Question Recommend good quiet fans for an electric food & beverage cooler ?

[exekutive]

I need to replace the fans in my electric food & beverage cooler. They are getting quite noisy, and it's a nuisance when sleeping on the boat. Need something that moves as much air as possible, but more importantly, they need to be whisper quiet. Supply is plain DC 12V. No motor controllers.

I figured you PC guys would know what the best case fans are. Any suggestions please?

 

[Paperdoc]

Are these fans blowing air through pretty open spaces, or are they blowing through a finned radiator? Also, what size do you need? Computer fans generally have square frames, and the size label is the length on one side of that frame. Of course, the spacing of the mounting holes in that frame also will be important to you so you can fit it into existing mounting holes.

You do NOT need the new 4-pin PWM fan type, and actually should buy the older 3-pin type for a fixed 12 VDC power supply.

 

[punkncat]

The first thing I would suggest is to take off or access the model number to the fan already in the unit and check for a replacement. A food and beverage cooler will be dealing with lots of humidity if not condensed water as well. I would not put a PC specific fan in such an environment.

 

[exekutive]

Are these fans blowing air through pretty open spaces, or are they blowing through a finned radiator?

It's a thermo-electric cooler. One small fan blows through a finned radiator on the inside, and a larger fan blows through another finned radiator on the outside. They looks just like PC fans. Square frames screwed directly to the fins.

Also, what size do you need?

I'll measure them up and post back soon.

You do NOT need the new 4-pin PWM fan type, and actually should buy the older 3-pin type for a fixed 12 VDC power supply.

That's what I figured. Although, I would consider mounting a standalone controller if I that would achieve significant efficiency or noise improvements.

Thanks for your time.

 

[exekutive]

The first thing I would suggest is to take off or access the model number to the fan already in the unit and check for a replacement. A food and beverage cooler will be dealing with lots of humidity if not condensed water as well. I would not put a PC specific fan in such an environment.

I will check, but they do not look like anything special. If the humidity results in having to replace the fans every two years, then so be it.

 

[Paperdoc]

For this you will NOT need any kind of Controller. As you describe the system, you say each fan is fed a constant 12 VDC at all times from some power supply, and there is NO means of altering the fan speeds. I presume that means each fan has TWO wires to it. On a normal computer fan, these would feed into Pins 1 (Ground or -) and 2 (+12 VDC supply). No other connections. That does not require any Controller system.

That system you have uses a Peltier type of cooling device, which can move heat at only modest rates, so the fans involved do not need to be super-high-power ones. But since they are mounted on finned heat exchangers as I expected, they should be ones designed for "pressure" applications, not "air flow". If you have specs to read, that means their pressure rating in mm of water should be well over 1, preferably close to 2 or even higher. I suggest you look through the models made by Noctua

Noctua

Noctua's premium fans are internationally renowned for their superb quietness, exceptional performance and thoroughgoing quality.

noctua.at

That's their master list, on several tabs. Do not consider their Industrial PPC line - they are very high-power units that consume more electric power, can blow at high rates you do not need, and create more noise. I suggest the Redux line. That is their older design but still very good, and slightly cheaper than newer products. (Some users are not happy with the colours of those fans, but that probably does not matter.) Click on the Redux tab, scroll down to the size group you have found, and look at details of 3-pin models. Click on one fan name in the left column to get detailed specs. A small note if you are comparing with other maker's spec sheets. Noctua specifies the fans' max air flow in m³/hr, whereas Americans always use CFM. To convert, CFM = m³/hr x 0.589.

In general comparison to other makers, Noctua fans deliver pretty high air flow for the same electrical current consumption, relatively low noise, and have long lifetime - warranty typically is 6 years, and most users say these fans do exceed that lifetime.

 

[exekutive]

A food and beverage cooler will be dealing with lots of humidity if not condensed water as well.

Believe it or not, it actually stays pretty dry inside. Remember, cold air is drier than warm air. Even if there were condensation on the inner walls of the cooler (which I haven't seen), the fan sits on top of the radiater so is pretty isolated.

Anyway guys, here they are. These fans look about as cheap and junky as they get.

 

[exekutive]

The cooler is indeed based on a Peltier element. That's why I got it: low power consumption. It works great for being in the wilderness for weeks at a time.

they should be ones designed for "pressure" applications, not "air flow".

Air flow is what conducts heats away from radiators. This is not a sealed enclosure where you need to build pressure differences.

I suggest the Redux line.

Thank you for the Noctua endorsement. But I disagree about the model. The A-series sounds exactly like what I want:

The NF-A9 is a highly optimised, premium quality quiet 92mm fan. Featuring Noctua’s AAO (Advanced Acoustic Optimisation) frame as well as sophisticated aerodynamic design measures such as Flow Acceleration Channels, the NF-A9 further improves the renowned quiet cooling performance of the award-winning NF-B9.

ALL the specs are better. airflow, pressure, accoustic noise ... and the power consumption is 36% less than the Redux. Benchmarks agree that the A series is the best for cooling PC's.


As for the smaller fan, Noctua doesn't make any 60x10 fans.

 

[Paperdoc]

"Pressure" fans are not intended for creating pressure inside a closed case. The name refers to the backpressure the fan can blow air against. The backpressure is a result of the resistance to air flow immediately in front of the fan. That is why such fans are used for blowing thought finned heatsink devices.

The actual air flow generated by any fan depends in part on how much resistance to air flow is created by any obstacles in the path of that air flow. Those obstacles could be anything. In published specs each fan has a rating for Air Flow and another for Pressure. What these two really are, are the MAX values under DIFFERENT circumstances. Air Flow is the max air flow generated at fan full speed when there is NO impedance to air flow on intake or discharge sides. But as resistance to air flow is increased, the actual flow is reduced. The amount of resistance can be expressed as the pressure difference between the inlet and output free-space areas on either side of the fan. As resistance (backpressure) increases the actual air flow is reduced until at some backpressure value the effective air flow is down to vitually zero. At any backpressure higher than this there will be effectively NO air flow at all. VERY roughly if you were to sketch a graph of air flow versus backpressure, the line is almost staight from max flow at no backpressure, to no flow at a backpressure value cited as the "Pressure Rating" of this fan. You could use this to compare two or more fans from the specs by plotting such a simple line for each on the same sheet of paper. One often finds that such lines cross, with Air Flow fans exhibiting higher flow a no backpressure, but Pressure Fans performing better at some intermediate backpressure and higher. However, if the two fans are very different, there may not be a crossing point.

 

[exekutive]

Thanks. I ordered a NF-A9 on Amazon for 22 CAD.
I'll leave the inside fan be for now. Since it's inside, the sound should be fairly well insulated. We'll see.

 

[Karadjgne]

Noctua 60mm fan

 

[exekutive]

Noctua 60mm fan

25mm deep. Won't fit.

 

[exekutive]

Well the new cooling fan is in ...

And while it is quieter, it isn't nearly as powerful as the old one. I would say the old one blows around 3x more when I put my hand in front of it.

Also, the Noctua makes an annoying buzzing noise when unobstructed. If I place an obstruction in front the the inlet then it goes away. It's audible with headphones in this video I recorded:

We'll see how it actually performs ....