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Calculating The Size of a Air Conditioner

R

RedRain

ya if you want to cool your home thats a good tool

to cool your grow you simply use this formula

for every 3000w you need 1 ton of cooling power.
 

krunchbubble

Dear Haters, I Have So Much More For You To Be Mad
Veteran
im going to prove there is no way to properly figure out how big of an ac it takes to cool your grow......

my 20k warehouse is cooled with a 4 ton ac, no air cooling the lights, warehouse never gets above 75.......
 
R

RedRain

im going to prove there is no way to properly figure out how big of an ac it takes to cool your grow......

my 20k warehouse is cooled with a 4 ton ac, no air cooling the lights, warehouse never gets above 75.......

ya u have a warehouse there is your answer

how many sq/ft is it in total where you are growing?

when you have a heat load on a room, such as wattage, there is a formula to calculate BTU's

how do u think they cool kitchens or server rooms?

just because u have a big open area to cool in doesnt mean you re-invented the wheel for cooling

general rule of thumb is 3 k for every 1 ton of cooling, thats with the ballasts in the room...ask any AC technician and the will tell u the same

id like to see u stuff 20 k into a basement sealed room and cool it with a 4 ton ac with no air cooling of your lights, no ins or outs.....fans are allowed in the room......
 

krunchbubble

Dear Haters, I Have So Much More For You To Be Mad
Veteran
ya u have a warehouse there is your answer

how many sq/ft is it in total where you are growing?

when you have a heat load on a room, such as wattage, there is a formula to calculate BTU's

how do u think they cool kitchens or server rooms?

just because u have a big open area to cool in doesnt mean you re-invented the wheel for cooling

general rule of thumb is 3 k for every 1 ton of cooling, thats with the ballasts in the room...ask any AC technician and the will tell u the same

id like to see u stuff 20 k into a basement sealed room and cool it with a 4 ton ac with no air cooling of your lights, no ins or outs.....fans are allowed in the room......

didn't say i reinvented the wheel......

another case in point, in my double vert, closed system room i ran 6k with a 12k portable air conditioner and was yielding over a gram a watt
https://www.icmag.com/ic/showthread.php?t=141353.....

im saying that there is no general rule to go by, to many variables.....
 
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R

RedRain

didn't say i reinvented the wheel......

another case in point, in my double vert, closed system room i ran 6k with a 12k portable air conditioner and was yielding over a gram a watt
https://www.icmag.com/ic/showthread.php?t=141353.....

im saying that there is no general rule to go by, to many variables.....

when you convert watts to a BTU load it works out to 1 ton for every 3 k

no shit there are too many variables,,especially when you are air cooling your bulbs like i stated a few posts ago....length of ducting, bends, size of blowers, etc etc........but generally speaking my formula is a good starting point,,its what any company that sells acs for growing will tell ya,,,geeze even ask excel air

my ac is only on when i turn the lights off, right now, its cold enough outside to keep my room cool, under 80.
thats what u said in post #89 so what are u doing? I smell bull shit!

not to mention if you are using a portable ac you arent running a sealed room. sealed is using a mini split, or a full ac system, no air being sucked outside,,only copper pipe carrying refrigerant. LOL

i don't know how they classified "sealed" in cali, but in BC sealed means SEALED..no ac vent hose spewing hot air outside. you need to look up the definition of "sealed".
 

greenduck

Member
i heard that it's better to have the a/c on almost all the time (when the lights are on and when needed to keep temp down to desired point) because this consistency will lead to less issues like powder mold. anyone?
 
R

RedRain

i heard that it's better to have the a/c on almost all the time (when the lights are on and when needed to keep temp down to desired point) because this consistency will lead to less issues like powder mold. anyone?

its easier on the compressor to keep running,,,

it takes the most power and effort to start, ideally you would like your AC to be running constantly
 

SMOKE-ONE

Member
its easier on the compressor to keep running,,,

it takes the most power and effort to start, ideally you would like your AC to be running constantly
So you are saying that an ac will use less power if its on constantly while the lights are on than to cut on and off?Im not doubting you.I'm just surprised if that is true.That makes me reconsider which mini split I will purchase.I planned on buying a larger one than I needed so that I wouldnt have to upgrade the ac if I added lights.But my main concern is to control the temp of my growroom,and use as less eletricity as possible while doing it.So it sounds like I need to get a mini split that is'nt too large,so that it can run constantly.Do I got that right?I can always get a larger one if I choose to add lights.Also do mini splits cut down on humidity like most ac's?
 
R

RedRain

So you are saying that an ac will use less power if its on constantly while the lights are on than to cut on and off?Im not doubting you.I'm just surprised if that is true.That makes me reconsider which mini split I will purchase.I planned on buying a larger one than I needed so that I wouldnt have to upgrade the ac if I added lights.But my main concern is to control the temp of my growroom,and use as less eletricity as possible while doing it.So it sounds like I need to get a mini split that is'nt too large,so that it can run constantly.Do I got that right?I can always get a larger one if I choose to add lights.Also do mini splits cut down on humidity like most ac's?

startup amps will always be higher, it takes more energy to start a compressor.

any AC will remove humidity as long as u are sucking the warm, hot air into the AC. its an air conditioner, it conditions the air.

a mini split with inverter technology will run almost constantly, depending on the load of the room.
 

SMOKE-ONE

Member
a mini split with inverter technology will run almost constantly, depending on the load of the room.
Even if its a little over-sized?

Also with a mini split,is'nt part of the unit,stationed outside.and if so would'nt it be suspious for it to be running during cool/cold weather?

And I know the inverter technology will assist it in running during cold weather,but is it also necessary to use a ac/heat pump combo in order to run effciently during cool/cold days?And how difficult is it to set up a combo?
I'm planning on getting a mini split asap and want to make sure I purchase the right one for my room.
 
R

RedRain

"The inverter tag found on some air conditioners signifies the ability of the unit to continuously regulate its thermal transfer flow by altering the speed of the compressor in response to cooling demand." straight from wiki

the mini split adjusts the cooling capcity of the unit by the demand on the system and never turns off, essentially maintaining a constant temp.

a mini slit heatpump will be able to be in cooling mode in colder days...check the max working temps in cooling mode before u purchase a unit.

a mini split is fairly quiet
 

aribo

New member
Impressed - covered a complicated subject very well, and easy to understand.
I have a portable A/C outside the G/room, exhaust ducted directly outside (no 'smelly' problems) cooled outlet close to the passive intake of the g/room. You can actuate the A/C with a 'room stat' placed inside the g/room - This is easy to connect SAFELY, and if you do not know what I am talking about, get someone who does, to do it for you. Even the cheapest of R/stats are accurate to within +/- 1 deg C. I also use a 1kw fan heater (which you can also wire up to a R/stat) - Fan heater stats are notoriously inaccurate. I suggest the use of two separate r/stats (1 for a/c and t'other for heater), set 3 degrees apart to allow the +1/-1 degree C inaccuracy. Hope this helps and if anyone has already posted this - Sorry, I don't intend to teach my Grand-mother how to suck eggs. :)
 

DesertPuppy

New member
Need help

Need help

"The inverter tag found on some air conditioners signifies the ability of the unit to continuously regulate its thermal transfer flow by altering the speed of the compressor in response to cooling demand." straight from wiki

the mini split adjusts the cooling capcity of the unit by the demand on the system and never turns off, essentially maintaining a constant temp.

a mini slit heatpump will be able to be in cooling mode in colder days...check the max working temps in cooling mode before u purchase a unit.

a mini split is fairly quiet

Great info RedRain (this is my first post so I hope I don't *&#% up or something).

I would really appreciate yours or anyone elses advice/tips/whatever regarding the A/C for a grow room(s) that I'm going to build just as soon as I feel somewhat comfortable about how to do it.

It will be a 10x20 room in a garage "in the desert", so the temp outside the room (inside garage) could be >120 deg (any advice on insulation?). Anyway, I'm currently planning on splitting the room into two (sealed) rooms - one 10 X 12 (flowering with 6 x 1,000W) and the other 10 X 8 (veging with 1 X 600W + equip), both separated by a light tight door. I estimate 2.5 ton split A/C but maybe need 3 to 3.5 ton with outside temps? Also, any suggestions on which A/C system(s) to get. I want to do it right (such as "ability of the unit to continuously regulate its thermal transfer flow by altering the speed of the compressor in response to cooling demand") without throwing money away of course.

Thanks!
 

KUSH&OJ

New member
I'm planning on adding a A/C unit into my room. I'm gonna be increasing from 2k to 4k and since it's summer I'm definitely going to need a A/C unit. First off I don't know much about A/C units and how to work it into a room, I'm a beginner. I have 2 options, a portable A/C unit or a Window mounted united that I can use. Issue is my OP is in a shed so I'm nervous to put a window mounted unit because of the smell leaking outside. I'm also not sure about using the portable A/C unit because I don't know where I would duct out the heat.

Anyone have suggestions or how I could do this? I would much rather use the portable just because it seems a lot easier to just set up in the room, I just need to know if anyone has an ideas about how I should feed all the hot air blowing from the unit out without smelling.

The shed is separated by 3 rooms, 1 is currently open until I set up that room for future use.

Thanks in advance for the help!
 

Yes4Prop215

Active member
Veteran
whats dimensions on that room, for 4kw sounds like maybe 10x10? im in similar situation...but i'm going mini split...portables and windows are only work for smaller grows...

im not sure what size mini split or what brand im gonna run though....

thinking about going with excel air 2 ton XL......what do yall think? at 5k for the stealth and 3k for the XL maybe theres a cheaper alternative...but id rather buy a nice AC than a stupid diamond blinged watch so....
http://www.excelair.ca/2tonpackage.html
xlseries.jpg
 
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Has anyone found they got away with using a somewhat less poweerrful air-condition than this formula indicates?
I have, but maybe it's because light-cooling fan is extra big? They run pretty cool. Or maybe I'm just lucky.
 

greenduck

Member
my setup????

3kwatts = 12,000 btu
equipment = 1200 btu
room size, 8x7x12 = 672 btu's over estimated to 1000 btu's to play it safe

12000+1000+1200 = 1420 btu's.

there are 15000btu window a/c's but im probably going to get the 18000 btu's so that the a/c's not on all the time (hopefully just 80% of the 12hrs of light) and hopefully just a few hours each night.
 

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