low priced HPS ballasts

[v1d9uy]

yea you could just use a spare pc PS and put it in the box and hook all yer fans up to that

[ChristmasGT]

awesome, If I could find some 120v fans that would work too right? and I wouldn't need an adapter correct?

[doublejack]

Yes, 120v fans will work straight from a power switch, no power supply required. One application that uses such fans is fireplaces - my fireplace has a pair of fans to send heated air into the room. These can be purchased to retrofit into existing fireplaces. That's just one option, there are many other types of 120v fans to choose from.

However, I believe 12v fans are going to be much quieter, granted they will move much less air. For noise reasons I'm personally going to use 12v fans, and I will probably run them at 5v or so.

[ChristmasGT]

I use an 80DB Tornado Fan in my computer I'm pretty sure I can live w/ it, I really don't want/need the extra wires in my box since its already a little too short and have to extend it and have the lense externally mounted.


how many fans do you think that I need for a straight through 17" setup? 2?


BTW thanks so much for the help

[v1d9uy]

well i plan on useing 2-3 one intake one to circulait and one for exhaust

[Guy Grotke]

How many you need depends on your design. I use one 120 VAC 65 CFM fan I got at Radio Shack. All the airflow gets pulled across the LCD surface, then over the lexan & fresnels, then into the light box, around the lamp, through a short duct, and then the fan pushes the hot air out of the projector through a light baffle. 400 Watt MH with magnetic ballast, and my LCD barely gets warm to the touch. Of course, I do use a pretty good Rosco Hot Mirror IR filter.

One important key to good cooling: Don't make a fan stir up hot and cool air together. That just distributes heat all over the projector. Use laminar flow from the coolest area toward the hottest. Air that has already reached 120 degrees F air can still keep a MH lamp "cool".

My fan mounting made a huge difference in the noise level. At first I bolted it right to the plywood side of my box: Worked like a acoustical bass guitar! Then I changed to a mounting that used high-density foam between the fan and anything rigid. Much much quieter.