I have been researching different aspects of the pj design. Now I'm onto fan types.

Have you wondered about the difference between sleeve-bearing fans vs. ball-bearing fans? I did, and found this helpful PDF explaining the difference.

Ball vs Sleeve Bearing

Summary: Sleeve bearing is supposed to be quieter, but ball bearing fans last longer.


P.S. Who thought I was going to say they might explode!?

Briefly mentioned here... about 6th post down, and the same link and info you posted was mentioned here. 16th post down.

I purchased a sleeve bearing Arctic fan, but do not have a ball bearing type to compare it against.

Something else to look into are different types of fans. All I've seen discussed is PC style fans.

Do a search on the net for "cross flow" fans. They are the long cylindrical fans used in photocopies, heaters etc.

I priced some but they were way too expensive new. I have seen them capable of 105 cfm at only 23db. In addition to this, because of the length, you can get a nice "full width of the box" draw from the slot for maximum level air flow throughout the entire enclosure.

I'd mount it at the top of the rear panel. Am still trying to find a copier or heater to butcher.

The other thing about these fans is that they are very reliable and last for many many many years.

Cheers,
Arkay.

check out my PJ pics I used a bathroom fan from Lowes hardware $13.00
120 volt rated at 50 CFM but I gotta tell ya Ive have 12 volt compuer fans rated at 50 CFM or more and they cant possibly move the air that this fan does. I think the computer fans are rated with no resistance to air flow.

I'm glad to see that we are on the same wavelength. I, too, thought that the PDF was interesting and wanted to share.

Unfortunately, there is so much information on this board that there are bound to be duplicates. (How many times do people keep bringing up the same Halogen vs. LED vs. Metal Halide lamp issues, or 12v vs 120v?)

What it really shows is that people are really excited about this concept, and they want to share and help each other out.



Well, just in general terms. Is it loud enough to be annoying when mounted in a pj? Or do you even notice it? Has it joined background noise?

Dunno if it is too load as I haven't built my enclosure yet - I will try to isolate it using rubber mounts to cut down on vibration. I'm really not that particular about the fan noise - if it is annoying I will just turn up the stereo. That is the same method a friend of mine uses for his car when it starts making annoying sounds.

The Arctic fans are rated well above what Brain has determined to be sufficient in air flow. If you need the fan to run quieter, wire in a pontentiometer/dimmer switch and turn down the rpm's. Make sure that you have a thermometer to monitor the lcd temp though.

Yea your right, I still can not understand why people are so concerned about the fan noise? Just build the darn thing. you do not even pay attention or hear it when watching a movie, you will have the sound on and up during s movie to get the full effect, why not just ask people who have built it and watching their projectors now? then maybe it will put an end to all the questions and people can get to building it. So i say if you have not built a projector and see for your self then you have no clue how the fan is not an important issue as you tend to believe.......

Just my thoughts, (but are thoughts from experiance)... LOL

Joe

Joe has an edge today.....I like it..LOL

There is a point where your brain just considers the fan to be background noise and gets engaged with the movie. There is another point where the fan can be distracting.

Then there's the point where the sound issue becomes an engineering challenge. How quiet can I make this? One thinks: I've built PCs that were really quiet. I should be able to do the same here.

Same reason people keep revisiting the cooling system. They're within spec, but they want to do better.

As for building the box -- I've got all the materials coming in, and I'm waiting rather impatiently for them to show up. In the meantime, I'm looking at each aspect in minute detail. It gives me something useful to do.

Kewl, you will be starting very soon..... you will love it.