Heat / Cooling issues Please help

[jamesvr6]

Hello!

I have a grow journal currently going. My set up is basically a downstairs cupboard. I have lazily lent up large white wooden sheets to act as 4 sides to give a nice box of approx 1.5x1.5 metres.

I am using 9 cfl's and I have recently purchased a 400w hps light - this is whats casuing me the problem. I normally leave the cupboard door wide open during the day to try and get as much air circulating as possible. I have a 7" fan on the floor circulating the air.

My temperature device was a digital one I bought that does inside and also has a probe on a wire to put outside. I left this dangling next to the temperature device. The temps I get are on a hot day 96 degrees inside and 84 degrees for outside??? The probe is literally dangling 3 or so inches from the main unit.

I think the main unit is getting heat direct from the light and the probe is getting more of a circulated temp?? Thoughts?

Anyhow, so I thought I would solve the problem. The cupboard backs onto my garage. So I hired a core cutter and cut a 5" hole into the garage and then fitted a bathroom extractor fan. It is rated at 23 watts and can shift 100 cubic m an hour. I am so disappointed as this cost a lot of money to do and so far I have see zero drop in temps.

I was hoping it would allow me to close the cupboard door but the temps are still far too hight to do that.

So the cupboard;

And if you look at the back left corner you can see the temperature measuring device I have.

Here is the new light;

Here you can see the temp better - notice it has inside above outside below and just next to it is the probe dangling on the bottom right.

Here is the pipe sucking the air into the garage;

I have the pipe angled just above light thinking it would suck rising hot air?

Any help or advice would be much appreciated, thank you for reading!!

 

[jamesvr6]

anyone?

 

[SnowBender]

Where does the fresh air come in from? and what temperature is that?

 

[jamesvr6]

Hey Snow, the fresh air comes in from me leaving the cupboard door open during light hours. I was hoping to only have it open ajar but I have to have it wide open. The fresh air temperature will be the room temperature of my lounge as that is where the cupboard is. I usually have the windows open all day to ensure there is fresh circulation - but the problem is I am in summer at the moment so the air is quite warm.

Thanks for reading

 

[SnowBender]

you need an air intake for the exhaust to do any good, opening the door sometimes aint going to cut it.

 

[jamesvr6]

Thanks. Can you offer any suggestions? I think I may be stuck due to the nature of my set up? The door is open all then time during light hours, I appreciate it is a very big gap, I did not realise what I had done would be sooo ineffective

I'm just a bit gutted now as the work I have done appears to be a bit of a waste of time and money.

 

[SnowBender]

It wasn't a waste, it was just half the job...

cut a hole in wall to another room or outside.

cut hole in door.

cut 1" - 1.5" off the bottom of the door.

 

[jamesvr6]

Thank you, you are being really helpful.

Just so I am not being dumb, can you explain a little slower please.

Cut a hole in the wall to another room. Imagine a perfectly square room. At the left back corner is a cupboard which takes out 1 corner. This cupboard goes all the way into the hallway as it is under the stairs - does that make sense? I have sort of enclosed this using the white boarding. If I was to take the left side board out you would be able to see the cupboard stretch down under the stairs.

So the only wall in the cupboard is either the wall for the lounge enclosing the cupboard or the wall which backs onto the garage - where I have fitted the extraction unit. So only option would be to have a hole into the lounge?

Cut a hole in the door? I have bought a plastic vent that I was going to attatch to the bottom of the door - will this be accptable?

Cut 1" - 1.5" off the door. Why is this if I am also meant to be putting a hole in the door and a wall? Also if I was going to do as above, put the vent in, this was going at the bottom of the door for ease of fitment. How does this affect things?

I hope this makes sense, thank you so much!!

 

[SnowBender]

heh- either one of those should work by them selves. no need to do em all.

The plastic vent might be the ticket, depending on your worries about with light leaks. -since i see no smell scrubber, im guessing being stealth is not a concern?

Is there a crawlspace under the house? You could get nice cool air from there instead.

 

[jamesvr6]

I'm in the UK mate, we don't have things like that under our houses - wish I did that would be ideal.

The vent, I can change and buy a closeable one that I could shut at night time. Smell scrubber? No idea what that is so no don't have any of that. Stealth would be helpful but not a major concern. I have several tuns of Ona Gel to use once the smell gets really bad.

So just to clarify you think if I add the vent to the fron that wil help? It's just that I don't see that in my head....The heat build up is intense in there with the hps light and I am just scared to leave the door shut after I put the vent in as I don't see the vent drawing in enough air to help. Am I just being silly?

Would it be better to have a large fan outside the door blowing air either into the door that coulp be open ajar or blowing into the vent if I was to shut the door?

Thanks again!!

 

[SnowBender]

so long as the intake is larger than exhaust it should make a noticeable difference. put the vent near the bottom of the door.

put the thermometer outside the door with the sensor at the top of the plants so you can see whats going on with the door closed.

do you run lights at coolest time of day?

 

[jamesvr6]

Ok that sounds cool. Although just to be difficult why do you think the vent would be so effective as against the door being left ajar, out of interest?

Good shout re the thermometer.

The lights unfortunatley are run during the hottest part of the day - something to learn for next time!!

 

[SnowBender]

thx 4 reps/points!

with the door ajar the air takes the shortest path, in at the top of the door and out the exhaust. while the air under the light and around the plants basically just sits there.
having the fresh air coming in at the bottom and exhausting at the top is way more effective way of cooling. your idea of placing exhaust above light is spot on. -But a stiff and over sized duct (you can easily make one from foil backed foam and foil tape) would be slightly more efficient than the small sized flexi duct. since bathroom fans generally over-exaggerate their power, even a small increase in efficiency is beneficial.


You should also have at least on oscillating fan in there to stir up the air and strengthen the plants. imo every leaf should gently move from air at some point during the "day".

Edit: once you get those temps under control and some air movement, you can move the light closer for much better buds. does it have glass and/or a vent option? its got an internal ballast right? (-Internal would have just a simple plug coming out, with no external power supply box...)