Diy Mr Cool Mini split

[Itsmychoice]

I have had good luck with several diy mr cools. Mini splits are very efficient and the best bet would be to cool the garage the tent is in and exhaust air in the tent into the garage to cool it. A 12k btu would do it and won’t add much to your power at all. Plants do good with the heat until the last part of flower.

 

[Ca++]

I have had good luck with several diy mr cools. Mini splits are very efficient and the best bet would be to cool the garage the tent is in and exhaust air in the tent into the garage to cool it. A 12k btu would do it and won’t add much to your power at all. Plants do good with the heat until the last part of flower.

Why are you cooling the air leaving the tent? And the garage, which is a difficult to calculate heat load. It could be baking in the sun with no insulation.
Cooling the air leaving, indicates you want to use it again. Meaning more heat load from dehumidifiers. CO2. However he doesn't want a sealed room.
I don't know what you are doing.

I have a 12,000 btu unit here, which is about 3000w of cooling. It's taking in 28c air and delivering 13c air. It's coming out with some gusto. However I'm not sure the OP needs aircon at all. How hot can it be outside. Presuming he can get some.

 

[Three Berries]

My central air for the 1000 sq ft house is 2 ton/24kBTU. And it still too big.

 

[Itsmychoice]

I have no idea about his exact scenario but he was asking about air conditioning. Pulling fresh air from outside is great except it doesn’t allow for controlling humidity. Having the tent in a cool air conditioned dry garage is the way, and exhausting the hot air out of the top of the tent into the room with a low intake of course will keep the tent at an ideal temp and humidity. Certainly i would insulate the garage if i was adding air conditioning

PS I am just trying to help the fellow grow good cannabis in case what I am doing becomes unclear to you again

 

[Ca++]

He knows an aircon can cool things. He needs a plan of action with numbers attached. As with any install, the inlet plenum is where you treat the air. Lung room as many call it. Treating the exhaust is confusing. I know about hvac, and can't figure out your plan.

The sun beats down on my place. The 12,000 is OK for a room. It's 10pm and inside is just a bit warmer than outside. The thermal gain from my building is so high.

It's simple enough as we know. We need to know the volume of air going in, and the temperature drop required to get into range. Then it's still suck it and see. Outside conditions are not fixed. Temperature or RH. Which move independantly of each other. In a high RH area, you might size the aircon to run a bit cooler than perfect, as it offers more de-humidification. You may need so much dehu~, that you still add a separate dehu~ to both dry the air, and put a bit of heat back into it. The weather channel can offer averages over many years. It's more likely the outside air RH is fine, and using aircon will over dry it. That's the best scenario as a humidifier on a stat can then keep you just right all the time. Without expensive kit that's not very flexible in operation. We tend to use a humidifier on constantly to cover 75% of the need, and a second on a stat for the last 25%. So the RH doesn't crash the moment the stat clicks off. The same with heaters. You install trace heat, and then thermostatic to compliment each other.


My aircon is mobile. Big pipe out the window job. TB's is a split. As mine runs, it acts as an extractor. Pulling air into the room from outside where it's hot. The split doesn't extract, pulling in more air to treat. The mobile puts extra demand on the outside inlet, as the inlet must supply the tent + the mobiles extraction need. The mobile will be sucking air back out the tent given chance. A split won't experience this problem. Giving the tent extractor an easier job.


It does need a bit of thinking about. Plants probably grow outside though. So outside air is fine. Usually.

 

[Itsmychoice]

I can’t tell if you are joking, but good luck.
OP don’t buy a portable ac and don’t be convinced you can grow dense flowers at high temps. Peace

 

[Ca++]

I still don't hear what you are trying to do. Not even which direction the air is going. All I do hear is senseless. As an example, why is being able to move your AC a problem. Being fixed is a greater problem for self install. What is high temperature. What have you actually come up with. That an aircon can cool a garage? That's ground breaking that. I can see him rushing out to do what exactly?

This is how to do it. Size the aircon to dry enough, even on the damper days. Then use a humidifier to raise the RH on the dryer days. Temperature is of secondary interest imo. You just need the aircon to run continuously. Though the EC screw compressor models are changing that, with there variable output. An aircon might not be needed in reality, but the idea is treat the air coming in, then get rid of the high RH, High temperature air coming out. The idea of trying to recondition the used air is crazy if it's not a sealed room.

What you got joker, this?

This needs a 25 gallon per day water extraction ability. More electric than the lights. Before you start cooling anything. Which is now your lights, your dehu and the solar gain of the garage. You are getting yourself in a mess.
I'm not surprised you don't get what I'm talking about, but trying to shut the conversation down with impudent comments does you no favours.

 

[CertifiedRefugee]

Iam just trying to find a way to cool a 10x10x7 grow tent that's 700sf with two DE hellion with super spreader with a two 10" ac infinity fans for exhaust and also two 6" ac infinity fans for intake
'i have no basement no garage jus too spare bedrooms i also rent trying to do the least amount of damage to the property as i can and i like the idea of adding a mini split to it but i don't like having to uninstall it when i move i was thinking there was a another alterative

 

[Itsmychoice]

You could hang the mini split on the wall, make a plug for it and run the line set out the window and set the condenser on the ground. The diy line sets use quick connects and it would be easy to take down and with you when you move. I have moved them several times. Mini splits are much more efficient and quieter than portable units.

 

[CertifiedRefugee]

You could hang the mini split on the wall, make a plug for it and run the line set out the window and set the condenser on the ground. The diy line sets use quick connects and it would be easy to take down and with you when you move. I have moved them several times. Mini splits are much more efficient and quieter than portable units.

thanks... would the plug be consistent just like building a plug and play light controller ? View attachment 18743922 View attachment 18743923 like this?

 

[CertifiedRefugee]

or jus buy a 110v mimi split?

 

[Itsmychoice]

Yeah it will be easy just get the mini split at the right voltage, 120v to plug into an existing outlet in the room. Make one for the condenser also, try to plug them into outlets on different breakers. I have used 12 gauge extension cords cut to length leaving the nice factory plug and wiring in the cut side. When you mount the inside air handler unit keep in mind the lineset, follow the directions and get the distance to the condenser just right.

 

[CertifiedRefugee]

Yeah it will be easy just get the mini split at the right voltage, 120v to plug into an existing outlet in the room. Make one for the condenser also, try to plug them into outlets on different breakers. I have used 12 gauge extension cords cut to length leaving the nice factory plug and wiring in the cut side. When you mount the inside air handler unit keep in mind the lineset, follow the directions and get the distance to the condenser just right.

gotcha...

 

[Ca++]

Could of sworn you had a garage. That's some heat lost at least.

Two bedrooms, using one?
Dry wall? Back to back sockets or light switches sharing a cavity? They offer a route for the umbilical cord.

I best check you have 3000w... so many threads.
3000w is 1200btu, and your aircon will use 1200w to shift that. Regardless of if it has wheels or not.
I have a bit of a puzzle myself. Lets say your lighting is 33% efficient. It creates 2000w of heat directly. 1000w goes to light, not heat. Some of that light creates heat though. Which I can't apportion.

Will you be taking air in off the landing/hallway? As conditioning it there might be easier. The 3000w of lighting isn't relevant if it's being exhausted away. Do chuck some old duvets on the roof of the tent though, so the heat gain from the lights doesn't warm the bedroom. Aircon on the landing could mean the condenser in the roof. Swap the loft hatch for your own bit of wood. Then you can send your cord through. You could route the tents exhaust that way to. Out the bedroom to use the loft. That duct run could be useful for system balancing. Done by adjusting the amount of insulation around it, as you do the tent roof. If the aircon is sized right, max insulation. If it's too big, remove insulation. Doing so allows the tent to warm it's inlet air.

Still hard to put figures on that aircon, without air volume and temperature drop needed. I think 12000 will be massive, and cheap if you use a typical ducted mobile unit. No cords.
As I said, a 12000 will drop the air 10c easily, and quite a lot of air. Your extract will be a bit higher volume than the 12000 delivers though, so some air will be passing the 12000 without going through it. No more than half though. The fan, like the insulation, is balancing. Though RH needs will set it's speed ultimately.

 

[CertifiedRefugee]

Very few people insulate their tent. Without which, you really would struggle. Insulation board is stiff enough to be a construction material, without much need for framework. Just a floor board across the roof on the tent, dead center, would let boards rest upon it. So as to span the distance.

If properly wrapped, all heat leaves through your exhaust, and is gone. Without insulation, heat leaves through the tent wall, warming the air going into the tent, or the space around the tent. The insulation ensures the heat you create, leaves through your insulated ducting. Also, with reasonable air exchange speed, that garage can bake all it wants to. As garage heat is so slow getting through the boards into the tent, it can't do anything before the air has already been exchanged.

The mission, is supplying the tent with cool air. Feeding it from outside through insulated duct perhaps. Or you may need to treat it on along the way. A second smaller tent might be key. Also insulated, it can house hummers, de-hummers, heaters, coolers. Your lighting load that looses relevance. Your intake air temperature matters. How hot is it at night? I can run a room fine in 30c weather. About 33c in the room I used to start shutting off HID lighting, but with LED people have rocked though 38c weather, with who knows what in their rooms.

I don't recall a thread about people loosing plants to heat. Certainly some shut down, but maybe they are just not as professional. Do glass-houses in cali shut down?

ok hear me out i have a ac infinity cloud lab 811 tent and two DE 1000watt hellion ...the other 1000watts I'm referring to is for the equipment like fans,humidifier,dehumidifer,pumps etc. give or take. Apparently it doesn't look like I will be able to cool it without buying a mimi split.

 

[Ca++]

ok hear me out i have a ac infinity cloud lab 811 tent and two DE 1000watt hellion ...the other 1000watts I'm referring to is for the equipment like fans,humidifier,dehumidifer,pumps etc. give or take. Apparently it doesn't look like I will be able to cool it without buying a mimi split.

You might have to adjust your seat a little, for a different viewpoint.

I presume your tent is a typical setup. Where there will be extraction heading out the house. We can talk about that as it's own topic.

I presume your inlet air is coming from the house, or perhaps outside. Again we can split that conversation into its own paragraph

That's grow tent 101, and works.

I hear you are doing this, though correct me if I'm wrong, or I will be talking about your garage again

The reason you are expecting problems, is because the air going in to the tent is too warm.

This means that any extra extraction is no help, as it just pulls more hot air into the tent. If it's 30c air outside, it can only get hotter as that 30c passes through your tent and past the lights. What you need, is colder air going into the tent. Like it was colder weather.

Have a look over these few points, and tell me whats right and wrong. Copy and paste the lot if you want, and edit it where needed. I want to get the job clear in my mind, and just help with the bits you need help with. Not muddy the situation.

 

[Ca++]

I'm just chucking this post in here, for general reading. It's not specific to the job at hand.

The basic principle is here. The grow room is getting it's air off the stairs, so the stairs want to be cool.

There is a presumption here, that the house isn't very well sealed. Perhaps a bathroom window needs leaving open. Somehow enough air must enter the house, to cover the extract needs of both the tent and the aircon. For this reason, you may decide a two box aircon solution is more suited. Perhaps with the hot box outside, if that won't look strange.
The two box solution won't send out smell either. Sometimes you will open that tent, so the bedroom smells. You want that smelly bedroom air to creep back into the tent. Some will spill out into the stairs. With a two-box that smelly air will go back in the bedroom. With a tubed system, some will be extracted without odor filtration.

A hole into bedroom ceiling is a bit rough. Perhaps you have a chimney. Or you could take that extract duct, out the bedroom door and through the stairwell loft hatch. Fit a new hatch you don't mind cutting a hole in.

You may need the bedroom door closed. There is a garage below the floor, which could provide air. You would probably need to build a wall across the door using insulation board.

I spoke of insulating the tent, which seems to be something rarely done. Lets say the stairs here were 24c and the tent was 30c at the top. Many people are expecting the air in the bedroom to be the same 24c as the stairs. So the tent is sucking in 24c. It won't happen. That hot black thin tent will warm the bedroom. Heat you want to extract, is instead warming your intake air in the bedroom. With HIDs running, the tent can feel baking hot as you walk past. It's heat that should be going out the extract, instead warming the room. It's actually a large amount of heat lost from a warm tent to a cool room. All of which means extra capacity aircon and extract. It could be 28c over that tent. More heat escaping back to the inlet, than going out the extract. Insulating them is standard practice for me, and makes a considerable difference. I had a friend put a tent in his garage and no matter how many heaters he ran, it was just too cold in winter. Fixed it with some old bedding. It works both ways. Look at home insulation to keep a 20c difference between inside and out. It's 12" thick. Tent fabric is useless. I can't stress this enough it seems.


I'm running something like the drawing right now. I have the aircon in the purple bedroom where I am sitting. The hose is out the window. My purple room is nice and cool, and the cold air slips along the stairway floor and into my grow room. Like in the pictures, or most stairwells, my cold air would like to slip down the stairs. It's cold and heavy, so clings the ground. I have a stairgate, made of card, to stop my cold air escaping. In the pic, you would have to do the same. The cold air wants to drop to the front door, where the hot air wants to rise from. We must contain it. For me, I must make a physical barrier. For a stairwell unit, it could blow in the right direction.

Just some notes for readers..

 

[Three Berries]

LEDs convert ~90% of the electrical input to light.

Light Bulb Efficiency | Center for Nanoscale Science

www.mrsec.psu.edu

 

[Ca++]

LEDs convert ~90% of the electrical input to light.

Light Bulb Efficiency | Center for Nanoscale Science

www.mrsec.psu.edu

No, that would be near 400 lumens per watt. Our lights are not 40%