Considering adding CO². Is it possible to run without mini split (using a single LED light - Optic Slim 720S)?

[SunriseSkunk]

So as the title suggests. We're looking at (one day - not yet) perhaps installing a CO² system.

Our grow room is small, 6x8x8. Only growing 4 plants. And is sealed up fairly well (but will seal up the last bit before this work is done. We get negative pressure with fans and it sucks the door shut when it's close, so should be good already lol).

Is it possible for a single LED (Optic Slim 720S) light to bring the rooms temperature up to for example (because we haven't actually measured this yet) 95°f by the end of an 18 hour light cycle (auto flowering) then use the intake & exhaust fans in the evening (and shutting down the CO² also).

We know that it should get up to about 85-86°f-ish in there with the circulation fan going over the top of the light/driver.

Basically - is anyone else out there gassing without having to install an additional cooling unit on your home? (we literally just had a large multi level mini split heat pump installed recently and if we can avoid another one that would be just nice on the wallet).

The grow room is in the basement where it is already air conditioned with the existing mini split, so pulling in nice, cool air in the evenings wont be a problem.

 

[BigBlonde]

I am not familiar with that light, but I do know that LED lights can significantly warm a growing space. My ViparSpectra XS2000 can push my 2x4 tent temperature above 90F quickly if the fan isn't running. I have an AC Infinity controller for the fan with a 77F trigger. The fan also has a 60% relative humidity trigger. Temperature and humidity have an inverse relationship. We have a mini split in our home, too, and that keeps the humidity low. It's usually below 50% and it's 40% now because the outside temperature is below freezing. Sometimes, that's too low so I have a humidifier in the tent.

 

[Zill]

CO2 fertilization. Yup, increasing CO2 ppm can increase the rate of photosynthesis and as a side benefit dramatically reduce photorespiration. But, not all plants respond positively to higher CO2 and other factors can become limiting such as N2 as photosynthesis rages on.

 

[SunriseSkunk]

So as the title suggests. We're looking at (one day - not yet) perhaps installing a CO² system.

Our grow room is small, 6x8x8. Only growing 4 plants. And is sealed up fairly well (but will seal up the last bit before this work is done. We get negative pressure with fans and it sucks the door shut when it's close, so should be good already lol).

Is it possible for a single LED (Optic Slim 720S) light to bring the rooms temperature up to for example (because we haven't actually measured this yet) 95°f by the end of an 18 hour light cycle (auto flowering) then use the intake & exhaust fans in the evening (and shutting down the CO² also).

We know that it should get up to about 85-86°f-ish in there with the circulation fan going over the top of the light/driver.

Basically - is anyone else out there gassing without having to install an additional cooling unit on your home? (we literally just had a large multi level mini split heat pump installed recently and if we can avoid another one that would be just nice on the wallet).

The grow room is in the basement where it is already air conditioned with the existing mini split, so pulling in nice, cool air in the evenings wont be a problem.

Side note: we would also like to note we do have a commercial Dehumidifier (Alorair Sentinel 55) hung in one of the upper corners (above the permanent light height) that drains into a condensate pump which then ejects down a wash sink.

Currently however we're unsure how much warmer this device will make the air, as our extraction fans (6" AC infinity intake + carbon filter & an 8" AC Infinity exhaust + carbon filter set to 8 on the "ON" setting - which is constantly on at speed 8 with no special triggers) and lung room (basement) is kept at optimal temperature & humidity (because of the existing mini split & additional existing Waykar brand home Dehumidifier) - currently flowering week 3 with 1.2VPD @ 74°f/52%RH (Basement Dehumidifier is set to 55% and the mini split is set to 60°f).

We assume this device (the Alorair Commercial Dehumidifier) would raise the temperatures by approximately 10°f or so but that's 100% guessing at this point haha this is where we got the initial 95°f from.

 

[Zill]

Sunrise,

Question: The dehumidifier condensate is sent to drain. The condensate is distilled water and you have invested money in that waste. Have you thought about using the distilled water amended with all the plant nutrients and use that to feed?

 

[SunriseSkunk]

Sunrise,

Question: The dehumidifier condensate is sent to drain. The condensate is distilled water and you have invested money in that waste. Have you thought about using the distilled water amended with all the plant nutrients and use that to feed?

Dehumidifier water is not recommended. Potential for waterborne pathogens.

We live on an island in Canada and have unlimited access to very fresh clean water. However we do use city water and dechlorinate that as we'd rather not be hauling water and putting unnecessary mileage on our vehicle. The more time spent at home (or not used on garden labor as such) the better.

We do also have our own 30L water / alcohol Distiller. But to constantly be distilling water is just as inefficient as traveling and spending gas / maintenance than it is to just turn on the tap, that's then dechlorinated. Proper water on demand is a must. This device is reserved for making high proof, all natural ethanol, used to make extractions.

Edit: also even if the water was clean there wouldn't be enough collected overall and still need to supplement with additional water. So better off using ALL clean water. Then something that could be questionable.

 

[Anthem]

Sunrise,

Question: The dehumidifier condensate is sent to drain. The condensate is distilled water and you have invested money in that waste. Have you thought about using the distilled water amended with all the plant nutrients and use that to feed?

Yes but there is also residual manufacturing materials that come along with the water that makes this a bad idea.

 

[NorthernOrganics]

In my experience, sealing a room is going to require some sort of cooling. Watts are watts, that light is going to put a certain amount of heat in the air the whole time it's on. If you aren't extracting the heat or cooling it down, it's going to get out of hand in a sealed room. I run tents in a lung room with dehuey right now, only about 300 watts of light, and my room gets up to 90 sometimes. I would look into a controller for your fans and CO2 that will trigger extraction at temp/rH setpoints. Also, dehuey water isn't pure distilled water, it will have higher mineral content, usually copper from the evaporator coils.

 

[Scotty420]

You could just use a portable AC unit that ducts the warm air into the basement room cooled by the mini split. This would cost a fraction of having a new mini split installed.

 

[BigBlonde]

Sunrise,

Question: The dehumidifier condensate is sent to drain. The condensate is distilled water and you have invested money in that waste. Have you thought about using the distilled water amended with all the plant nutrients and use that to feed?

I tested the pH of the distillate from my dehumidifier and was surprised to find that it is rather low. I would have predicted it would be near 7, but it was close to 5. I found an explanation somewhere out there in the Internet machine. That was this: The distillate combines with CO2 in the air to form carbonic acid. So, I would advise testing the pH of the distillate before use, and adjusting it if necessary.

 

[BigBlonde]

Currently however we're unsure how much warmer this device will make the air

That, I have found, depends to a significant degree (pun intended), on the season and the weather. Sometimes, additional heat is welcome. Sometimes it is not.

Also, I can see a bump on the temperature record when the dehumidifier in my lung room runs. It returns to normal rather quickly, though, because other systems, like fans, are controlled by sensors that adjust automatically. I would say that what should definitely be avoided is two systems in conflict, like a heater and A/C with overlapping settings.

 

[Scotty420]

So you got me curious, I have HVAC load calculation software that I use for work. So I ran your grow room through it. Assuming it isn't built on an exterior wall of the house (and even if it is, if it's a basement that won't really add to AC load unless it's a walkout) you should need 2,600 btu with nothing in it. (130% of actual load) However that's also probably more than you really need because 30% of that load is actually latent heat (humidity) which could be removed by your dehumidifier, making the AC's job easier. Also plant humidity should be covered by the dehum as well so we shouldn't have to account for that.

Obviously you have lights, but that's actually easy to figure. Each LED will generate 3.14 btu per watt (ironically the same amount of heat per watt from electric heat). Looks like your light is 720 watts so a max of 2,455 btu's from lights. So at most you would need 5,000 btu. The smallest unit I've ever seen (outside maybe a window unit) is 9,000 btu or 3/4 ton. However your dehumidifier should take care of any oversizing issues.

 

[IamN2pot]

Let me chirp in here with some good infor for you from Dr. Bugbee in an inteview with Shane from Migro. The CO2 talk starts at the 46 min mark, but watch the whole video. It's full of good, scientific info on growing medicinal marijuana! Hope it helps you.

Best Grow Lighting for Cannabis with Dr Bruce Bugbee | Far red ePAR

A complete guide to the best grow light spectrum and PAR intensity for cannabis with scientist Dr Bruce Bugbee, Founder of Apogee Instruments and professor a...

www.youtube.com

 

[SunriseSkunk]

You could just use a portable AC unit that ducts the warm air into the basement room cooled by the mini split. This would cost a fraction of having a new mini split installed.

We considered this. However our thought process was as follows - wouldn't the exhaust also ventilate the CO²?

Also would the cost one less (overall) for a mini split? We're not sure how to calculate this even if it wasn't ejecting CO² haha. We used to use an AC in our home before and our eBill rose by approximately $90.00CAD a month lol. Don't think that was a very good unit though? Not sure. Not very educated with hvac. However the mini splits are the cats ass haha.

 

[SunriseSkunk]

Let me chirp in here with some good infor for you from Dr. Bugbee in an inteview with Shane from Migro. The CO2 talk starts at the 46 min mark, but watch the whole video. It's full of good, scientific info on growing medicinal marijuana! Hope it help you.

Thanks, loves me some Dr. Bugbee and Shane videos. Haha.

Learned a fair bit from them bought that Bluetooth par meter that Shane recommended.

 

[IamN2pot]

Learned a fair bit from them bought that Bluetooth par meter that Shane recommended.

LOL, that's the one I use.....

 

[Scotty420]

We considered this. However our thought process was as follows - wouldn't the exhaust also ventilate the CO²?

Also would the cost one less (overall) for a mini split? We're not sure how to calculate this even if it wasn't ejecting CO² haha. We used to use an AC in our home before and our eBill rose by approximately $90.00CAD a month lol. Don't think that was a very good unit though? Not sure. Not very educated with hvac. However the mini splits are the cats ass haha.

Just get a 2 hose version. It will have an intake & exhaust hose that will both go into your other basement room. It will pull air from the other room to cool the condenser coil & exhaust it back into that room. No CO2 should escape. And yes mini splits are awesome, but expensive to buy/get installed. Here's an example of what you can get a portable AC for vs a mini split, no installation needed other than cutting in the vents.

https://www.amazon.com/Whynter-ARC-...s=portable+ac+dual+hose&qid=1677173479&sr=8-3

For cost comparison here's a same sized mini split that will need a pretty considerable amount of installation.

https://www.amazon.com/MrCool-Ductl...4717ed486b994&language=en_US&ref_=as_li_ss_tl