mcinnc

ive been using the cold air from the centrifugal fan that my central A/C all runs off of, to cool my grow closet. I think i'm an idiot. Heres what i did: I thought, "hey, i'll block off every other air vent in my apt. except the closest one to my closet. Then, ill rig up 6'' duct from that vent, and run it directly behind my fan in my closet. this will give it max CFM and cool it better than leaving the other vents open."
So i took down all the other vents, blocked the air from coming out of them with squares of cardboard, and screwed them back up. Leaving no place for ANY cold air to go except for the one i rigged the duct up to, and ran to my closet.
For the first 2-3 weeks, this worked perfectly. i had it where my grow closet was dialed in around 76f all the time.
Then, trouble starts. my centrifugal fan starts cutting off when it should not. Then it starts blowing just SLIGHTLY cold air. not cold or warm, but a few degrees less than just "air" blowing from a fan. My theory is that i'm stressing the shit out of my central AC fan by forcing all its flow to one vent, with just 6'' of duct to blow out of. like trying to exhale as hard as you possibly can through a coffee stirrer straw. hope this makes sense.
So my question is: IS that why my AC is fucking up? if yes, what can i do to fix it? i've tried cracking some of the blocked vents in the other rooms to take less strain off of going into that one vent. didnt work. im at a loss. PLEASE give me some advice.
Oh, and feel free to call me retarded. seriously.
thank you in advance
<3 Retard #1

Underarock

if you cut the air flow on an ac unit
the coils gets too cold
the perspiration freezes on it instead of dripping down it
it turns into a block of ice

you can check it where you change the filter in an apartment
and change the filter while your at it
run it fan only till it thaws out
not cool or heat
then unblock a few vents

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mcinnc

Thank you kind sir!!

sek311

Hello my background is mechanical engineer but I also have a HVAC background (family business) so I am a licensed contractor too. So... YES you are ruining your AC! Please stop what you're doing unless you want major repair bills. I understand the need to keep your closet cool but you're going about it the wrong way.

It is true that condensation maybe freezing on your coil. But what you should be more concerned with happening is something called "flood back". See a AC works on a few thermal mechanical principles. Heat and pressure change is needed to change refrigerant into a super heated gas, this heat is collect in the evaporator coil. The superheated gas runs about 50-55 degrees which in turn goes into the compressor and COOLS it down. It is the primary cooling method and the added heat helps shed heat more efficiently in a later cycle. Remember the compressor is basically a motor driven pump that generates HEAT. Now in the absence of heat in the evap (which helps change liquid refrigerant to a gas) a good amount of the refrigerant remains a liquid and "floods back" to the compressor effectively washing the motor and pump bearings of oil. So when you flood back think about it like running your truck without your 10-30w in it and then driving to Vegas. Flood back also causes mechanical damage on valve or vane compressors. Bad news if there is damage you're screwed, loss of efficiency and loss of lifespan. Good news if your AC is newer there were safety sensors installed for people who forget to change their filter every 60 days of use.

Now here is a example, heat carrying air flow is required for proper heat exchange 12000btu/400cfm and a common central system is 3 ton for a small home. You're not getting anywhere close to 1200cfm out of a single room register.

So here is my advice, you're basically running your AC units fan coil in a almost static condition meaning hardly any air pressure change or movement. But you can by design run a system with SOME vents closed to save energy and increase CFM in a needed area so do that. Then hijack your cooling from a conditioned room which is part of a static system and not destroy your AC system that will cost painful amounts of money to repair and replace. Not to mention the intrusion of privacy from a repairman. So to wrap it up make your room 72 degrees and then push and pull that cool air into the closet. OR buy a portable AC. If you any questions or advice let me know. You aren't a retard live and learn my friend.

kingseven

Yep, you are choking it out!

sek311

btw way if your AC doesn't come back online you could have popped a fuse by the condenser if you have a multimeter i can talk you through diagnosing it.

Them

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