Control Panel

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=4687229

Hi mangeshkakade

There is an exhaust fan calculator here: http://www.louhoff.com/HVAC.htm

125 BTU is a fairly low volume of heat so you can probably get away with a small fan depending on the size of your cabinet. Also, check the components manufacturers specs for cooling requirements and base your total ventilation on the component requiring the highest amount of cooling.

Hope this helps you.

Have you considered a Vortex Cabinet Cooler? Nice in helping to keep dust out of the cabinets, uses very little air and does a great job. We use a number of them in our facility. Here's one example:

https://www.exair.com/

If you have a source of compressed air that you can use then as D-Tec suggested it might be worth looking at a compressed air vortex cooling tube.

I havn't used them myself but if your system is going into an area where contamination could be a problem they could prove to be very good as they are not only a source of cold air but can be used to pressurize the panel and keep contaminants out. The also have the advantage of not becoming clogged with dust a other airborne crap like a fan and filter.

This link will take you to the GlobalSpecs list of suppliers of compressed air vortex cooling tube.

Ahhh thanks for that link Masu, I've been wondering about how those vortex tubes work this week - its good to see that wiki doesn't quite know either!!!

John.

From what I have read elsewhere I don't think anybody knows for sure how they work. I must make the point of getting hold of one and playing about with it, apparently if you cascade them you can produce cryogenic like temperatures.

I have a CCD imaging unit on my astronomical telescope and the background noise created by stray infrared radiation in the CCD can be a real pain. You can use a technique called dark subtraction which works by taking a series of images with all the optics covered that are then subtracted from the real images, but you need to use different dark images for different temperatures. If you can add some sort of temperature lowering and stabilizing system that keeps the CCD at a constant temperature it makes things much simpler and produce clearer images. Most of the time it's done with a Peltier but a vortex tube might also be useful particularly as there are no moving parts like fans that could cause a vibration.

<...125 BTU...> per second? Per fortnight?

Most control panel manufacturers drive the <...fan...> using a simple thermostat.