Darr247
New Member
- Joined
- Sep 12, 2012
The top-mounted 380W power supply in my sister's HP Pavilion died, so I bought a Cooler Master 500 (RS-500-PCAR-A3) on sale ($35) at newegg to replace it. I see I could have gotten it for a net $30 if I wanted to wait 10-12 weeks for the $10 rebate that started today.
The stock supply had a 70mm (or 80mm, depending how you measure... blade tip to tip is 70mm) fan drawing air through it and exhausting out the back.
The Cooler Master has a 110mm (the box says 120mm, but I measure 110mm edge to edge on the blade, and the opening the blade sits in is only 112mm, so I don't know how they can call it 120mm) blowing IN to the power supply, which still exhausts out the back.
So, I went through a few threads here seeking a definitive answer to this question, but they all dealt with bottom-mounted supplies.
The mounting plate on the back of the case has extra screw holes placed so it can be mounted fan up or fan down.
Should I mount the fan towards the motherboard or towards the top of the case?
There is no vent on top of the case, and I'm not going to take the dremel to it to make any (it's not MINE). There is about 15mm (19/32'') of clearance between the power supply and the top of the case. It's open on the 'front' edge and the side with the removable cover... except for a 10mm gap near the back corner, it sits tight against the backplane on the other 'side' and tight against the back, of course.
So, 15mm x (140mm+150mm+10mm) gives 45 cm² (about 6.975 square inches) of opening if I mount the fan facing the top.
I figure that should allow a flow up to 40 cubic feet per minute (@5.8CFM per square inch of opening, though I see Panaflo fans are rated at 7.9CFM per square inch; it's NOT a Panaflo fan), but I don't find any specs for what the minimum CFM should be through the power supply.
e.g. Manual
Spec Sheet
The maximum the 112mm opening should flow is ~88 CFM using that same formula. i.e. 3.14159 (2.2'' x 2.2'') 5.8 CFM/in² = 88.2 CFM
However, with the IEC socket and the on/off switch, plus the grill blockage, the openings on the back are smaller, and that opening should max out about 65CFM.
The stock supply had a 70mm (or 80mm, depending how you measure... blade tip to tip is 70mm) fan drawing air through it and exhausting out the back.
The Cooler Master has a 110mm (the box says 120mm, but I measure 110mm edge to edge on the blade, and the opening the blade sits in is only 112mm, so I don't know how they can call it 120mm) blowing IN to the power supply, which still exhausts out the back.
So, I went through a few threads here seeking a definitive answer to this question, but they all dealt with bottom-mounted supplies.
The mounting plate on the back of the case has extra screw holes placed so it can be mounted fan up or fan down.
Should I mount the fan towards the motherboard or towards the top of the case?
There is no vent on top of the case, and I'm not going to take the dremel to it to make any (it's not MINE). There is about 15mm (19/32'') of clearance between the power supply and the top of the case. It's open on the 'front' edge and the side with the removable cover... except for a 10mm gap near the back corner, it sits tight against the backplane on the other 'side' and tight against the back, of course.
So, 15mm x (140mm+150mm+10mm) gives 45 cm² (about 6.975 square inches) of opening if I mount the fan facing the top.
I figure that should allow a flow up to 40 cubic feet per minute (@5.8CFM per square inch of opening, though I see Panaflo fans are rated at 7.9CFM per square inch; it's NOT a Panaflo fan), but I don't find any specs for what the minimum CFM should be through the power supply.
e.g. Manual
Spec Sheet
The maximum the 112mm opening should flow is ~88 CFM using that same formula. i.e. 3.14159 (2.2'' x 2.2'') 5.8 CFM/in² = 88.2 CFM
However, with the IEC socket and the on/off switch, plus the grill blockage, the openings on the back are smaller, and that opening should max out about 65CFM.