Heat in my grow room is becoming a big problem

[Username97]

I have a 80x80x160cm grow tent in a closet, literally the same size as the grow tent. This means I only have 1 4" duct vent which is currently being used by the carbon filter and outlet fan is located on the roof of the tent, which leads directly to the loft. I have 2 3" vents but no where does 3" fans. I have raised my light as high as possible since it was burning some off my leafs.

I have a viparspectra 900w. I am growing 4 auto's.

Here are some idea's I have;
- Small portable Air Con run that every 3 hours or so.
- The only problem here is that in the grow room it will be enclosed with door shut, will this work?
- Buy some 3" ducting and fan to create some kind of air exchange. (Put fan in loft so pulls air into tent)
- This seems like best option.
- Changing the light system to 6/2 on/off.
- Will this effect my plants too much?
- I feel like 6 hours is still too much time for my environment too heat up above 28 degrees, sometimes can go to 35 degrees if I'm not careful.

If anyone has any ideas please share!

 

[DRM Ranch]

Re: Heat in my grow room is becoming a big problem...

Air exchange should be a one way deal, in from the lowest vent on your tent, out through the highest vent.

The outlet air will be much more warm than you want in the tent so it should be ducted into a space that is away from the tent, an unused attic is great.

Fans pull better than they push, so hang the carbon filter in the tent, run your ducting, and last put the fan on the very end (outlet) of your ducting.

Your closet door is not likely air tight, and air will flow.

 

[Weezze]

Re: Heat in my grow room is becoming a big problem...

You cannot leave the door of the closet open?
I have a portable AC in my room, and it's blowing towards my closet (7' distance), but the door of my closet is always half open.
It was the only way to cool my tent.

 

[DRM Ranch]

Re: Heat in my grow room is becoming a big problem...

If your room air conditioner keeps your room at an adequate temperature the door to the closet can be open or closed.

You just need to make sure the airflow is not recirculating into the air conditioned space.

If your air exhaust fan is not moving air out of the closet space and away from the room you are air conditioning you will of course have issues cooling the tent.

If the air conditioned room is cool, but your tent is not, I would suspect you aren't pulling enough air through it. If that is the case, a higher cfm fan is in order.

You shouldn't need another AC unit if your air exchange is high enough.

Keep the room door closed at the very least, your closet door can be open or closed, with an exhaust fan pulling air through the tent and out of the closet into an attic space clod air will be moving either under the door or through the open door, either way you need enough air flow to regulate the temperature.

If you decide to go with a second portable AC unit for the closet space, look for one that has both an intake and exhaust tube, these both need to be routed to a window or at the very least the exhaust needs to be routed to the attic space and the intake can be left open.

 

[Chris Scorpio]

Re: Heat in my grow room is becoming a big problem...

What's the temp at in the tent??
Room temp??

And open the tent should help alot.
Also have lights on at night when it's cooler

 

[Username97]

Re: Heat in my grow room is becoming a big problem...

If your room air conditioner keeps your room at an adequate temperature the door to the closet can be open or closed.

You just need to make sure the airflow is not recirculating into the air conditioned space.

If your air exhaust fan is not moving air out of the closet space and away from the room you are air conditioning you will of course have issues cooling the tent.

If the air conditioned room is cool, but your tent is not, I would suspect you aren't pulling enough air through it. If that is the case, a higher cfm fan is in order.

You shouldn't need another AC unit if your air exchange is high enough.

Keep the room door closed at the very least, your closet door can be open or closed, with an exhaust fan pulling air through the tent and out of the closet into an attic space clod air will be moving either under the door or through the open door, either way you need enough air flow to regulate the temperature.

If you decide to go with a second portable AC unit for the closet space, look for one that has both an intake and exhaust tube, these both need to be routed to a window or at the very least the exhaust needs to be routed to the attic space and the intake can be left open.

I've got no current air conditioning, I have a 4" extraction fan taking the hot air out of my tent via a carbon filter and ducting which goes out of my roof vent pocket into the loft. I have no air going into my tent. I have the vents open but this doesn't really help.

 

[Username97]

Re: Heat in my grow room is becoming a big problem...

What's the temp at in the tent??
Room temp??

And open the tent should help alot.
Also have lights on at night when it's cooler

I have lights on at night, temp with door shut can get as high as 35 but usually 30, closer temp is 21.

I can't keep door open because of the smell and I'm being stealthy with it hence in the closet

 

[Chris Scorpio]

Re: Heat in my grow room is becoming a big problem...

More air flow sounds like the option, or an ac unit

 

[GodOfPot]

Re: Heat in my grow room is becoming a big problem...

Might need a larger fan, 6-8" would probably make the single largest difference

Home remedy solutions, try keeping a rotation of 2-3 3/4 full frozen ice in 2L bottles, put them in bowls to catch the condensation, switch them out every 12 hours, put a fan blowing at them if possible

 

[GodOfPot]

Also perhaps you have too much foliage which is preventing good air circulation, defoliating can help let the hotter air rise

 

[DRM Ranch]

Re: Heat in my grow room is becoming a big problem...

Your 418W LED light produces enough heat to elevate the temperature in your tent by roughly 27°C every minute.

Most 4" duct fans for our use have a rating of 150 cfm (4247 l/min), your tent is just a bit over 1000 liters in total volume.

The carbon filter at worst is going to restrict flow by half, leaving you with 75 cfm (2123 l/min).

That equates to 2 air exchanges per minute.

1 air exchange will reduce heat gain by half (13.5°C/min)
2 air exchanges will make the heat gain roughly (6.75°C/min)
4 air exchanges brings it to (3.375°C/min)

After some quick looking around a bit it seems that some 4" carbon filters can quickly become a serious restriction in and of themselves. You may want to consider checking the airflow after the whole duct, filter, and fan assembly, then again without the filter.

What temperature are you keeping the room at?

Aside from excessive temps air exchange is your main issue, then air management (where that air goes).

In very basic terms, the more air flow you have the more reasonable a temperature your room AC will need to be set at. So low air flow through the tent means a very low setting on your room AC like 16°C with 2 air exchanges per minute which is really cold for a room in my opinion but would maintain a proper temp in the tent with that light. Double the airflow and you should be able to set your room AC at 19.5°C or 20°C which is way more reasonable.

 

[HigherTheHigh]

4-6 inch intake fan.

 

[DRM Ranch]

Re: Heat in my grow room is becoming a big problem...

I've got no current air conditioning, I have a 4" extraction fan taking the hot air out of my tent via a carbon filter and ducting which goes out of my roof vent pocket into the loft. I have no air going into my tent. I have the vents open but this doesn't really help.

I'm sorry, I read another reply from another person that said they had an AC unit pointed at their closet and thought it was you. My bad, I'm on my phone so I don't always slide over to see the posters name.

I would get a portable AC unit for the room, and set it at the temp noted in my previous post according to the air exchange rates you believe your exhaust fan can create.

The cold air will flow under the door if the lower vents in your tent are open. A couple cheap 3" cone filters for cars added to the existing 3" vent holes will keep dust and most unwanted crap out of your tent.

 

[Guy Cavallero]

I had exactly the same issue in my 3x3. I built a swamp cooler .....Bam mmmm. ....no more cooling issue. Want it cooler, freeze a 2L bottle every night and throw it in the middle. Check my grow.....it's in there. PM me, I'll give you the low down on exactly how I made it. I was skeptical, I even bought an online evaporative cooler. My cooler works twice as good.

 

[DRM Ranch]

I had exactly the same issue in my 3x3. I built a swamp cooler .....Bam mmmm. ....no more cooling issue. Want it cooler, freeze a 2L bottle every night and throw it in the middle. Check my grow.....it's in there. PM me, I'll give you the low down on exactly how I made it. I was skeptical, I even bought an online evaporative cooler. My cooler works twice as good.

Swamp coolers work where humidity is low, an AC unit works in any environment.

Regardless of what equipment you use it will need to drop the temps a great deal, and be able to do so for a prolonged period of time.

If you are able to, source cool outside air (it's getting to be that time in the northern hemisphere) it will reduce your cooling needs no matter what equipment you settle on.

Run your lights when it is coolest.

I'm not sure why the LED community has yet to get on board with ducting their fixtures to help remove the heat they generate. I believe this would to some measurable extent help folks who grow in tents as well as non-tent growers.

418 watts is what your light uses, it doesn't matter if it is a 418W LED or 400W HID, the heat output will be the same or slightly higher due to the extra 18W.

Almost nobody would run a 400W HID fixture uncooled in a tent the size you are using. I'm not saying this to insult your setup, just pointing out a reality that the entire LED world avoids like the plague. Watts used are watts used, and that directly translates into heat. Added heat in our world is not always a good thing, though I will admit to using my ducted HID lights to heat my house in the winter.

An evaporative cooler, be it DIY or otherwise, will add a measure of humidity, and that humidity must be removed from the plants environment or you risk all sorts of fun stuff like mildue, mold, and lower nutrient uptake if the humidity is high enough. It should be noted that as the humidity gets higher the evaporative cooling devices get less and less effective.

In my experience (which includes some pretty costly mistakes) going with a really good AC unit will save you some headaches down the road. Granted it will be more costly, but I doubt it will be as costly as a lost crop of home grown herb.

You might also consider only doing winter grows, I'm generally good for a year with a pound of bud in the jars and the few oz of sugar trim I get from a run under my 1k HID. I'll be super stoked if I ever manage 1g/W.

 

[Why Doe]

You cant grow in a closed closet with no ventilation and except not to have high temps lol......... Either you figure out some way to bring fresh cooler air in and exhaust the hot air, or get an ac unit. Literally the only 2 ways.

 

[TorturedSoul]

Re: Heat in my grow room is becoming a big problem...

I have lights on at night, temp with door shut can get as high as 35 but usually 30, closer temp is 21.

I can't keep door open because of the smell and I'm being stealthy with it hence in the closet

You have a tent inside a CLOSED closet. First, of course it's too hot in there. Second, either leave the door WFO when the lights are on or pull the tent out of the closet and stick it into a room with... some room. If your carbon filter is inadequate, try to get one that's properly sized for your grow space volume. Or it might be your fan. I've seen lots of sh!tty ones advertised as extraction fans. But put them under any kind of load, lofl... Could also be your setup. You need everything sealed from the filter on out, otherwise your fan is probably pulling stinky air through the cracks.

I'm not sure why the LED community has yet to get on board with ducting their fixtures to help remove the heat they generate. I believe this would to some measurable extent help folks who grow in tents as well as non-tent growers.

418 watts is what your light uses, it doesn't matter if it is a 418W LED or 400W HID, the heat output will be the same or slightly higher due to the extra 18W.

In practical terms, it's significantly worse. The majority of the LED grow light products on the market have their heat-generating power supplies inside the unit. Whereas, the (vast) majority of HIDs have remote ballasts (and the few that don't are easy to modify). Additionally, as you mentioned, all but a couple (AfaIK) LED products just blow the heat they generate right into the grow space with those dinky computer fans.

An air-cooled HID reflector... Well, if you really want to set one up correctly, you can run a separate duct/fan just for the HID. Which means the heat(ed air) doesn't have to go through your carbon filter. That's good because the run won't have that significant (if the carbon bed is decent) restriction. And it's good because you won't be running HOT air through your carbon filter, which means it'll both work more efficiently and last longer. And it's good because that air won't STINK, it'll just be hot air - blow it wherever the <BLEEP> you want to. And it's good because your general grow space air, being now significantly cooler, can be vented at a lower rate (or even sporadically instead of constantly). And it's good because... well, you get the picture.

BtW, they make insulated(+/-) covers for air-cooled HID reflectors, for people who want to do everything they can to keep the heat out of their grow. I'd guess that the people who use those also use insulated ducting on their runs for the portion (if any) that's inside the grow.

You could always get a portable air conditioner. But all the single-hose models are junk, lol. The double-hose models are a little better. Their BTU numbers are still pretty optimistic. And, hey, for the price of a decent one (such as a Whynter 14S... $450 to $525, last I checked for someone) you should be able to get a halfway decent HID setup, decent carbon filter, and extractor. You've got... a little over 7.1 square feet or so, so a 400-watt HPS would work, especially since you're growing auto-flowering plants in there and can run the thing for way more than 12 hours per day, boosting the DLI. If you were growing photoperiodic strains - and sativas, at that - I might suggest you go with a 600-watt one in that size tent (for around 84 watts per square foot of light), but you don't need it for your plants.

 

[alltatup]

The heat is going to become a much more serious issue for all growers. I find myself wondering where it will eventually become impossible to grow outdoors because of climate change. I'm strictly an indoor grower, but the heat has made my little hobby a much more expensive proposition than I anticipated.

I invested in solar panels a while ago to lower electricity usage and costs. With the tax credits given in the US, it was well worth the initial cash output. I also invested in two chillers for my two hydroponic gro boxes; root problems were chronic before I got the chillers.

 

[TorturedSoul]

The heat is going to become a much more serious issue for all growers. I find myself wondering where it will eventually become impossible to grow outdoors because of climate change.

Like 80% to 90% of the food crops that homo sapiens lives on are currently being grown in locations where - and consists of crops that - when the global averages jump ten degrees or so, will no longer be tennable... and you're worried about whether or not people will still be able to grow their smoke?

Well, f*ck, I'd be worried about it, too. After all, when you're starving to death, aint nothing a person wants more than a good buzz.

Or, you know... something to eat :icon_roll .

OtOH, Alaska ought to be warm enough to grow food AND cannabis. That's mostly permafrost now, up to what, 30' thick? So... what grows good in a swamp, lol?

 

[Guy Cavallero]

What I don't understand is why someone wouldn't try. I made a suggestion about the swamp cooler......did anyone try it? I have a sealed tent, beside my furnace in the basement. Last week the furnace came on and raised my temperatures significantly..... so I figured out a way to control them.....NO AC, NO OUTSIDE AIR......for the $40 it cost to make it, why not try it. Obviously pulling outside air in will cool things, that's not what Usernames asking. He's doing a stealth grow, last thing he needs to do is start cutting the drywall open in the closet to run pipes for cooling. If it doesn't work, do 2? Yes it will in crease humidity, but if you've already got high temps, RH in the 50-60 range isn't gonna hurt. Lights on at night, fans etc are all going to help.