Fanless & noiseless UPS with maximum protection?

halcyon · Post by **halcyon** » Fri May 30, 2003 12:07 am

I know this is a PSU forum, but this being power related:

What kind of fanless / quiet Uninterruptable Power Supplies do people know of?

I tried one of the best with a fan (Powerware 9xxx series), but it was so incredibly noisy that I wouldn't even put it inside my closet :)

So, I'm looking for maximum amount of mains filtration (not necessarily so much back up battery as filtering capabilities) with a device that has no fans and makes no transformer hum/noise.

Does such a beast even exist?

regards,
Halcyon

PS I know of a few made for hifi purposes, like the Isotek Qube products, but they are incredibly expensive for PC use, imho.

http://www.isotektechnologies.com/index.htm

mudboy · Post by **mudboy** » Fri May 30, 2003 3:28 am

Uhh...none of my APC UPS's have fans. I'm using the Back-Ups Pro 1100, 650, and 300

Pete

Katana Man · Post by **Katana Man** » Fri May 30, 2003 6:42 am

Do NOT get the APC Smart-UPS 750XL. I just threw down $800 smackers to get 2 of them, and they are not quiet. Makes me mad that APC does not mention the noise levels on their units. They didn't even mention that it has a fan. (Granted the fan only turns on durring power outs).

It has a random, on and off buzz occassionally. The buzz is steady during a recharge after a blackout. So the random occassional buzzing must be when it's trying to top off it's batteries. Buzz.. Buzz... silent... silent... buzz. buzz...

The 750XL does everything else correct though. Gives me 1 hour of run time with a 19" CRT monitor, filters out noise, cleans brownouts, surges, blackouts, communicates to my PC via USB, etc...

aristide1 · Post by **aristide1** » Sat May 31, 2003 7:44 am

So we're saying that there's no fan noise during normal times when power is on? That's all I really want from an UPS. The buzz part? Well it depends on how loud the buzz is.

scalar · Post by **scalar** » Tue Jun 03, 2003 11:34 am

UPS's use what are essentially very high quality, high capacity car batteries.

These are lead-acid cells, and there is a unresolvable design problem with them where they will slowly discharge and go bad over time. (This is why a car battery needs to be replaced every few years.)

The solution is to use what is called a float charger that constantly applies a very tiny charging current to the battery to keep it "topped off".

The UPS may be doing this intermittently, charging a while, then sitting quiety, then charging for a while, etc.

Also, please note that APC UPS's do an automatic self test once every two weeks. The UPS has a dummy load inside which puts stress on the batteries to see if they are still holding a charge properly. This stress test pulls a percentage of capacity out of the batteries, and so it will spend a few hours recharging after the self-test.

The usual way a UPS fails is that the lead-acid plates are corroding and losing energy production capacity, but if you don't use the batteries you never notice it. Then when it is actually needed and a load is put on the batteries, they can't produce enough power to keep the voltage up, and the UPS shuts down either very soon or immediately.

Shuriken · Post by **Shuriken** » Tue Jun 03, 2003 12:00 pm

My little APC 2200 Rackmount also has a fan. But it only spins when the power fails.

Post by **MikeC** » Tue Jun 03, 2003 12:12 pm

Instead of one big noisy one, why not 2 smaller quiet ones? S'what I have --500VA, 275W rating. Fanless, silent, cheap. 3 years running now. http://www.cyberpowersystems.com/500sl.htm Only had to kick in a few times, but they probably save the systems from any serious line fluctations too.

halcyon · Post by **halcyon** » Wed Jun 04, 2003 1:21 am

I think I need to look into APC UPS units. Powerware apparently makes quality units, but the line-interactive ones (that have true realtime filtering) keep that fan on all the time.

Needless to say, they are unbearable with a silent pc.

thanks for the tips!

cheers,
halcyon

Post by **Ralf Hutter** » Wed Jun 04, 2003 3:25 am

I have an APC BackUPS Pro LS500 that I cannot hear when my computer is running. It has a very slight transformer hum that you can just barely hear if the room is dead-quiet but it has no fan in it or any other type of buzzing noise.

My friend has a Belkin 800-something (it's a new one, the model # is F6C800) that has a very loud transformer hum and a pretty loud buzzing sound as well. I borrowed it a few weeks ago and it was clearly audible over the noise of my (fairly) quiet PC.

DeadBySundown · Post by **DeadBySundown** » Wed Jun 04, 2003 4:14 am

I use a 900VA Conext, which I believe to be just a rebranded APC. It's completely silent unless it's on battery. It hasn't got all the bells and whistles of the higher-end stuff, but the price was right, it has decent runtime, will put out 500W, and makes no noise at all unless it's running on battery.

http://www.conextproducts.com/ups/produ ... sku=CNB900