Need advice from aussie growers about air con installation of a split system installation

i am building a grow box. for a 4 plant SOG personal use strictly under 2 600watt bulbs. probably will get the yield and will only have to do a cycle once every year or 2. I am really health conscious i work alot and like to train and keep fit this is the only way to know im not getting poisoned and ripped off.

the box sealed will have a grow area of slightly more then 2 meters square. i can get a small split system A/C that is 1.7kW from Mitsubishi from 600 dollars, so only slightly dearer then a portable air con, and its wall mountable and so forth, just feel like it will make the whole project finish a lot cleaner.



it is going to be lined with 7mm plywood that i will paint white with water proof paint and I will also be installing a door with a nice seal, intake out take fans, 2, 600 watters, sealing the gaps with silicone, except in 1 year i will be taking it down, and moving houses most likely, and will want to do this every 6 months over the next many years to come.

i need to finish the frame,and install framing wood where i am installing the door, and potentially the air con. although 7mm plywood will not be super strong but the unit itself is only 7kg and the bigger part of the split system on the outside is 25kg, so will most likely mount this to the outside.

i have a couple weeks to get this shit sorted out as plants are vegging really fast. but i am usually dodgy as fuck but really want to do a clean install that i can take pride in and have a nice job.

big questions that i need answers for LONG STORY SHORT:

1: My frame can be taken apart as i used bolts with nuts. and i am using screw inserts for the plywood so i can pull it down sort of like a grow tent and peel the silicone off that i use to seal and just reapply when i put it back together after bringing it out of storage, is a split system easy to take down and put back up once every 6 months for example ?

2: Will it be suspicious if i hire a refrigeration/AC technician to come and install it on my box and say it is for general hydro like indoor food and flower growing/legal hobby growing? (maybe i can watch them and ask a few questions about reinstalling after a move and so forth?

3: anyone know how to install a split system, will i need tools, how risky is it for a newbie, any good videos or guides for people like me? cheers.

AUSSIE insight would be great but will love anything i can get so please guys.

JoeRogan420 said:

is a split system easy to take down and put back up once every 6 months for example ?

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Nope, not unless you have the proper tools. You need to pump down the unit and reclaim the refrigerant unless it has a procedure for closing the liquid side of the line set and using the compressor to pull the charge back into the condenser unit.

JoeRogan420 said:

Will it be suspicious if i hire a refrigeration/AC technician to come and install it on my box

Click to expand...

Very suspicious

JoeRogan420 said:

anyone know how to install a split system, will i need tools, how risky is it for a newbie, any good videos or guides for people like me? cheers.

Click to expand...

At minimum you will need to connect the line set (and power / control wires) pull a vacuum on the line set and release the charge from the condenser unit (assuming it's new and factory charged). The best way to go is to use a nitrogen cylinder and regulator through your gauge manifold to pressure test the line set before pulling the vacuum. Tools include gauge manifold, 5/16 R-410a flare adapter, vacuum pump, optional (to do it right) nitrogen cylinder, torque wrench for the flares, nylog to seal the flares (very tiny amount on the front and back of the flare.

These are lots of youtube videos on servicing minis.

Installing a new unit without a licensed pro will void any factory warranty.

Renfro said:

Nope, not unless you have the proper tools. You need to pump down the unit and reclaim the refrigerant unless it has a procedure for closing the liquid side of the line set and using the compressor to pull the charge back into the condenser unit.


Very suspicious


At minimum you will need to connect the line set (and power / control wires) pull a vacuum on the line set and release the charge from the condenser unit (assuming it's new and factory charged). The best way to go is to use a nitrogen cylinder and regulator through your gauge manifold to pressure test the line set before pulling the vacuum. Tools include gauge manifold, 5/16 R-410a flare adapter, vacuum pump, optional (to do it right) nitrogen cylinder, torque wrench for the flares, nylog to seal the flares (very tiny amount on the front and back of the flare.

These are lots of youtube videos on servicing minis.

Installing a new unit without a licensed pro will void any factory warranty.

Click to expand...

Do you think it is worth the investment in the tools such as vacuum pump and things needed? Or just go with a portable AC for the time being..

And in the future save up for the tools and play around with cheap 2nd hand splits until i am confident to buy one and do it myself.

Another issue is i think split systems need to be wired in to a main. I dont know electrical stuff only auto electrics and am not a whizz.

Is there many splits that plug in to a power point.

Im leaning towards a portable AC for this sealed room..

Renfro said:

Nope, not unless you have the proper tools. You need to pump down the unit and reclaim the refrigerant unless it has a procedure for closing the liquid side of the line set and using the compressor to pull the charge back into the condenser unit.


Very suspicious


At minimum you will need to connect the line set (and power / control wires) pull a vacuum on the line set and release the charge from the condenser unit (assuming it's new and factory charged). The best way to go is to use a nitrogen cylinder and regulator through your gauge manifold to pressure test the line set before pulling the vacuum. Tools include gauge manifold, 5/16 R-410a flare adapter, vacuum pump, optional (to do it right) nitrogen cylinder, torque wrench for the flares, nylog to seal the flares (very tiny amount on the front and back of the flare.

These are lots of youtube videos on servicing minis.

Installing a new unit without a licensed pro will void any factory warranty.

Click to expand...

Any idea on what size air con for 1200watt hps in a 2.4 meter squared area thats the size of the box when its finished..

If you buy a used mini split you will need to purchase refrigerant and weigh in a proper charge. That would also require a set of HVAC scales and a gauge manifold, liquid low side charging adapter and a 5/16 adapter. Really it's a lot of tools and knowledge that is required to service them. I do all my own because I can't wait for a tech (it's legal to grow here).

Tools to do proper work:

Gauge manifold with hoses (don't get cheap shit)
Vacuum pump
Nitrogen cylinder w/ regulator
Liquid Charging Adapter
5/16 - 1/4 flare adapter
Refrigerant reclamation pump
Refrigerant reclaim tank
Refrigerant Scales
Torque Wrench

Go watch some youtube videos on servicing these units.

Jaybeeee123455 said:

Any idea on what size air con for 1200watt hps in a 2.4 meter squared area thats the size of the box when its finished..

Click to expand...

Probably the smallest mini you can find... Half a ton would do it unless the box is sitting in a really hot garage...

Renfro said:

If you buy a used mini split you will need to purchase refrigerant and weigh in a proper charge. That would also require a set of HVAC scales and a gauge manifold, liquid low side charging adapter and a 5/16 adapter. Really it's a lot of tools and knowledge that is required to service them. I do all my own because I can't wait for a tech (it's legal to grow here).

Tools to do proper work:

Gauge manifold with hoses (don't get cheap shit)
Vacuum pump
Nitrogen cylinder w/ regulator
Liquid Charging Adapter
5/16 - 1/4 flare adapter
Refrigerant reclamation pump
Refrigerant reclaim tank
Refrigerant Scales
Torque Wrench

Go watch some youtube videos on servicing these units.

Click to expand...

Alot of tools. I think this is a project i will save for and look into down the track. Thanks alot bro. I have watched a few it doesent seem too difficult. But i only have a 3 grand budget more like 2 grand would be ideal.. so to stick to the 2 grand ill probably get a portable AC. One day when i buy my own house i might even be able to get a pro to install a AC for me without it being so suspicious.

Renfro said:

Probably the smallest mini you can find... Half a ton would do it unless the box is sitting in a really hot garage...

Click to expand...

And yeah smallest one is 1.7kW not sure how many BTU's that is but its small.

Portable vs mini split is about the same price. It annoys me because i feel like a mini split would be much better... im sure ill.be okay though i just really want to do a good job

This look okay? I might buy portable and get these tools and slowly work on this project for.the future

Jaybeeee123455 said:

Vacuum Pump and Manifold Kit. Refrigeration & HVAC split Installations

Quality refrigeration service tools and vacuum pumps at competitive prices, online and direct with express shipping. Heating, ventilation, and air conditioning service tools from Imperial, JAVAC, TPI and Phasefale direct to the engineer.

hvacdirect.com.au

This look okay? I might buy portable and get these tools and slowly work on this project for.the future

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Not sure about the quality of the manifold but it will probably do the job.

Is the box located inside a home that has central air?. I mean 2 x 600s are pretty easy to cool with ventilation. I always find it easier to control smell when venting as well because you can keep negative pressure on the grow space and make sure all the air is exiting thru a carbon filter.

If you don't have central air your next best bet is to just put a window unit in the room your grow box is going to be in. So that you have cold air coming in.

Or you could go with a portable they are mostly junk for dealing with any kind of real heat but 2x600 watts would prob be find as long as you got a decent unit. Smell can be an issue with these units tho.

Just thought about something else isn't it winter in Australia now or about to be. What is your avg outside temp now. Since you say your only going to be growing here and there plan to run in winter if temps are low enough can get by without any ac

Apalchen said:

Just thought about something else isn't it winter in Australia now or about to be. What is your avg outside temp now. Since you say your only going to be growing here and there plan to run in winter if temps are low enough can get by without any ac

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Its in a garage it gets to like 30-35 all summer.
And maybe 20 - 30 all winter.

I dont have a window to mount it on. At least with the portable one i can very easily mount the exaust heat and try and duct the cold air into the bottom of the tent.

I will also have 2 adjustable fans and maybe even a fan for the 2 cool tube hps/mh lights.

So ventilation fans, carbon filter, cool tubes, and a portable ac.

Thing is i want my temps at the exact correct temperature of what is the best like 22 degrees?

I want the environment to be fully dialed in no dodge half ass jobs

Apalchen said:

Just thought about something else isn't it winter in Australia now or about to be. What is your avg outside temp now. Since you say your only going to be growing here and there plan to run in winter if temps are low enough can get by without any ac

Click to expand...

Renfro said:

Not sure about the quality of the manifold but it will probably do the job.

Click to expand...

I will be saving for the tools. Perhaps even good quality tools. So i can play around and get familiar with the split system installation and tear down and reinstallation and figure out my limitations and stuff and see if i can make it work.

I just have it in my head that a split system is much better quality then a window or a portable ac. Will be more energy efficient and efficient and will help me get a more dialed in enviroment..

Want a spot on environment 22 to 25 degrees celcius

Jaybeeee123455 said:

Thing is i want my temps at the exact correct temperature of what is the best like 22 degrees?

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79F is perfect for non CO2 enriched HPS grows. 83 - 85F tends to work better with LED grows that are lacking the abundant infrared spectrum that HPS provides.

CO2 enrichment will require a little warmer temperature to accelerate the plants metabolism so it can actually use the higher CO2 levels. This also means more light and more food/water. It's a balancing act indeed.

It will be VERY difficult to get an exact temperature as thermostats have a designed dead band to prevent short cycling the equipment. An air conditioner that is way oversized for example would have to shut off and turn on very often. A minisplit with it's inverter technology is capable of running at different speeds (compressor and fans) so it's not just ON or OFF like most AC units. This can allow a user to find a setting that holds the room pretty darn close using the"auto" settings. For this reason a minisplit can be oversized without short cycling becoming an issue.

Jaybeeee123455 said:

I just have it in my head that a split system is much better quality then a window or a portable ac.

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It is better, but your area is on the small side.

Know that you cant charge a mini by reading the gauges as you can with say an R-22 system. Some units have a dip switch mode that will facilitate this but really the recommended way to see if the charge is low or needs to be added is to pump down the unit weighing out the charge. If it is supposed to have 148 ounce charge and you only pull out 120 ounces then it had a leak. After pulling the unit down (weighing out the old charge) you can weigh in the proper charge. With other AC types (non inverter) you can read the pressures and determine if the charge is low and add refrigerant until the pressures are within spec.

So in short, servicing these can be a little more complicated and time consuming and require more tools than other systems.

For such a small grow I don't see it being wise to invest in such tools as a recovery pump, refrigerant scales, recovery cylinder. If you plan on servicing more units or expanding the grow, or if it's mission critical income and you can't wait for a tech or if growing is illegal and you can't have a tech come around then learning to do this yourself and owning good tools is the way to go.

Also note that you may have a difficult time obtaining refrigerant without a license.

Renfro said:

For such a small grow I don't see it being wise to invest in such tools as a recovery pump, refrigerant scales, recovery cylinder. If you plan on servicing more units or expanding the grow, or if it's mission critical income and you can't wait for a tech or if growing is illegal and you can't have a tech come around then learning to do this yourself and owning good tools is the way to go.

Also note that you may have a difficult time obtaining refrigerant without a license.

Click to expand...

Damn. I guess i will have to wait until i get my own house before i can get one professionally installed and can be there and never have to be moved.

So im thinking ventilated grow at the moment is fine with a portable AC.

But if the next grow i decide to try a sealed grow can i use a portable AC and duct the cold air in from the outside ?

With it being a sealed box with only cold air coming in from a portable AC wouldnt this make it a positive pressure and be hard to push air into the sealed room.

How does a mini split work in a sealed room if it is sealed how can it push air in if air cant get out. Wouldnt it be a massive positive pressure that would try and force its way out through cracks?

Jaybeeee123455 said:

Damn. I guess i will have to wait until i get my own house before i can get one professionally installed and can be there and never have to be moved.

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Probably the way to go. You could bone up for the Mr. Cool style units that have pre charged quick connect linesets. They are pricey. I haven't any experience with them personally.

Jaybeeee123455 said:

With it being a sealed box with only cold air coming in from a portable AC wouldnt this make it a positive pressure and be hard to push air into the sealed room.

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Typically the sealed box would be constructed of such dimension the portable (dual hose unit) sits inside the box and the hoses for the condenser coil go out. Otherwise your box will be unsealed indeed as you would require a passive vent or connection to the portables return vents.

Jaybeeee123455 said:

How does a mini split work in a sealed room if it is sealed how can it push air in if air cant get out.

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The minisplit is in the room, pulling air from there and blowing it back in there. Only the refrigerant goes outside.

In a sealed room you will need to provide CO2. Probably dehumidify as the plants get big, especially when lights are off.

Gets complicated when you go sealed. You have to get a good environmental controller, a CO2 tank and regulator or a CO2 generator and run NG/LP gas. You need to manage humidity even more when sealed, as biomass increases it gets more difficult. Of course we don't want high humidity when the plants are big and have flower to mold. So yeah, there is a lot more involved when you go to a sealed room.