How can I cool my room down?

The average temperature in my basement ranges from 70-80 degrees fahrenheit all summer long, so I figure there should be no reason that I am having heat issues. I just invested a little bit of money and installed the cooling kit to my reflector for my 315w cmh, which seemed to have helped a couple of degrees in difference, however, I am still not where I need to be temperature wise. I tried arranging my setup in every possible way and I can only get my 4'x4'x6' room (or at least directly under the fixture) to 85-90 degrees.


At the moment, I am only running a small mars led panel, simply because I cannot keep the temperatures low enough with the 315w lamp. Besides running an a/c unit, which is not really an option, I am not sure what there is left to do. I did some testing today and it never went under ~87 fahrenheit directly under the cmh fixture, and ~84 fahrenheit off to the side of the led panel (where the other meter is located).

After those temperatures were standing there for a few minutes, I decided to see what would happen when I left the door to the room opened for passive air intake, which there was not much change under the cmh fixture temperature wise. However, under the led panel it dropped from ~84 to ~82 fahrenheit, which can be seen in one of the pictures.

Air Extraction: 334 CFM Can Max Fan ( https://www.amazon.com/gp/product/B004C2IWIE )
Air Intake: Lowes Inline Fan (https://www.lowes.com/pd/SUNCOURT-Inductor-6-in-Dia-Galvanized-Steel-Axial-Duct-Fan/1000018191 )

Flowering Room



---

How can I cool down my area effectively without an a/c unit? If my basement ranges between 70-80 degrees fahrenheit -- can I reach those same temperatures in my enclosed flowering room?

With enough air flow you can

Add CO2.

Beef those bitches up.

$0.02

Can you vent the heat out? A powerful enough fan will be able to pull out a good amount of the heat especially if you can get it at ceiling height and vent it out of the house.

@JohnCee see where the light line is on the walls, move the thermometers above that line so its not in direct light and then see what its saying. I would cool it down first in the fridge or something, those things take a while to cool. Then reposition it as I said out of direct light and come back a few hours later and tell us what the temps are.

I have a similar room, 4'x5.5'x5.5', and it's lined with bubble wrap insulation and pandawall. Running a 400w solistek MH for veg and my temps are between 73°-82°. 65-75%rh.
I use a yield lab 440cfm fan and pull the air out of the room and passively pull air in from an adjacent room.
I had the same problem as you except I was up to 90°, and it was because I was pulling air from the same room I was exhausting into.
I also learned from this site I didn't have enough intake ventilation; smaller intake than exhaust. I guess your intake should be 1.5x larger than your exhaust. I made those 2 changes and my girls are comfy now.

If you are trying to cool with the basement air, you will need to cool it with air that is approx 10-15*F cooler than the temp you want to achieve in the grow room. Bout the only way to get lower temps without AC. Eventually your just going to heat your basement up to the temp of the tent if you are pulling from the basement, and exhausting into the basement as well. You would need to pull in basement air cooler than the temp you want to achieve, and exhaust the heat out of the same room you are using to cool with.

You could pop a dryer vent in and exhaust outside

Ugg boot said:

With enough air flow you can

Click to expand...

What do you recommend that I do to achieve that -- focus on pushing more air into my room or extracting?

Enigma said:

Add CO2.

Beef those bitches up.

$0.02

Click to expand...

I'm not sure about CO2.. I'll have to take this into consideration more.

mjinc said:

Can you vent the heat out? A powerful enough fan will be able to pull out a good amount of the heat especially if you can get it at ceiling height and vent it out of the house.

Click to expand...

The heat is extracted through the light fixture into the ducting, which leads behind the enclosed room and through the carbon filter and back into the basement air. I thought that releasing the hot air back into the basement would make a difference, however, I set a thermometer behind the room and the average basement temperature still showed 72F (this was a medicated test and the results are a bit fuzzy). In one of the pictures you can see the ducting from the light leading into a hole at pretty much ceiling height (highest point on the wall).

coreywebster said:

@JohnCee see where the light line is on the walls, move the thermometers above that line so its not in direct light and then see what its saying. I would cool it down first in the fridge or something, those things take a while to cool. Then reposition it as I said out of direct light and come back a few hours later and tell us what the temps are.

Click to expand...

I'm not positive why I would want to gauge the temperature outside of the direct like, because that's exactly where the plants are going to be sitting.. right directly under the light. Can you elaborate on the purpose of this a bit?

CBDeez said:

I have a similar room, 4'x5.5'x5.5', and it's lined with bubble wrap insulation and pandawall. Running a 400w solistek MH for veg and my temps are between 73°-82°. 65-75%rh.
I use a yield lab 440cfm fan and pull the air out of the room and passively pull air in from an adjacent room.
I had the same problem as you except I was up to 90°, and it was because I was pulling air from the same room I was exhausting into.
I also learned from this site I didn't have enough intake ventilation; smaller intake than exhaust. I guess your intake should be 1.5x larger than your exhaust. I made those 2 changes and my girls are comfy now.

Click to expand...

I put a thermometer exactly where my air is getting exhausted back into the basement, and there was no temperature increase (this was a medicated test and the results are a bit fuzzy) which made me feel like that wasn't the issue at all. I am giving serious consideration at replacing my ventilation fans, however I really cannot be spending money into something that will not work for me. I can easily run some ducting and vent the hotter air away, but it's actually pin-pointing that as the solution and knowing which fans to run.

HydroRed said:

If you are trying to cool with the basement air, you will need to cool it with air that is approx 10-15*F cooler than the temp you want to achieve in the grow room. Bout the only way to get lower temps without AC. Eventually your just going to heat your basement up to the temp of the tent if you are pulling from the basement, and exhausting into the basement as well. You would need to pull in basement air cooler than the temp you want to achieve, and exhaust the heat out of the same room you are using to cool with.

Click to expand...

The basement air is already the coolest air that I am able to provide to my room, as the upstairs air is pretty much always above 80 degrees. I'm not sure where I would be able to find cooler air than the 70-80 degrees fahrenheit provided from my basement already.

CBDeez said:

You could pop a dryer vent in and exhaust outside

Click to expand...

I will eventually rig this up to exhaust the warm air outside, but unfortunately I still don't think that would be enough to help with my current situation.

---

To be entirely honest with you guys I am completely at a loss. I simply want to cool down my 4'x4'x6' area enough to have 3 ladies (one directly under the cmh) and let them finish without getting heat stress. I would like to think that I already have one decent fan, and I have about $150 to work with to resolve my heat issues. Anyone have recommendations?

JohnCee said:

The heat is extracted through the light fixture into the ducting, which leads behind the enclosed room and through the carbon filter and back into the basement air. I thought that releasing the hot air back into the basement would make a difference, however, I set a thermometer behind the room and the average basement temperature still showed 72F (this was a medicated test and the results are a bit fuzzy). In one of the pictures you can see the ducting from the light leading into a hole at pretty much ceiling height (highest point on the wall).

Click to expand...

That's extracting a lot of heat from the light but there's more heat being generated in the room. You're going to need a second extraction to remove that. A grower who uses cooled hoods still needs to cool the rest of the room it just takes less cooling then an open hood system

@JohnCee

The reason you don't put a thermometer in direct light is because the thermometer picks up the radiant heat from the light. The ideal temps often quoted for a grow room are Air temps. By putting thermometer in direct light your heating the thermometer up with the light and your not measuring air temps at all. Plants can take radiant temps of up to 50degrees C.

I'm not just making shit up you know. Every week people come on here and say "help my temps are too high" but the reality is most people overlook how to properly measure air temps. There is a vast difference between radiant heat and air temp.

Read this
http://cannabis.com/faqs/growing/growroom-how-do-i-measure-temperature-correctly.html

Edit, John, if I put my thermometers at canopy level they will read 90 degrees f, if I put them in the correct place to measure Air temp they read 78-79 degrees F

mjinc said:

That's extracting a lot of heat from the light but there's more heat being generated in the room. You're going to need a second extraction to remove that. A grower who uses cooled hoods still needs to cool the rest of the room it just takes less cooling then an open hood system

Click to expand...

I used to use HPS, I cooled 3x 600w in cooltubes in a line in a 2.4mx1.2m tent like this
FILTER>FAN>CT>CT>CT>CHIMNEY that worked fine with an one 8" fan. Passive intake from an open window.

I would move your thermometer out of direct light like coreywebster suggested. The thermometer's being heated and likely giving you wrong temps. The easiest I can explain it is the difference between sun and shade. Being in the sun always feels hotter than being in the shade when in fact the air temp is the same. Putting your hand on a car hood that's been in direct sun is always hotter than the actual air temp is. Your thermometer is absorbing the heat and reading it's temp and not the air temp it's called solar radiation.

[QUOTE="JohnCee, post: 13619460, member: 906538"


The basement air is already the coolest air that I am able to provide to my room, as the upstairs air is pretty much always above 80 degrees. I'm not sure where I would be able to find cooler air than the 70-80 degrees fahrenheit provided from my basement already.
[/QUOTE]
I didnt mean find cooler air. You should be pulling the cool 70-80* air from the basement into the grow room and exhausting the hot air from the grow room outside(not back into the basement) OR you could air cool the hood with air from outside, and have it vent outside as well requiring less cooling of the grow room with the basement air. I run my rooms from outside air during spring/fall/winter and then sealed during hotter months with AC.

Great topic, and great tips! Trying to grow in my new garden shed and I WAS measuring it wrong! Got it right the next time and I do have legit heating issues. Looking into fans now.

Get a Styrofoam cooler cut two holes for your flex duct fill with ice and that should have enough heat exchange to cool that space. The ice will be cooler then the air going through the duct. You just have to adjust the fan speed a lot of water dumping but it works good luck hope this helps