Dahua NVR Quiet Silent Fan Mod

Replying to myself... because I couldn't resist, I plugged 14 fans into a spreadsheet and calculated CFM per dBA. They were all in a pretty tight range of 2.55 to 2.86 dBA/CFM. So there is a fairly direct relationship between noise and cooling ability. Basically, to move 10 CFM of air, you are going to get 26 to 29 dBA of noise - not a huge range.

Every 10 dBA increase is a 10-fold increase in sound intensity (perceived as roughly doubling of loudness). So we can shop for something at the lower end of the range, but the only significant decreases in sound are going to come with a similar significant decrease in cooling ability. Dahua didn't just install a cheap, loud fan - I'm guessing that their sole priority was cooling ability (safety/longevity) and not loudness.
 
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You’re right. As the saying goes “there is no free lunch”. To move an adequate amount of air with a 40mm fan, you’ve got to spin it fast. Fast means noise. No matter how the fan is designed.
 
PJPJPJPJ said:
I have a Dahua 8 camera Power-Over-Ethernet NVR (NVR 4208-8P-4K-S2). I suffered from the same fan noise issue here as everyone else. To echo the comments and provide some clarifications and precautions, at least on this NVR unit.
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@PJPJPJPJ , thank you! I have the NVR5208-8P-4KS2E and the same noise problem. I'm finding solutions, your detailed post was perfect. I'll buy the new fans and cutting away that fence. I will post the photos.
 
Hi Guys,

I just boughta DAHUA 5216 and didn't realize that the fan was so louuddd. I have a DAHUA NVR 8 POE with external power supply and I was wondering if I could make a mod to plug this external power supply so I don't the to cool the internal one. Does someone already tried that?
 
Just as an update to this OLD post. Please see my mod earlier in this discussion.

My unit is in my garage. It has been working without incident since installation. No overheating, no issues.

I'm posting this because outside temperatures have been 95-100 degrees, and my garage has been around the 100 degree mark. Security system keeps plugging along flawlessly with the much quieter fan, additional ventilations holes, etc.
 
J Sigmo said:
I just thought I'd add a few comments.

First, I love getting computers and other gadgets as quiet as possible. We become accustomed to a lot of ambient racket from PCs and the like, and it's a blessed relief when we can get them all to be as quiet as possible.

Next, it's always best to keep our electronics as cool as possible. That doesn't mean we need howling fans, but good airflow is essential. So tradeoffs need to be made, for sure.

Larger slower-turning fans are always quieter than smaller high-RPM fans that move the same amount of air. So if possible, open things up and use slower, larger fans to do the same job.

Look at how old-school sirens are made. The concept is usually a spinning disk rotating very near a stationary disk, with holes drilled in both disks. Now think about a typical fan setup. Often, a fan is mounted very close to a cut-out in a case, or a "finger guard" that is stationary. That makes a siren! So mounting the fan farther away from the stationary grill or cut-out in a case can quiet things a LOT. You want to avoid building a siren when you design a fan system. It doesn't take too much space between the rotating blades and the stationary grill to quiet a fan system substantially! Just installing some spacers between a fan and the case can help a lot. But you then also need a shroud or other way to seal up the "connection" between the fan and the opening in the case so air won't "short circuit" inside of the case. You want to pull in ambient outside air, after all.

Keep your electronics cool with a lot of air flow. Don't starve your devices for air flow for the sake of quiet. But design your air-moving equipment carefully to get good air flow without making a lot of racket. For most semiconductors (and a lot of capacitors), their life is cut in half for every 10°C of increased temperature. Cool is good! But quiet is also good.
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On my Dahua 5216-16P-4k2 I used small metal snips to cut out the metal mesh over the power supply fan in the back, without removing the cover or anything else. It took the siren noise away..now just loud air flow. Don't have cats or kids in the house
 
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Fellouss said:
Hi Guys,

I just boughta DAHUA 5216 and didn't realize that the fan was so louuddd. I have a DAHUA NVR 8 POE with external power supply and I was wondering if I could make a mod to plug this external power supply so I don't the to cool the internal one. Does someone already tried that?
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Try cutting the mesh off with small metal wire cutters and bending back the tips around the edge.
 
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I have a Dahua NVR 4116HS=4KS2 (without built in POE). I didn't like the fact that it had only one fan, and that factory fan was pulling cold air in, which did not seem that effective. I went with two Noctura 40x10s and am very satisfied with them. the noise level is the same as the oem fan, but now I have two fans, pulling and pushing much more in and out of the unit. I do not like passive cooling at all. I do agree one of the biggest killers of electronics is heat. I did cut the mesh off of the sides and the noise, although still there, it isn't that loud. It is in our TV room, and honestly, during the day, you can barely hear it. Earlier in the morning and late night, yes, but just a little hum.
 
Bought the Noctura fan and installed. Upside down but I don't think it matters. It's so quiet I had to see if it was spinning. Had to cut more of the cable off (2 ") and not use the universal connector. I couldn't get all the wire length stuffed in.
 

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Bryan said:
Bought the Noctura fan and installed. Upside down but I don't think it matters. It's so quiet I had to see if it was spinning. Had to cut more of the cable off (2 ") and not use the universal connector. I couldn't get all the wire length stuffed in.
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Nice! Did you installed the pin reducer cable also?


Sent from my ONEPLUS A5000 using Tapatalk
 
Did some of you changed also the fan case (size 40x10)?

Sent from my ONEPLUS A5000 using Tapatalk
 
PJPJPJPJ said:
Comparing the Sunon MagLev HA40101V4-D26C-999 and the Noctua NF-A4x20 FLX...
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I was confused about this but I think you meant to compare the "EFB0412HHD" to the Noctua.

I know its an old thread but it showed up in search when I was looking up the Sunon part number so I wanted to add details for anyone considering replacing the Sunon 40x40x10 fan that finds this post going forward.

When I looked up the specs on the HA40101V4-D26C-999 the closest I could find is the HA40101V4-000U-999 which I believe is the same thing with a different country code.
The specs show it as 40x40x10mm, 12VDC, 5.3CFM or 9.00m3/h, 0.8W, 18.2dBA, 4500RPM 0.06inch H2O Mouser Link: HA40101V4-000U-999
The newer version of this (HA40101V4-1000U-A99) specs a little better but I as you stated these are almost silent and changing this wouldn't really gain you anything... 5.4CFM or 9.17m3/h, 0.38W, 15.7dBA, 5000RPM, 0.09inch H2O Mouser Link: HA40101V4-1000U-A99
 
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