mallett

High All,

I am currently growing 10 plants in my attic but temps are a major issue now that I have got both of my Hps Lights Running.
With my 155w floro running by itself I could maintain a steady temp of 23Degrees Celcius. Then I switched on one Hps and it went as high as 30 Degrees Celcius. Now I have 2 Running I have seen temps as high as 33 Degrees Celcius. My humidity has also dropped to 15% (from a steady 60%) with both HPS Lights running.
My Hps lights are full spectrum grolux 600w.
My plants are one month into vegging in 5 litre pots with multipurpose compost and I have recently flushed them due to overferting. I have had a large number of leaves go yellow and all of the new ones forming are yellow. My guess is that they are suffering from heatburn aswell as over-ferting?
I have a 10,000 BTU A|C Unit up in my attic but it just isn't cutting it, I have the exhaust on the A|C Unit coming down through my loft hatch and out through my bathroom window. I have also set up 2 oscillating fans on max blowing inbetween both HPS lights to prevent heatburn. Both lights are roughly 2.5 feet away from the plants and the plants are around 20-25 cm high. My daytime temp is around 33 celcius no matter what I do!
I guess I have sufficient ventilation with just this A|C Unit? but this is my first grow ever!
I know for a fact that the HPS Lights are causing my heat issue is there anyway I can cool them or is there such a thing as cool HPS Bulbs available?

I really need help with this heat problem as it could kill my girls

Peace,

mallett

harrad

AC won't work well if you can't keep the backside cool. Is the AC exhaust DUCTED out your bathroom window or are you just trying to blow it out with fans?

10,000 BTU should remove the heat from 2,000 watts of lights, but what is solar energy contributing?

Are you running at night?

__________________
Do you have enemies? Good. That means you've stood up for something in your life. -- John F. Kennedy

Fillabong

Are cooltubes in your growers glossary?

Cooltubes are transparant tubes that encase your lights and contain and direct heat. Most have 2-4" openings to which you can affix little inline fans and laundry ducts. They'll solve your heat problem

lilbud99

Hi mallett

Heres a pic of my cooltube, which is similar to what Fillabong described.... my unit is about 2ft long and 5" in diameter....and houses the same as your using... a 600w grolux i have flexi ducting at one end and as you can see from the pic... a small 12v comp fan on the other end, this is wired up to an old multi voltage adapter.. i can then change the speed of the fan by altering the volts..... this really helps control temps.... virtually removing most of it before it enters the grow area....... because of high outside temps..... your ambient room temp will be high anyway.... so you really need a source of cold air coming into the room..... i have an active intake.. underneath my floorboards pulling the coolest air in the house into the cab, the duct is just out of shot...... this comes on and goes off with the lights so not to lower it too much during lights off......

if the AC is not controlling the temps.... its not working efficiently.... how have you got it ducted out???? it may work better to suck the cold air from the AC into the grow room from outside it..... using an active intake..... just my bud.....

cooltubes or aircooled hoods are the way forward for the summer... just gets too hot, especially in an attic...

Best of luck mate.

Lilbud

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mallett

Thanks for the replies.

Harrad - My A|C Unit is a portable one and the exhaust pipe gets extremely hot! - Do you have any suggestions for cooling as that would help.

I am quite new to growing as you can all tell! does the air conditioner provide the fresh air needed but can't because it's exhaust isn't sucking enough air out of the growspace?

Therefore I need to get a more powerful exhaust so that the A|C Unit can work properly?

Fillabong & Lilbud I would also make some cooltubes for my lights but I'm not totally sure how fellas!- I'd be interested to learn!

Also, If I got a humidifier would this help lower temps?

and......lol Is there such a thing as a Cool HPS Lightbulb like there is floro?

Thanks everyone!

Peace,

mallett

harrad

maybe a bigger exaust pipe, If your using 4" get a couple adapters and duct with 6" or 8". maybe an inline booster fan would work too.

I did however miss the obvious the first time, cool tubes are WONDERFULL! Research that option in greater depth for sure.

Peace, Harrad

__________________
Do you have enemies? Good. That means you've stood up for something in your life. -- John F. Kennedy

mallett

I'm not quite sure what an inline booster fan is. Is it some thing I can put in the exhaust to make it exhaust quicker?

Peace,

mallett

HARDON

Inline boosters suck unless you are running PVC.

They have very very low static pressure levels...put any resistance against them and they suck even more.

Before everyone jumps on the band wagon with the kool tubes....

Remember....

One of the reasons MJ produces resin is to protect the flower...from bugs, predators, dust and dirt and also.........UV RAYS....

The MJ plant is proven to produce more resin containing trichmones when exposed to higher UV RAYS than when not.

Kool tubes are a trade off in potency, as glass such as the kind used for heat protection BLOCKS the UV RAYS from hitting the flowers of the plant.

The plant therefore is not forced to respond by producing more resin.

Those high temps you are having are not a problem until they are seriously into flower mode. The fan leaves will become HUGE to shade the flowers....and hence....reduced light will result in decreased yeild.

Now keep in mind if you are running only HPS, this is not a factor as HPS does not emit UV RAYS...(another reason to add MH to your flower stage)

Those portable AC units....create as more heat than the create cold....

The cooling fins of the unit must be OUTSIDE the grow chamber.

Additionally, if you are running an AC unit, and you continue to blow or suck in outside hot air, you wont accomplish anything.

AC works by taking the same air and re-proccessing it gradually dropping the temps. Let hot air in, and it is not recirculating.

The easiest solution....if you have the mechanical skills, is to buy a small refridgerator unit, take off the door, and place it so the open face is now part of the grow chamber.

Place it at the bottom of the chamber, as heat rises....cold sinks.

Place a passive intake of 4" at the BOTTOM NEXT TO THE FRIDGE UNIT...

This passive intake will be drawn into the refridgerator over and over eventually building a high pressure weather like environment.

You force exhaust will pull the cooler air from the bottom up thru the foilage and canopy and cool the temps.

Make sure you have a serious exhuast fan right nest to the light bulbs as well.

You can always weather it out too.

Just trim the fan leaves when they get too big that they shade the flowers. Keep the ladies well watered and dont allow them to dry entirely....

Nothing bad will happen...the yeild will just decrease a bit.

Also, an A/C unit will dry the air considerably...this is NOT a bad thing in flower stage, but is in veg stage...hence the need for humidifier in veg state.

When flowering, the MJ plant will produce more potent resin with dry air.

No solid answer other than expect heat issues when growing in summer...but it wont kill your plants.

Some of the best weed is grown in southern Arizona...105 F and potent smoke... Afghanistan, Pakistan and the Middle Eastern regions, all dry, produce some of the best weed around!

Good Luck

mallett

Thanks for the useful info HARDON I will bear all of that in mind.

Peace,

mallett