AC/ Dehumidifier unit in a 80x60cm tent possible?

[Boio_]

Hello Everyone,
the title is essentially the question. I started growing in summer in a small 40x40cm tent and had a lot of fun, however I was fighting the heat with ice packs, which worked out fine in the end as the plants were located in my bedroom with a heightened CO2 supply. To finish the plants I switched them to a bigger tent, which I installed while they were growing. Now I couldn't find units that looked like they'd be any use for a tent as small as that, but I was wondering if there is anyone who can recommend small and effective units and whether they would make any sense at all in a 80x60 tent. I work from home and refilling/emptying tanks regularly is no issue at all. Any ideas to fight the heat in summer (I live under a roof and the top temperature in the tent reached 30° one time, which as far as I understood, given the CO2 situation is still doable for them, but of course not optimal). In the end after help from this forum, repotting and changing the nutrient solution I netted 80grams from three plants, which for my first grow is more than satisfying. Lets see what we can do to make it even more so!

Thanks to everyone who takes the time to reply.

Best regards
Boio

 

[Creeperpark]

How tall is your tent and what kind of lighting are you using?

 

[BudToaster]

i have been looking into peltier cooling and dehumidifying. i use a 6" x 8" x 8" peltier dehumidifier in a cardboard box to dry 4oz in about 48 hours. not the best for taste, but quick and effective.

i got a peltier 250w air conditioner from banggood but haven't tried it yet. plan is to use it in a new flower box - 2' x 2' x 6' - for total air temperature control. the peltier converts hot to cold, but you need to allow the cooling fans to dump the heat somewhere - duct away from the box. my plan is to use the cooling side for summer (ambient 80F+) and the heating side for winter (ambient 40F to 50F). the box is foam board insulated with contained air flow as necessary to maintain acceptable temp.

 

[f-e]

30c isn't bad. Some people aim for it. If you want cooler, you have to think about where the heat is coming from, before knowing how much to get rid of. Even without the grow, is your bedroom getting to 30 anyway?
Do you have air coming from outside, that can be taken straight to the tent. Presuming that outside is cooler.


As much bud as 100w of LED can grow, needs about 100w of de-humidification to get rid of the moisture created. Now you have used twice the power, making more heat. Looking at this as a sealed room, heat needs to leave somehow. As most bedroom tents are taking air in from the bedroom, and exhausting to the bedroom, it's the bedroom needs the air conditioning. Which is better achieved by exchanging the air within it. Either blowing out the window, so air comes in from the house, or, sucking in the window, so air is expelled into the house. A bedrooms worth of air is soon shifted. Quicker than a tent can effect it. So there is no heat or moisture accumulation. Without needing heavy machinery. You really don't want a dehu~ as it will just get hotter. Aircon requires a way to get the heat out the room, just as a simple fan would. However, a simple fan can only get you as cool as the air it brings in (from window or door). Aircon can cool the room below this. On the equator, this could be useful. In Scotland or Quebec it's daft.

 

[troutman]

Put it outside the tent. Your tent is small and you'll need all the room for plants.

 

[Boio_]

Creeperpark The tent is 1.80m and I use a Sanlight Q3W with 120W. I can adjust height and intensity on the lamp. Also the filter and the exhaust fan is inside the tent under the ceiling.

BudToaster Thank you for the tip, I always like to have a product recommended to me by someone who isn't an amazon review. So let me get this straight...what are the dimensions of that air con? The dehumidifier seems small enough to cram into a corner.

f-e Yes, on the really hot days my bedroom goes to 30 and maybe even higher, I'm not sure if I remember correctly. I figured 30 would be ok but google told me it's a bit on the high side as in not optimal...when they say not optimal in this case, how much do you think it affects the final yield or quality?
That's a very good point about the dehu and I woldn't mind a bit of aircon for the room. I only have one window so I can't create a draft without opening the door (and we don't want that hehe) but that is definitely something to consider. Just place the aircon next to the tent and do the plants and myself a favor at the same time. Is there a unit you could recommend for a small room?

troutman
Now I'll count you to the vote f-e cast and it seems you have convinced the people (me) already

Thank you all for the answers so far! Let's get this running smoothly!

 

[BudToaster]

Boio_ here is a page link XD-6028 12V 10A Semiconductor Cooling Equipment Small Refrigerator High Power Ra Sale - Banggood USA-arrival notice-arrival notice

oops! only 120 watts of cooling/heating. i have some 12v 10A power supplies on hand from another project.

 

[GMT]

Run your light at night, it evens out the high low temps a bit. Summer or winter, it helps a lot.

 

[f-e]

Heat needs to leave the room. Putting more equipment within it can't help, unless that equipment is sending heat out. There is no way of making cold. All we can do is move heat away. Away out the room, leaving the room cooler.
If you buy an air conditioner, it will want to blow hot air out the room, or send hot fluid out the room.
The 120w thermoelectric unit above, is 120w more heat in the room, from a device meant to cool it. The device makes one side cold by send the heat to the other side. We must harvest that heat to send it away, out the room.

I see your light is 120w, so your heat source is the weather. Running at night is probably all you need for heat reasons. You still need fresh air though for the plants to get a good supply of co2 which the light converts into plant. Food is down the list, we need air and light. We must also get rid of the moisture.

Think hard about getting air through the room. I have been down hollow walls before. Changed light fittings to styles that hide a hole above. Smoke alarms as vent covers. Furniture over holes. Pictures. Tie dyed sheets pinned in corners. Through floor and roof voids. I love a good chimney, even just to link floors if it's capped. Fake gas fires. Often you can see a rooms been used, as air coming through the floor paints blacks stripes where the boards meet. A good fan can overcome a lot of problems. Can you peel a carpet back and drop a hole into a void, as pushing air into your bedroom, will mean air leaving through the window. Pick the right void, and a light fitting further along can be modified. Giving a 100mm duct. Getting air to a bathroom can be great, as they have extractors of their own, and often light fittings that can be lowered with spacers. The bathroom fan offers extraction and noise cover.

Using a portable aircon is like 1000w and a hose out the window, or a proper vent like a tumble drier installing. If it's normal to have aircon there, then a mini split could be golden.

30c just isn't that hot though. If it's not perfect for your plants, it will be within 10% of optimal. The real problem is growing at 90% capacity. It's actually very high. Demanding of food/vpd/lighting/co2

 

[Boio_]

f-e Alright...that is a lot to take in and sounds like a lot of fun (I love making my operations stealthy), however in my current location all that will not be possible. I think I went as far as I can go stealth wise barring one or two things I am thinking about and planning. When you say a mini split, what do you mean? It's good to hear that 30 degree isn't really an issue. What is vpd? I got the air moving in and out down with the system, so co2 is not an issue. Lighting distance I'm still figuring out, as you know from my last grow I think at some point the light was too far away as my plants stretched higher than expected. I keep seeing people having short bushy plants and I'm excited to try LST this grow.

 

[f-e]

VPD is the new RH. In short, it's about how much more moisture the air can take on, which matters to the plants which is trying to loose it. Though not too fast or too slow. It's the buzz term of the last few years. If someone want's to pick up on this with some charts, please do

Mini split aircon.Two boxes, joined by an umbilical cord that's often on a quick disconnect. One box sucks up the heat, the other chucks it out. Just like a whole house fixed installation, but portable.