Antec 300 Modding

side fans are nothing but marketing and raise temps...

^ erm.. that's not strictly true though is it..

I added two 140mm fans to my Cosmos S case. I couldn't use the stock 230mm as it was too wide and touched my CPU cooler, so I made a custom window and added two 140mm fans to it. GPU (SLI) temps dropped by 9C and my CPU dropped by 6C. Motherboard dropped by 5C.

If you have a PSU at the bottom of your case, side fans can also help move the hot air that comes off the PSU, meaning your GPU's aren't sucking in that too..

Don't want to get into an argument, but it's pretty obvious that if done CORRECTLY side fans will drop your temps by a good chunk.

Anyway... back to the OP.

As you already have a fan on the side, I would suggest instead trying to add another to the top of the case as this is where hot air collects. If you have some good CFM fans on the front of the case (at least two) and then two large CFM fans on the top - you'll have great airflow.

Cutting a hole in a case is never easy.. and you have a few options. The best way to do it would be with a 100mm or 120mm holesaw. The 100mm is for 120mm fans, and 120mm for 140mm fans (the hole has to be smaller so you have somewhere to mount the fan screws).

Other options include using a dremel to cut out a new hole, but this is hard work and normally gives a poor edge when trying to cut out a circle.

If you're not looking to cut your case up, I would suggest just getting some 1900RPM, 110CFM fans (scythe for example) and just swap out your current fans for some high quality ones.. it does make a difference.

AFAIK, the Antec 300 has 2 120mm fronts, 1 120mm rear, and 1 140mm top fan?

Isn't that optimal, considering all fans are of high quality, a smooth flow of air coming in the front then out the back & top?

Side fans IMHO just disrupt flow...

I have an Antec 300 Case at work, and I'm wondering if covering up the empty side-fan hole would improve airflow...

IMHO, if you want more fans than the Antec300 provides, you should have bought a different case!!

^ I do agree that if you wanted a case with insane airflow you should have just got a different case.. but that doens't help him now. gostumpy - why not test it out? blu-tac a bit of paper or card over the hole and record temps.. then install a small 80mm fan (or whatever the A300 takes) and then look at your temps again.

OP: I would just suggest spending some good money on good quality fans and that'll be fine. I spend £70 on the fans in my case (all be it there are lots of them) where I could have spend £30. I spent the extra money to ensure they are quiet, move a lot of air and wouldn't start making a noise a year down the line.