Looking for help sizing dehumidifier for 8x8' room

[Weaselcracker]

I'm looking into getting a dehumidifier for my flowering room and looking for help picking one. The room is a little under 8' x 8' in size. And I'm trying to go as small as I can get away with. I draw air from the outside world which, where I live, has naturally high humidity. During lights off my RH can easily get into the 80s, probably higher if I was to be honest and admit it, especially if i have been in there watering or flushing plants. I sometimes have mold issues. I've been using this room for years and learned to control the issue, with fans and by topping and avoiding growing huge buds. I seldom get mold but it's often borderline I feel, and I'm getting tired of borderline. And obviously flushing, which makes the RH very high in there, tends to come at the most dangerous possible time when the buds are fattest and I least want to see them rot. I shudder at the thought.
So-I have no experience at all with dehumidifiers and am looking for basically the smallest unit I can get away with using, if this makes sense. Or whatever you good people recommend. I don't want the high power drain if possible, and I feel like if I could even just drop the RH by 10-20% that would be plenty. So maybe I don't need the size dehum that would normally be recommended for this size of space(?) Or maybe this is flawed thinking and a smaller unit just means it would be running all the time whereas a big one would be more efficient. They seem to be rated in pints. I was hoping from the little I've read- to be able to use one that is 40 pints or less- maybe/hopefully a lot less, if it makes any sense. Thanks in advance folks

 

[Jedthedog]

What type of temps are you running ? Maybe a small A/C would work better ?

 

[Weaselcracker]

I live in a climate where the outside temps don't get hot so I use the outside air for cooling. Temps in my room I keep around 75 - 80 and they drop to 65 or so at 'night'. I use the heat from my two 600w hps to heat the room. Cooling is from thermostat controlled intake fan.
It's in the plants night that RH rises.

 

[Fuzzy Duck]

I use dehumidifier in flowering during the lights off myself for the very same reason as you do

20 to 30 pint should be ok my own is rated in liters being 14 liters that is about 28 pints running at 220w with 4 settings and a washable filter.


Your going to need to do some research online tho to help make your choice, some search ideas...

1. dehumidifier reviews.

2. dehumidifiers might bring up some online stores etc.

Look at wattage used, size of water collection tank, settings & if it uses filters or not.

A washable filter is a good idea as some treat air born bacteria.


Cons - most produce heat as a side by product so expect a slight temp rise, most work at a optimal temperature to remove humidity, they only treat X volume of air per hour which may be a smaller volume when compared to an extraction fan for example.

 

[Weaselcracker]

Thanks Fuzzy Duck. You always get my MOTM vote because of your great answers. It was the dehum size that I was most stuck on as a starting point before looking at the other features. A little temp rise at night would actually be a bonus because in winter it dips a bit low. Mind telling me what dehum model you use?

 

[Weaselcracker]

Ok Fuzzy Duck I found it. One of your posts on a different thread mentions your model- the Delonghi 14 litre. I'll check it out and others and read up. Thanks again for the help!

 

[Ripples]

Weasel you mentioned using fans but do you have in-line fans with exhaust outside? I can control my RH with fan speed very easily. Really works well.... Just a thought hope it helps...

 

[Weaselcracker]

Yeah I draw cool air from outside through a passive vent and the outtake fan kicks on when temps get high. This only happens during lights on. The outside air is cool/cold so I wouldn't want to be bringing it in at 'night'. I don't have anywhere to draw warm air from. If I had a heater running at lights off then everything would continue to run and my RH would stay low. But that's a lot more power consumption than a dehum would be. Does this make sense or I misunderstanding what you're saying?

 

[Weaselcracker]

More ramblings. Still looking...
Does anyone know of a low wattage dehumidifier? You would think it would be easy to search dehumidifiers by wattage/amperage rating but no.
I emailed Delonghi trying to find an equivalent to Fuzzy's version in Canada. Haven't heard back yet.
I can't use a high wattage dehumidifier it seems.
I don't want to draw much more power through the circuits my grow is using. During the plants 'night' when I'm not running the lights- I could be running a larger dehumidifier no problem, but not during lights on. I could be using quite a lot more power than I am during lights on but like to play it safe. 2-300 watts extra draw would be fine though.
I have access to a 800 watt dehum. I could run one at lights off on a timer when I have more power available, "in theory". But in reality the units shut down and reset when the timer/power goes off so - even when the timer comes back on, I have to actually manually turn it on and set it how I want. I brought one home thinking I could run it on a timer- only to have my opinion of my own intelligence go down a bunch more once I realized the obvious...
Maybe I should just run a heater during lights off... This would keep things warm and get the fans going and the RH down. Seems a bit wasteful and I'd rather not be hearing those fans going in the day, but it would bring down the RH.

 

[Ripples]

I do not have humidity problems but this looks like it may work? Not that big and has low draw 190w. Only 6 pint water tank (12 US cups) but should run all night without a problem? Not computer savvy or I would put the link here but here's the name..."NewAir AD-250-BL" hope it helps!

 

[Fuzzy Duck]

Mmm i'm reasonable sure Delonghi is a UK firm & i'm not sure if they export their dehumidifiers that far over sea's ?

Just checked some american sites Walmart do some stuff but not over impressed but some links may so some dehumidifiers but Home Depot showed a greater rang even had some Delonghi smallest size was 45 pint.


Could not find wattage tho... may need to copy & paste model number into internet search and see what that brings up through further research


Displayed wattage in volts 115 i think i'm not sure about that stuff in ya neck of the woods tho ?

 

[Weaselcracker]

Thanks guys! Yeah Fuzzy - most of the dehumidifiers don't seem to say the wattage on the retailer's websites. But if I take the model number of a likely looking one and do a google search I can usually find it after that. A slow processs but I'll find something here eventually.
Ripples - thanks for the tip. That dehumidifier is low wattage at 190 watts. It gets crappy reviews so isn't recommended, but I'm reading through something like 150 reviews and finding links in them to better options, so it's turning out to be a big help. I'll post anything I find that seems decent.

 

[Weaselcracker]

So far some of the Soleus model dehumidifiers ( I'm getting Really Really tired of typing that word !!!!! ) look promising. Lowest wattage I can find is about 400 but they ( and some other brands) have an auto restart function in case of power outage- which leads me to believe they could be used on a timer. So I'm searching them by how many pints water they produce - which pretty much relates to wattage though with a lot of variation.

 

[JNew]

just a suggestion. read up on this dehumidifier. small, compact, quiet, no compressor and only weighs 15 lbs. so you could even hang it for added space in your room. has constant draining capabilities and is great for the space your looking to dehumidify. let me know if i can answer any questions for you.

EDV-4000 Rotary Desiccant Dehumidifier

 

[Weaselcracker]

just a suggestion. read up on this dehumidifier. small, compact, quiet, no compressor and only weighs 15 lbs. so you could even hang it for added space in your room. has constant draining capabilities and is great for the space your looking to dehumidify. let me know if i can answer any questions for you.

EDV-4000 Rotary Desiccant Dehumidifier

Thanks Jnew. I have noticed the eva-dry ones. I'm pretty sure I've looked at almost every dehumdifier there is now, lol. In some ways it's ideal, but the more I think about it- the more I'm getting attached to the idea of having a little extra heat in there at night as a debundifier byproduct. My temps do dip low especially in winter and it's something I've been neglecting way too long. I could kill two birds with one stone in this case. I'll probably spring for one of the 30 pint Soleus versions as soon as I can get a few dollars together. I like the idea of the auto-restart which means I can put it on a timer. Thanks for the input though I appreciate it.

 

[Weaselcracker]

A final update to this thread

First of all, thanks for all your help!
I finally found a 30 pint dehum over a month ago, and ordered it. After being lost by the mail system -I tracked it down and now I finally have it installed. I have it plugged into a timer, to turn on during the plants 'night' period. My impressions after a few days-
My humidity has dropped at night down to around 50%, which is what I set the dehum for.
Temps at 'night' are quite a lot higher- in the lower 70s when before they were in the low 60s (lower in winter).
Hoping this spells the end for my bud rot.

Some things I figured out while researching.

Dehums are sized by pints (or liters) of water removed per day.

The number of pints relates, generally speaking, to the wattage of the device. By (very) roughly a factor of ten. The 70 pint model I first tried was almost 900w. The 30 pint model I have now is 300 watts.

The 'auto restart' function (retains settings and restarts after power outage) turned out to be essential for me to run the unit on a timer. Without it, the dehum wouldn't restart via a timer.

The EvaDry dehums sound like an option worth looking at. They use a passive water collection system involving some sort of chemical dessicant, and use little power. They also don't produce heat as a byproduct. In my case I decided the extra heat at 'night' would be a bonus.

 

[TheRoach]

That's awesome!!!
Would you be so kind to share a link or tell me the name of it?
Reps+

 

[Weaselcracker]

Here's the one. Comfort Aire Portable Dehumidifier 30 Pint 115V | The Home Depot Canada

I can't say yet whether it's a good one yet as I've only had it a few day, other than that it meets my requirements, and shipped to me for not too outrageous a price. You may find better options.
I found a couple other options online- but I live in the middle of nowhere and some companies seem to not want to ship here. To give you an example, I found a dehum on Amazon that cost about $250, and they tried to charge me $380 for shipping. No thanks guys.