Ashmore11

Grow room is still hitting 90-100 (mainly 100!!)

Have a look at the pics below and see if you can see any flaws?
Im really trying my hardest to get this temp right and have spent so much money now ($955)
I am starting to really stress out so please help if you can

Fortunately the plants are still looking healthy! but for how long!!!!!!

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EMj

How big is the inline fan? General rule of thumb is half the CFM as watts.

Could you outline the equipment you have? That would help.

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burndt

Need more info.

What size lights, what is the CFM rating on your fan, what size is your grow room, how long of duct runs do you have?

Normally, it's a good idea to pull through your scrubber. Why do you have a split 45 on your line?



USED AS EXAMPLE
1.) Convert all inches into feet
Quote:
inches ÷ 12 = feet
38÷12=3.16'ft W (rounded up to 3.2)
28÷12=2.3'ft D (rounded up to 2.4)
42÷12=3.5'ft H
2.) Find the volume, feet cubed, of your cab.
Quote:
multiply Width × Depth × Height
W × D × H = feet cubed
3.2'ftW × 2.4'ftD × 3.5'ftH = 26.88'ft3
3.) Find for Exchange CFM rate. We want to echange the volume of the cab 4 to 5 times a minute. I will use the value of 5.
Quote:
feet cubed × 5 = Exchange CFM
26.88'ft3 × 5 = 134.4CFM
4.) Find for Additional Electrical Cooling CFM rate. Add all the watts of all equipment inside the cab.
Quote:
total watts of all equipment ÷ 4 = Additional Electrical Cooling CFM
250 watt light + 50 watt additional equipment = 300 Total Watts
300 Total Watts ÷ 4 = 75 AEC CFM
5.) Add the two CFM rates to get Total CFM
Quote:
Exchange CFM + AEC CFM = Total CFM
134.4 Exchnage CFM + 75 AEC CFM = 209.4 CFM
6.) Find the CFH (Cubic Feet per Hour) from the Total CFM rate.
Quote:
Total CFM × 60 = CFH
209.4 Total CFM × 60 = 12564 CFH

7.) Find for the amount of carbon needed for the filter.
Quote:
CFH × grams per foot of activated carbon (0.36) = total amount of carbon required.
12564 CFH × 0.36g per ft = 4523.04g
8.) Divide the amount (in grams) of total carbon by the length to yield the radius quotient. This is done with 2.6cm thickness as a constant.

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Luke Highwalker

could you walk me through what the hell is going on in there?

i see alot of T's and Y's..those thing hurt flow like no other.

also looks like a 4" can filter...i cant figure out how you have the air flowing...

lay out a little more what you got going on, what kind of equipment, how many watts of light etc.

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Ashmore11

Ok ill do my best!

• 2 x 600 watt HPS bulb & ballast
• 1 x 125 cfm inline fan & filter
• 1 x 200 cfm inline fan
• 2 x Air Conditioning Units
• Room Size: 8' x 4' x 7' / 32 sq/ft

I am using both Inline fans as an exhaust! the temp outside my room is 90f+ and seems kinda dirty so i have no intake. I'm starting to think i might have to buy cool tubes!!!

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Luke Highwalker

so let me get this right.

you got 2 600w lights with standard reflectors.

both a/c units have an exhaust duct hooked to the black T, that T is then cut through the wall. correct?

then there is a Y connector with a fan on either side, and one side has the 125cfm fan and filter, the other side just a 200cfm fan.

neither of the fans are hooked to the duct coming out the back of the a/c units are they?

looks to me like a simple case of too much ventilation. either one of those a/c's should be enough to keep the room cool... i have a single 6500btu a/c that keeps my closet at 79, no sweat.

the fans inside those a/c units are not very strong... those are the unsafe kind to run in a grow, because they pull dirty air out of the room, across the coil and out the back of the unit. this is how the a/c cool themselves. like i say a/c dont make cold..they just relocate the heat.

with your 200cfm and 125cfm fans sucking out the box, with no intake vent. well, the cab is going to get air from somewhere...and that will be the path of least resistance.

i think your exhaust fans are either sucking all the a/c out of the room, or they are making the neg pressure in teh room so high, that all the hot air that is supposed to be going OUT of the a/c is actually being sucked through the a/c the wrong way and the heat is being pulled into the room.

first, i would take the Y adapter off, toss one fan to the side. Hook up one fan and one filter pulling air out the top of the box. make the inlet right above the light reflectors to maximize cooling of the lights.

now cut a small intake vent in teh cab, somewhere near the floor. AND NOT ON THE SIDE WITH ALL THE HOT SHIT!

either keep your a/c's plumbed the way they are, or relocate them to the other side of the wall, and build a duct to blow the cold air into the room, instead of having the entire ac unit in the room and trying to blow the hot air out {you are exhausting stinky air the way you are now, moving the a/c and ducting the cold side will prevent this odor loss} by doing this you are basically converting your standard upright unit into a kwik cool unit from cap. take a look at theres and you will see what i mean.

so either choose a/c or active ventilation....you cant do both, successfully.

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HOTBOX: Cheap & Easy in room A/C

Ashmore11

no, fans and a/c have separate ducts.
Ok so from what you have told me i have thought of this:
Switch the 125 cfm with the 200 and discard the 125 (can i just block off 1 of the holes on the Y?)
Switch off 1 a/c and see how that goes?

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Luke Highwalker

i would remove the Y altogether, if you could. the fan blowing through the carbon filter really shouldnt matter to much...

for testing purposes you could just turn off one of the fans, and plug the hole the on the end.

the T between the ac's need to go too. you are likely blowing hot air from one a/c through and out the other. they really need to have there own ducts with there own holes in the wall. a 90 degree intersection does not flow air worth a damn.... the 2to1 merge of the y would be much better for joining two blowers to a single outlet but still should be avoided... remeber the a/c probably dont cycle in unison, so while ones off the other is blowing hot air back into the room.

if it were my grow room i would, in this order:
Unplug which ever a/c works the worst.
Remove the black T entirely.
Hook ONE a/c vent to the exhaust hole in the wall.
turn off ALL ventilation for your box. except for the a/c

the a/c alone should be enough to keep the room temp stable. it will take several hours for it to level out, esp if the lights are on.

now switch on the fan and filter...just one. keep in mind that you need a passive intake into your box if you have a fan pulling out. if the doors and what not dont seal then that should be enough, otherwise drill a hole through whichever wall has coolest air on the other side.


lastly, the room the a/c vents its hot air into....that room needs some sort of ventilation of its own if it is not otherwise climate controlled

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HOTBOX: Cheap & Easy in room A/C

Ashmore11

on the a/c there is an option to have cooling all the time and also one that switches between 2 phases. Im sure these options are on every a/c so which option is the best to have my a/c on? I noticed you said the a/c's dont switch on in unison. Is that cause you use the 2 option setting? Bit confusing i know!

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Luke Highwalker

a/c's dont cycle in unison for many reasons.

first, the set point. sure the display says 70 degrees, but really the thermostat allows a swing of typically 3-7 degrees. so you are either usually a degree to 3 degrees over your set point before the a/c will cycle on and start to cool.

secondly, is plain old fashioned tolerances. most temp senders have a accuracy of 2 degrees, so couple that with the differential temp and you have a fairly wide range of temp the a/c has to maintain. the sensors will heat up and cool down at there own rate, causing the ac to cycle basically when it feels like it.

lastly...a/c's operate off pressure. basically there are 2 radiators and a pump inside the unit. one radiator is located inside the room {cool side} the other is located outside teh room or in a special hot box {hot side of ac}

the radiator that keeps the room cool is connected to the pump on one side, and the other radiator on the other side. however in between the two radiators is a restrictor, called the orifice tube.

the pump keeps the pressure inside the radiator high, as this pressurized gas leaks out of the radiator it freezes it. exactly the same reason why a fire extinguisher gets cold as you use it, or any can of compressed gas freezes if you just dump it.

The last part of the puzzle is the cyclic switch. this is located between the cooling radiator and the orifice tube. it senses the pressure, as the refrigerant leaks out of the tube the pressure in the system drops. once it is low enough the compressor kicks on and repressurizes the system. the goal of the a/c is to maintain the ideal operating pressure within the system....

so its pretty obvious teh machines will have different leak down rates based on many variables..size of the condensors, amount of pressure in the system, tempurate of the air coming across the "radiators" etc.

apples to apples all these variables will not remain the same in both machines therefore they will NEVER cycle in unison, even if connected to the same thermostat.

No ac pump can run 100%, they must cycle off a percentage of teh time or they will burn up. so even on max cool and an overheated room, the a/c will turn the pump off about 40% of the time regardless, because it must do so or risk freezing up.

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HOTBOX: Cheap & Easy in room A/C