HELP! Temperature control

[Iceman1066]

Hey guys and thank you for taking the time to read this. I've grown in tents for years and had no problems but now I've gone bigger and using a loft. The loft is fully insulated and waterproofed. X20 plants (gorilla skittles) x6 light's, 2x air in, 1 air out 3 fans. 1st grow last winter temperatures was around 30 degrees which I know is still a tad high but got a good return of around 5oz per plant. Sadly the last grow was hitting temps of around 40 ! I've added an air con unit and reduced to 4 light's but temp today was 33 degrees and they only in veg on 400w light's. Anyone please got any tips on how I can reduce it even more. Any help will be greatly appreciated

[Going2fast]

In a loft it's going to be a problem if you are using HID lights and you can't exhaust the heat they produce. Maybe look into LED lights for your next grow. Can you draw cool air in from the floor below?

[Iceman1066]

I've suggested led lights but obviously they cost. Its definitely something I want to move to in the future. I just need to get through this grow 🙈 sadly I can't draw air in from downstairs but I do draw air in from a chimney and I send the air out to a separate chimney as im blessed with 2 in this setup. Just hoping the less lights and an air con will get me through but just incase was wondering if there was any tips ?

[Ace1973]

I can suggest running your setup at night instead of day, if you are not already.

[Iceman1066]

Yeah trying that. Starts at 4pm but thanks for the thought. Feel like I'm out of ideas, hence this post 👍

[Going2fast]

Had a friend put a window ac unit in her fireplace and it exhausted into the chimney. Maybe reduce the airflow and let the ac do most of the work? Just spitballing here.

[Iceman1066]

Appreciate the thought. We did have quite a long tube from the ac to the chimney to get rid the hot air but found the tubing was getting hot so only on Monday we moved the ac to right next to the chimney so they're is minimal tube showing which has definitely helped.

[Ckbrew]

If you set it up like that you need to provide ducted outside air for cooling the condenser coil. If you do not, the condenser will use room air which is then exhausted as hot air out the chimney. Every cubic meter of air exhausted from the structure must be replaced with air from somewhere. Usually through cracks under doors etc. Then you are sucking hot air back into the structure. This effect greatly reduces cooling efficiency. This same effect is why portable room air conditioners with just one duct to exhaust the hot air are so inefficient. Just a thought.

[Iceman1066]

Tbh ive never had to use an ac before so I thought to ballance the air being sucked out by the ac I'd add an extra air in from the other side of the room.. your reply makes a lot of sense as the ac kicks out really cold air but isn't cooling the room down as much as I had hoped 🙈 cost us nearly £500 aswell but without it it gets way too hot. Arrrrrrgh banging my head against a wall for a solution lol

[TOKABIGONE]

Hey Iceman kind of a weak thought here but maybe you could use 1 gal frozen water jugs surrounded by 4 pots so you would need 5 for 20 plants. Kind of a pain as you would need to replace daily but could help keep your roots cool which I believe is the most critical part. Use a soil thermometer to keep around 65 F.

[Iceman1066]

Nice1. Yeah a pain but ill literally try anything just to get through this grow . Cheers 🤗

[Ckbrew]

iceman 1066 Here is a link to check: https://www.youtube.com/watch?v=BufNIXANedc

This was done for a boat but the same concept can be applied to your setup if you have access to an outside air source. There is no window?

[Iceman1066]

I'll have a watch now thanks. Its in a loft with no windows, only 2 separate chimney breasts

[Ckbrew]

This may be a cultural thing. When you say loft I might say attic and we both mean the same thing. Am I correct, like the space above the ceiling of the top floor and below the roof? If you put energy into a system it will get hot unless you find a way to remove it. Is it yours, can you get creative? Put vent hole through wall, tie into the plumbing vent system for exhaust?

[Iceman1066]

Yeah loft and attic are same thing 😁 its a friend's house who i partner with. The room is fully isolated and a thermal lining to prevent it glowing up like a Christmas tree to thermal cameras lol. Below is a rough sketch of the setup. The air in is coming from 1 chimney and air out plus ac hot air is going out of a separate chimney. Ya can't see on the sketch but we have 2 air ins. 1 in the ground and 1 on the roof blowing down. Also 3 fans moving the air around. Hope this helps? Also really appreciate your help 🙏