Power supply air flow question

I'm considering moving the PSU to the bottom of the case I'm building, but I'm not sure there is enough space for proper air intake.

It draws with a 140-mm fan, and there will be a gap along the bottom of the case about 1/8" high, figure a total of about 40 inches in length on this gap, for a total of about 5 square inches of inlet space.

Two questions: Will this be enough inlet space to allow proper air flow for the PSU? Assuming it IS enough space, will the narrow constriction make it sound like a wind tunnel?

I can make the gap wider if needed, but I wanted to get some input from those with more knowledge of air flow than I.

Thanks!!

What are your actual temps?
how good is your airflow now?
what are the specs of your rig?

I don't have any temps now, as the case is still under construction. Air flow to the rest of the system will be excellent, but being on the bottom the PSU will be sealed off from that air flow, drawing air all by itself out the bottom of the case and expelling it directly to the back of the case. Airflow in the rest of the case is irrelevant with the PSU in this position.

I will be using a Kingwin Mach 1 1000-watt modular PSU, specs can be found here.

Best case scenario (heh) is to have a dedicated inlet there with a filter, as you will pick up dust. However, you may find it's enough airflow, if it's not over about 60% load. More load, more heat. Conversely, more heat, less power-so don't skimp on airflow.

I personally would open it up as best I could to fresh air-if it hovers right over the floor, up by a CM or so, I'd cut a hole and seal with weatherstripping tape to kill the noise.

Ok, I checked the plans again, and the edges will actually sit 1/4" off the desk rather than an 1/8", so that's roughly ten inches of inlet space. I do plan to seal around the PSU on inlet and outlet both so its airflow will be independent of the airflow to the rest of the case. I hadn't considered a filter, but I'll definitely incorporate that into the design now, thanks!