DIY cooling box, do they work?

[Guest]

Planning for next project... lot's of fun ahead!
Having a slight heat issue, can't use an AC in grow tent.
Has anyone successfully made a cooler box that sits outside tent,
with an air intake fan on top blowing down,
using reusable ice packs for cooling media that lays in middle of cooler box,
on a wire mesh with space below,
output fan with tube at bottom of cooler box, under the ice packs,
blows cooler air into tent, that works in a 4x4x7 tent?
A good cooler box 32 liter/8.5 gallon can hold low temp for maybe 14 hours,
but if you blow air through it, the lower temp will last a much shorter time.
A good cooling media can have -21C = -5.8F
I've seen DIY videos, but do they really work?
I'm thinking, yes, they probably work, but for how long, how many hours before you need to replace the ice packs?
Thinking it's not a good idea for the plant if temps will go up and down and up and down, an even temperature is preferable, right?

Any input will be much appreciated.

[Ckbrew]

Buy your ice by the ton.

@Ckbrew
Exactly, or get a super large freezer for the coolant.
I'll skip that coolin box, but it would have been fun to build one.

[3Berries]

Generally speaking you need humidity too so why not use a water swamp cooler on the intake? Especially if the ambient RH is low.

[3Berries]

The higher the temp the more water the air can hold; the more water the air can hold the harder it is to raise the temp.. I target 83F and 71% RH. Gives me a VPD of 1.10 or so, just a little dry.

Isn't that a bit too high a temperature? I thought ~ 25 C - 77 F was ideal for veg, a little lower in bloom.
Especially lower for some phenotypes I'm planning for.

[3Berries]

If I were growing outside it would be similar temps but much bigger swings.

I find the 83F/71%RH to be a sweet spot with the heat my lamps make and ease of keeping the RH at a good VPD number ~1.10. I even use a 50w LED as a heater that cycles at 81F-82F.

In winter with the room temp under 70F it runs cooler, but then I use a heater to bump the temp at first light for veg. In flower I use bucket heaters to maintain the soil temp around 73F or so.

But I'm not worried about max Terps.

[Satyaban]

Depending on where your tent is, what are the chances of venting a small AC into your tent, For instance if your tent it in a basement, and you weren't too concerned with temp in the room, you wouldn't need to mount an A/C in a window and channel cold air to tent.
Where is your tent?

[Guest]

Trying to figure out how to take control of climate in grow tent.
Here is a schematic sketch.
Is this gonna work? Any input highly appreciated.

[3Berries]

How many watts of heat you lighting up with?

300 W LED from wall.

[Satyaban]

What is the room temperature where your tent is? Heat is not a problem for me in my 4x4x8 with 2 120W LEDs and don't think I have a problem. I am with 3Berries on that.

[Ckbrew]

I don't think so. The output from the AC is going to be in the 40* range and will over cool the tent. You would have to mix room air with it. Also those portable AC units are inefficient. Better to put a window AC in the window, making a lung room around the tent.

Ckbrew, 3Berries, Satyaban
Thanks guys, for the input, appreciate it!

18~22C | 64~72F in coolest room/house winter
23C~ | 73F and hotter summer
Bottom line, it will be too cumbersome to use an AC in my situation and setup.
I will do as before, grow in winter when the outside temperature is lower,
which means I can keep a lower temperature indoors, around where the tent is.
I wish I could grow all year round...

[3Berries]

I run 300 w and the ambient right now is 77F, RH 70% in the house. I have the temp limit set at 83F and I have to add quite a bit of humidity to get it high enough. But that exhaust outside. The Veg tent is in the bedroom at 200w max.. It runs the same parameters but exhaust to the room. Sometimes it gets a little tricky juggling things to work out. I have two small misters and they have fixed but varied selectable outputs.