Help regarding ventilation

Hi. I'm trying to set up my first grow tent. It's a Secret Jardin Hydroshoot 5x5. The problem is the ventilation. I have tried just about everything but it either gets way too warm (32c/90f) and low humidity (40%ish) or the other way, too cold (15c/50f). I have the grow tent in a fairly big insolated garage. When it was too hot in the tent I tried to open a window and send the exchaust air outside, but the the temperature dropped outside and now it's too cold on the tent during dark hours.
Been struggling and wasted so many hours with this now.
Should mention I have HPS light. I Know, upgrading to LED would probably solve the problems, but it's too expensive right now. Any other tricks I can try?
I have a massive 250mm exhaust fan running on lowest option to take air out, and one inline fan on 125mm. I have a couple of fans inside the tent to help with air circulation and one humidifier.

Hi! Adjusting to the changes in environment is always a challenge and requires a custom solution for each situation.

I would recommend a small oil filled heater that you turn on during lights out. If the tent has room, put it in there, it's a lot easier than heating the whole garage.

Too cold is usually an easy fix like this. Humidity should get lower and lower as Winter approaches.

ComfortCreator said:

Hi! Adjusting to the changes in environment is always a challenge and requires a custom solution for each situation.

I would recommend a small oil filled heater that you turn on during lights out. If the tent has room, put it in there, it's a lot easier than heating the whole garage.

Too cold is usually an easy fix like this. Humidity should get lower and lower as Winter approaches.

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Like he said a oil heater should be ideal for your needs just make sure to cover any red lights on it if the one you get has any on it its enough to mess with a plant if its close enough in its dark cycle

Switch your light cycle to lights on at night.. Off during the day..

Thanks for replies! So that's still with the garage window open? Cus ideally I would like to have the window closed, but then temperature rose up to 32c.. I actually have a new heater ready I could try though. I understand getting temp up is easier than getting it down. And humidity follows temperature in a negative correlation kind of way.

Well. A long term solution could be to buy the LED fixture and to swap them out depending upon seasons.

Turn up your exaust fan experiment till its a bit better maybe

Problem with the exhaust fan is it's too powerful on more power. The under-pressure gets too big. Always something... I too agree that buying a LED light solve most issues. But would like to get it to work with the HPS. I mean, others gets it working, so then so should I...

Ac Infinity makes a nice 4" and 6" exhaust fan and filter if a smaller unit would help
They are both under $200 w the filter.

You need the intake bigger than the exhaust. I just use an exhaust fan and let the intake just come in though a elbow.

Three Berries said:

You need the intake bigger than the exhaust. I just use an exhaust fan and let the intake just come in though a elbow.

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I tried that in the beginning. Used a normal 125mm inline fan as exhaust, and only open vents for intake. But the temp got way too high.

What's it run with the bigger fan on high with no intake fan?

ComfortCreator said:

Hi! Adjusting to the changes in environment is always a challenge and requires a custom solution for each situation.

I would recommend a small oil filled heater that you turn on during lights out. If the tent has room, put it in there, it's a lot easier than heating the whole garage.

Too cold is usually an easy fix like this. Humidity should get lower and lower as Winter approaches.

Click to expand...

You can get propane bottles that have infrared heaters on them. Something like this.

Three Berries said:

What's it run with the bigger fan on high with no intake fan?

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On high? The tent would implode.
I almost ripped the seems when I closed the door after cracking it up to close to middle.

Mrwilliam said:

I tried that in the beginning. Used a normal 125mm inline fan as exhaust, and only open vents for intake. But the temp got way too high.

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This doesnt sound right. What vents are open for intake? Juat the bottom ones?

Three Berries said:

You can get propane bottles that have infrared heaters on them. Something like this.

Click to expand...

That's good for the garage, maybe, but dangerous as fuk and an oil filled one in the tent or garage would be safer.

If your fan is too powerful for passive intake, you need another fan blowing air into the tent at the bottom. My exhaust fan is the same way. You just need to find a balance during both cold weather and hot weather, add an AC, add a heater (for the garage, not the tent), dehumidifier etc. My light and dehumidifier heat my place so much during the winter I have to get up and open up my front door during the middle of the night for a few minutes to cool it off, and that's with snow outside.

ComfortCreator said:

That's good for the garage, maybe, but dangerous as fuk and an oil filled one in the tent or garage would be safer.

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Not meant to use in the tent.

You should cut the air flow way down when the lights are off, say run it off a humidistat? And a small electric heater with a thermostat would work good. Just make sure it's big enough to cycle. I've got a 1200 w one that has a good t-stat way down below freezing I use in the garage by the water lines. Doesn't run much to keep the area that is semi open above freezing. I originally had a small one like I posted earlier but it just ran all the time. That small one would work good with a low air flow or the humidistat running it in the tent.

You can get humidistats cheap from humidifiers that people throw away......

Put this in as an exhaust fan at the bottom for wen the lights are out.

Here's something to consider....

TOPGREENER Humidity Detector PIR Occupancy Sensor Light and Fan Control Switch