Changing a fan on a DVR

The cooling fan on my DVR is getting very noisy. It is a 50mm 12v DC 0.7W fan and the closest match I can find locally is a 1.2W fan at Maplin (code RY86T). Is the extra power needed likely to be a problem?

I assume (but may be wrong) that the 0.7W fan is fitted due to cost cutting and bulk buying in the manufacturing process and not due to the PSU limits.

Adam

Reply to
ARWadsworth
Loading thread data ...

I replaced the stock fans on my HTPC with replacements from

formatting link
had sizes I found difficult to obtain elsewhere, and are very quiet, that said I can't see a 50mm fan on the site now.

I doubt it.

Reply to
Andy Burns

I wouldn't think so. If you ever buy from CPC, they probably have one.

There may be increased noise.

Reply to
Bob Eager

In message , ARWadsworth wrote

Not all fans are equal and some are very noisy so it's not just power that you need to consider. For a computer noise may not be an issue but may people complain about the noise made by a fan in a PVR/DVR that sits in a box under the TV. The noise figure is often directly related to the airflow figure and a lower airflow means lower power.

Probably no.

Try

Maplin fan

30dBA noise, Power 1.2W Quitepc fan 22dBA noise, Power 1.08W but with a lower airflow than the Maplin fan.

You may also need a series resistor to make the fan run slower/quieter.

7V version

Try also removing the existing fan and then the sticky label or plastic cover over the bearing and put one drop thick engine oil (NOT WD40) in the bearing. Cleaning all the dust off of the fan may also make it less noisy.

Reply to
Alan

The lower power one may have been chosen for quietness as well. Small fans can be extremely noisy and at a frequency range that will be intrusive.

An example of this is the small fans (40mm IIRC) that are used in 1U (44mm high) rack mounted servers beloved of hosting providers. Cooling on these can only be achieved front to back unless they are spaced with a gap in between and that's undesirable for space reasons. Additionally, there is a row of disk drives across the front and therefore a fair amount of heat. Usually in the middle there is a row of these small fans, sometimes even two deep. In some cases, one could imagine that Pratt and Whitney were the manufacturers.

For a DVR, one needs virtual silence , so small low powered fans are the order of the day.

It's also possible that there is some electronic speed control based on temperature. Another trick is to apply the rated voltage at startup to get the fan turning and then to drop it back to lower voltage for quieter running. The control electronics may only be able to support a lower powered fan.

If you can't identify the precise spare, then take a look at the label on the fan itself and identify the manufacturer or the part number. Sometimes the same part number is used by several manufacturers (one chinese manufacturer makes and the others private label it). At any rate, a Google search on the part number or manufacturer will usually find a web site, hopefully in Engrish, and from there you can get the spec. From there you can look for an alternate or possibly a supplier

Try if you can to get a fan with ball bearings or ceramic bearings rather than sleeve bearings as these seem to last longer.

Having said that, 50mm is not one of the most popular sizes so there may not be a huge amount of choice.

Reply to
Andy Hall

As I cannot get a new fan today I'll give the oil suggestion a go this afternnoon after the hospital visit to see my Mum. I have 40 litres of

15W40 diesel engine oil in my shed. It is my assumption that the bearings are failing on the old fan but I do note your point about the different noise outputs on new fans.

Cheers

Adam

Reply to
ARWadsworth

WD40 is actually good for cleaning out the old oil and muck. A drop applied, and then absorbed back into kleenex will draw out the old oil/muck. Repeat a few times. Then allow to dry, and then re-oil. (Don't run it for any length of time without re-oiling -- although it might appear that WD40 alone fixes the problem, it's not a lubricant and you would be running the bearing without any lubrication.)

Sometimes the dust build-up is actually responsible for what might sound like a bearing noise.

Reply to
Andrew Gabriel

Yes - my Acorn RPC has one of those on the PC card which is a 586 type. I didn't realise just how noisy it was until removing the card which I don't use anymore. Acorns produce so little heat you just about get away with only the PS cooling fan which is a great deal quieter despite being larger.

Reply to
Dave Plowman (News)

Now imagine 6 or more of them per server, about 40 servers per 19" rack, they generally come on at full tilt and all being well are able to idle down after a minute or so, once they realise the A/C is doing OK.

Reply to
Andy Burns

Cheers for that. The fan is easily identifiable (Sunon KD1205PFS3) The first google hit shows

which is indeed a sleeve fan and I am sure the bearings are on the way out. I was hoping to puchase an equivalent fan locally than mess about with mail order. I will give the RS website a look later as I will be in Leeds next week and will pass their store on my travels.

Adam

Reply to
ARWadsworth

Larger fans generally can run more quietly for a given amount of airflow because of the lower rotation speed if under run.

Doesn't studio/control room equipment tend to use this trick (at least where it is located in noise sensitive places?)

Reply to
Andy Hall

This is why machine rooms often have ear defenders by the door.

Reply to
Andy Hall

I have my own supply for those that don't.

Reply to
Andy Burns

which

Sadly RS's site is down for maintenance until Wednesday. However I did look in their paper catalogue for you and there isn't a lot in

50mm. They seem to sell Papst in preference, but there was only a sleeve bearing 50mm 1W fan.

The Sunon fan is rated at 35dB A, I notice. This seems a lot in comparison to most which are at around 25-27 so I suspect the measurement method is different.

Reply to
Andy Hall

You'd hope so, wouldn't you? But you wouldn't believe the racket the cooling fans make on lots of lighting gear where the PS are just plonked down on the studio floor. Perhaps it's made with pop concerts in mind.

Reply to
Dave Plowman (News)

A drop of oil has quietened it down.

This will give me time find a new fan next week.

Adam

Reply to
ARWadsworth

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.