Exhausting a 12,500BTU a/c

So i just installed a 12,500 btu window style A/C. I put a rubbermaid tub around the sleeve and taped it and have it exhausting with a 435 CFM 6"inline outside. I first ran it without the hole in the top and the condenser would kick off after about 10min and it was getting really hot. After i cut the extra hole in the top it will run for about 1 to 2 hours then i can hear the condenser kick off for about 10min and it will blow warm air into the room. Do i need to get a bigger inline? or maybe install 8inch ducting with a reducer? Or is this normal for them to kick off and then back on? I need to solve this problem asap the summers here can reach 120F. The ducting run is about 15 feet total in length also.

Normally they will kick off when you have reached to the set temperature in your room. Also, looks like you have a thermostat probe on your a/c vent. You need to put that on your plant canopy. That is where the temperature needs to be measured.

I have a few hygrometers around the canopy i just wanted to know the min/max temp the ac unit puts out. I had the A/C set for 64F and it never reached that in the room lowest it would get was 74F. I dont even have my 1000w HID on yet and the room is still not cooling well enough with just a 4bulb t5 running. This A/C should cool a 9x8x10 room no prob. I dont know if a 6" 435 CFM fan is enough to vent the back of the A/C the ducting is pretty hot like 90F.

That cover on the back and the fan sucking air through the heat exchanger is probably creating negative pressure inside of the a/c. You should just try and run it without the tray or fan hooked up to the back of it and see if she runs more efficient.

I'm triyng not to exhaust the A/C's heat into my garage. Was hoping this could be done, maybe i need a bigger/smaller inline fan? Or maybe a wood box would be better. I'm sure someone has done something like this with good results.

You will burn the unit out if you do not leave the back open. Put it in a window or something, it need air flow. They make room A/C units meant for inside.

my portable unit was doing the same thing (compressor kicking on and off not cooling well) come to find out it was the filters on the unit where clogged pretty bad and heating the compressor up by not letting the fans run as efficient inside the unit. not sure if thats your problem but might be worth a min to check out. i see your theory and in my eyes i dont see why it wouldnt work, i have actually thought about doing the same thing in the past but just sprung for a portable unit instead. how hot is the air in the garage? you may need a larger fan, maybe the one you have is not keeping up with the one pushing hot air from the unit but idk.

What's up pyscho420. An Airconditioner needs to expel all of the warmness that it expels from its behind parts. That is why window style AC units have the warm exhaust air expelling into the atmosphere outside of your house. You picked a tough project to dive into so good luck fixing that problem. Other than this, I see no other problems.

It's a brand new unit the filter is sparkling and i got it for free. It seems to be "wearing in" i ran it for 4 hours today and got the room to 68F. My garage is about 80F i can imagine in the summer that will go up to 90-100F. Im in the works of getting a portable swamp cooler to cool the garage down alittle alsohttp://besthometool.com/mastercool-portable-swamp-cooler/ for free.