Question corsair 275Q fan set up

[julesbluemonday69]

So, I have a corsair 275Q case but I have a question about setting up the fans. Right now the only exhaust is the 120 mm fan in the back. I have three intake fans in the front. There is a spot for a 140/120 mm on the top close to the front of the case followed by another spot for a 120 mm. I am not going to use a water cooler. I want to add fans to the top two slots. The case does come with a cover for the top of case with some tiny magnets that lets no air in or out. The magnets have already come off and I modified with super glue and got similar stronger magnets from home depot and glued it so the cover sits higher(may add more so it sits even higher). Question is should I use a 140 mm on the top of case or go with a weaker 120 for the exhaust? If I put a 140 mm fan, would it not suck out the intake air from the three front fans? Also all the components that need to be cooled are towards the back of the case obviously. Right now just for the time being I have 140 mm fan on top near the front of case blowing air into case in front of the mobo. Excuse my ignorance as this is my first build but I'm sure the top fans should be exhaust fans. I know there are better cases for airflow but I'm not into the whole glowing lights everywhere trend. Thanks in advance for any advice and suggestions.

 

[julesbluemonday69]

Okay, so i removed the 140 mm fan and installed a 120 mm as an exhaust, I need to install another exhaust fan towards back of case but I need a slim fan as noctua cpu cooler is too big..... Hoping a slim noctua fan can fit, stress testing cpu using cpuid reaches about 50 c. So I think im okay for now, did not run test for too long. So just need to modify upper top cover and hope slim fan can fit above cpu cooler in case, at idle i'm at 21 c.