier must be analogue controls, no digital interface! Something to think about when you operate it with a solenoid (Power on/off) in an automated envirnment. This is analogue https://growershouse.com/dehumidifier-analog-controls-20l-per-day for an example, no digital read outs.

Jesusgrowsmygrass said:

If you want to control it with something else, the dehumidifier must be analogue controls, no digital interface! Something to think about when you operate it with a solenoid (Power on/off) in an automated envirnment. This is analogue https://growershouse.com/dehumidifier-analog-controls-20l-per-day for an example, no digital read outs.

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Some of the ones with digital controls support the "Auto Restart After Power Outage" feature so if it has that it can still be used. Same with portable AC's that you wanna run on a controller.