Question on a minisplit?

[MountainBudz]

I am fixing to pull the trigger on a 24,000 btu mini-split AC/heatpump today. I likely won't be able to get my co2 burner for another couple of weeks. Is it fine to run sealed until I can get the burner, without using co2? Like if I exchange fresh air every so often? And if yes, then how often shall I exchange the air? I am 3 weeks in flower right now and the temps are just getting ridiculously high and I feel its better to go head and put in the AC without co2 for a another couple weeks till i can afford the burner.

Also, while I am at it, would a 4 burner be sufficient for a 4,000 watt grow? 17ft x 6.5ft x 6.5ft? And what brand would you recommend? I am looking at Titan controls.

The mini split I am getting has excellent reviews on amazon and it is a Pioneer Air and pretty decent price as well. Thanks to anyone that can answer my questions!

 

[bigtacofarmer]

You are going to need fresh air

 

[MountainBudz]

You are going to need fresh air

Yes I know.

That is why I asked, if until I can get my co2 burner how often should I sit the intervals on my timer to bring in fresh air and exchange and for how long during the exchange should I be pulling in that fresh air is the question?

I mentioned knowing that I needed fresh air in my OP, just how often and for how long each time is all I need to know... I am setup to pull fresh air in already. Thanks.

 

[Granger2]

Calculate how many cu ft, and run intake long enough to move that much air. How long? I can't say. Remember that most people shut off CO2 during late bloom. Seems to me that once an hour should handle needs for late bloom. When you get your burner, set it to about 400 ppm till harvest. Good luck. -granger

 

[MountainBudz]

Calculate how many cu ft, and run intake long enough to move that much air. How long? I can't say. Remember that most people shut off CO2 during late bloom. Seems to me that once an hour should handle needs for late bloom. When you get your burner, set it to about 400 ppm till harvest. Good luck. -granger

Only 400 ppm? Most things I have read are recommending more like 1200 ppm. But yeah, I would say bringing fresh air in about every hour, in 5 min intervals per each hour should be sufficient.

But, would the air from the mini-split not be fresh air though? Just thought about that.

Edit: or are you only recommending that ppm since I am already in mid flower...? If that's the case, im confused how this whole co2 thing is gonna work out for me. Reason being, I run a staggered perpetual. I have some in mid flower and some just went in the flower room yesterday... uh oh. What shall I do? Wonder if I can even benefit from co2 growing this way?

 

[oti$]

I've been seeing co2 less and less in grow rooms in the past few years with more perps going for major air exchange. Ive heard that peeps benefit more in veg from co2 than flower, but I have no direct experience as I typically use a lung room and exchange 2x per minute, which helps with heat in addition to cool air. Where is your veg in relation to your flower room? Maybe you could exchange enriched air between veg and flower. I understand that if you are running fully sealed rooms you'll definitely need co2 enrichment. How much fresh air are you bringing in before the mini,,split install? Granger has always been helpful with sharing information and experience so maybe he will elaborate on the co2. I believe I've read that canna plants don't benefit after 800ppm, but as I said, I have no direct experience...

 

[Wendull C.]

Just exchange your air 2 to 4 times an hour. You will be fine until you get your burner

 

[Shmavis]

If you haven't already, get yourself a CO2 meter/monitor. You just may be surprised at the ambient readings. I know I was. Use cubic feet for your sizing. I have a GAP CD-6 for roughly 750cuft.

Also have read that above 900ppm is wasted. I also think that 'sealed' usually refers to climate controlled with CO2 supplementation. Not including an external air exchange — sealed. But of course many ways to skin a cat. And variations of versions.

If you get a meter and find ambient readings above 700, I'd go with DHF's recommendation (same as oti$) of twice per minute air exchange, given you can cool the room with only air exchange, it's worth testing before investing. Meaning a lung room might be a better option. And cheaper.

In a multi-strain garden (or even perpetual mono-cropping) with elevated ppms you will find maturation times are later.

Interested to hear how you go about this and what you find. I have been on a CO2 experiment for the last, at least, couple years... and starting to lean towards zero supplementation, instead incorporating a lung room; which then if needed may find the generator in there.

Good luck!

 

[Granger2]

I've never tried perpetual because of the complications, one of which is the CO2 thing. Ambient CO2 [outdoors] is about 400 ppm. So I suggested maintaining 400 from mid bloom on because I believe it's best to, at that point, stop adding extra CO2.


During veg and early bloom I take it up to about 1000 ppm till [in my sealed room] I cut that to about 400 till harvest.

 

[Shmavis]

I snapped this pic as soon as I entered my room, at about an hour after the light came on. Within five hours (if I haven’t been in the room or the basement itself) it will drop between 200 to 300ppm. This is with zero enrichment.

You’ll need a controller for the generator, if you get one. I’d grab the controller now and have it run your air exchange. Just set the desired ppm and let it take the guess work out of the rate of exchange. It would be inefficient, exhausting conditioned air, but as long as the desired ppm level doesn’t have the exchange happening on a continuous cycle, it might get you through.

Are you sure 2 tons is enough for 4k? With additional BTU from the generator and dehumidifier... and ballasts in the room too? (My 6 burner is 4400 BTU)

Here’s a link to the controller I bought, which at the time was the cheapest one I found (thanks to DTS) and I have checked its accuracy against a monitor. Solid purchase. It can also be setup to run an exhaust for high CO2 levels.

https://www.co2meter.com/collections/agriculture/products/day-night-co2-monitor-controller

 

[MountainBudz]

I snapped this pic as soon as I entered my room, at about an hour after the light came on. Within five hours (if I haven’t been in the room or the basement itself) it will drop between 200 to 300ppm. This is with zero enrichment.

View Image

You’ll need a controller for the generator, if you get one. I’d grab the controller now and have it run your air exchange. Just set the desired ppm and let it take the guess work out of the rate of exchange. It would be inefficient, exhausting conditioned air, but as long as the desired ppm level doesn’t have the exchange happening on a continuous cycle, it might get you through.

Are you sure 2 tons is enough for 4k? With additional BTU from the generator and dehumidifier... and ballasts in the room too? (My 6 burner is 4400 BTU)

Here’s a link to the controller I bought, which at the time was the cheapest one I found (thanks to DTS) and I have checked its accuracy against a monitor. Solid purchase. It can also be setup to run an exhaust for high CO2 levels.

https://www.co2meter.com/collections/agriculture/products/day-night-co2-monitor-controller

Great info Shmavis...

I can only hope it is efficient, considering I have the 24,000 BTU mini split already out for delivery on a freight truck. I emailed Titan Controls and explained my setup and they said it should be fine. But we shall see... if all else fails, I will throw a window unit in the room to push out a little more help. I do have a lung room (the hall) between the grow area itself anf the outside wall. I also planned on opening my hoods and not air cool the lights. I had heard that 24k btu was more than enough for 4000 watts but we can only find out when she gets here. I planned on having the outside unit of the split in my lungroom, putting it outdoors outside of my grow area would definitely draw unwanted attention and most definitely paranoia.

 

[Medfinder]

as far as mini splits...

up to 28 seer some pricy wifi carrier models.

knock offs may be hard to find parts for.

have u looked at ceiling cartilage mini splits yet?

 

[Shmavis]

Great info Shmavis...

I can only hope it is efficient, considering I have the 24,000 BTU mini split already out for delivery on a freight truck. I emailed Titan Controls and explained my setup and they said it should be fine. But we shall see... if all else fails, I will throw a window unit in the room to push out a little more help. I do have a lung room (the hall) between the grow area itself anf the outside wall. I also planned on opening my hoods and not air cool the lights. I had heard that 24k btu was more than enough for 4000 watts but we can only find out when she gets here. I planned on having the outside unit of the split in my lungroom, putting it outdoors outside of my grow area would definitely draw unwanted attention and most definitely paranoia.

Sounds like you’re dotting i’s and crossing t’s. And I agree, it’s a go-by-feel process, any time we make changes/improvements to our rooms - theory often doesn’t agree with reality. I too would try running open hoods to start. If you’re also set up to switch quickly to air cooled then no reason not to test her ability to handle the heat load. Is the compressor running in the lung room factored in to the 2 ton rating?

 

[MountainBudz]

Sounds like you’re dotting i’s and crossing t’s. And I agree, it’s a go-by-feel process, any time we make changes/improvements to our rooms - theory often doesn’t agree with reality. I too would try running open hoods to start. If you’re also set up to switch quickly to air cooled then no reason not to test her ability to handle the heat load. Is the compressor running in the lung room factored in to the 2 ton rating?

I am pretty sure it is 2 ton, 15 seer.

 

[Shmavis]

Looking forward to hearing how it goes for you. Please let us know. I am still going back and forth over a mini.

 

[oti$]

How or you going to exhaust the heat put off by the condenser that you are planning on keeping in your lung room?

 

[Shmavis]

How or you going to exhaust the heat put off by the condenser that you are planning on keeping in your lung room?

Not to mention providing proper air exchange for the condenser... If the condenser is in a closed-loop with the mini's head unit, that's a substantial extra workload being put on the mini... unless the lung room is independently controlled... or so I would think, but I am pretty high right about now...

 

[MountainBudz]

Hmm I am not sure. My lung room has two 8 inch holes. One on the far left side of hall which currently the fresh outside air is feeding through duct into my grow op and then the other is located on the opposite far right side where my heat is exhausted. Since the grow room itself will be sealed once I get the split, I guess I could put an exhaust fan in one of those holes pulling or pushing hot air out of the lungroom to the outside while it will passively pull outside air in through the other hole?

 

[MountainBudz]

Its like this... outside > concrete wall > lungroom > wall >growroom.

 

[oti$]

The condenser will heat up that lung room substantially...you could put it outside and build an enclosure with an open top to let the heat out. From a distance no one would know what was inside...