Canopy Fans Added!

[canadawest]

Well thanks to some consultation with Darren, and borrowing his hole-saw, I finally have some forced air cooling in my canopy. The 250W MH addition forced me to do something to help maintain tank temps.

Anyway, here's what I got:

2 - 12VDC .21A Cooling fans (Computer parts dealer, $14ea)
1 - RCA 500mA Universal (Voltage adjustable) AC/DC adapter (Home Depot, $20)

The AC/DC adapter is awesome, as it has adjustable voltages from 3VDC to 12VDC (3,4.5,6,7.5,9,12). Thanks to Darren's advice I wired up the fans in parallel to halve the amperage to each fan. Now I can run the fans at full steam (12V) or at a crawl (3V) or anywhere inbetween based on my cooling needs.

The best part is that at 12V you barely hear the fans running, and at 9V or less you can't hear them at all! Exactly what I wanted. And being speed adjustable is a bonus! :cool:

I'm a happy camper, and my livestock will be even more happy with more regulated temps, especially with summer on the way! :D

[sea gnome]

Hi Andrew, I'm glad you posted that as I have very noisy fans as well and was thinking about the super quiet icecap fans but they are a bit pricey. I think I'll check them out.(dc). Rachel

[AJ_77]

Hey, Happy Anniversary to you, Andrew.
About the fans:

Thanks to Darren's advice I wired up the fans in parallel to halve the amperage to each fan. Now I can run the fans at full steam (12V) or at a crawl (3V) or anywhere inbetween based on my cooling needs.

The best part is that at 12V you barely hear the fans running, and at 9V or less you can't hear them at all! Exactly what I wanted. And being speed adjustable is a bonus!

<font size="2" face="Verdana, Helvetica, sans-serif">1. Could you explain the wiring, including the adapter? Electrically challenged here...
2. What size fans? That's a very good price.

Thanks,

Alan

[Delphinus]

Alan -- two words for you: "Princess Auto"

:D :D :D

[AJ_77]

Tony - thanks! I recall the name, but did you get the quality of fans you were after? And what about sizes? Perhaps if I get it in writing I'll remember it this time. :D

Alan

[Delphinus]

All shapes and sizes and cheap. Yeah, my AC fans are loud, but the ones I have are absolute beasts, moving a fair bit of air. I think I paid $12 or maybe $15 each for them.

The DC fans are generally pretty quiet. But what's really keen about the DC ones is that if you use one of those multi-voltage wall-warts like is mentioned above, you can slow down the fan by switching to a lower voltage. Actually that's a really keen idea I never thought about that until I read it in this thread! But that's all the Icecap fans do, they just come with a thermocouple so that they can step down their voltage on their own.

Princess Auto has fans as small as teeney-weeney, to itty-bitty, to average, up to FRIGGIN' HOOOGE!! And blowers too. I bought this teeney-weeney 1" blower there once. I haven't the foggiest what I'm going to use it for yet, but it was just sooo cute! I had to have it.

If you want to go with AC fans (hey, hard to beat the convenience of just plugging them in, no worries about a DC power supply), you can get them there too, or, you might be better off going to a hydroponics outfit (go to Bumper Crop or Harvest Garden, both are good bets for this sort of thing), the fans they have look exactly the same as what I got at Princess Auto (110V AC version), but they're quieter. A little more expensive though, but it might be worth the investment if they make less noise than the surplus industrial beasts that I've got...

[canadawest]

OK, here's the low-down on the DC fan setup.

The two fans are 90mm (or 3.6") fans as I couldn't find 100mm (4") ones anywhere local. They are basically computer power-supply fans, and any computer parts dealer will have them. Any electronics or computer parts store will have these, but most usually only carry the standard 80mm (3.2") size case/power-supply fans, so be sure to look for/ask for the larger sizes as the larger they are, the more air they flow. I believe mine are 32CFM rated (flow @ 12VDC)

Specs wise, these are .21A 12VDC fans. The smaller 80mm fans were .14A 12VDC fans. I suspect that if you found some of the larger 100mm fans they would be somewhere in the .30A area.

Anyways, the RCA 500mA Universal AC Adapter I bought from Home Depot was perfect, as it has nearly double the amperage of the fans I bought, (.21A + .21A = .42A or 420mA) which is perfect for running the fans in parallel. (Parallel = same voltage but half current to each fan or 250mA/.25A going to each) Also having adjustable voltage (hence Universal) is a huge bonus for controling fan speed.

Anyways, they are a simple two wire job. Black/Red or Pos/Neg leads. In a parallel setup run your wires in your canopy and splice the red wires together and the black wires together from both fans. So basically you have one red wire that "Y"'s to both fans and one black wire that "Y"'s to both fans.

Now the Universal AC Adapter had a plethora of DC adapter plugs with it (hence Universal) but there is no need to cut them off. The outside of a female adapter plug is negative, and the inside is positive, so just stick your spliced red wire inside the plug, and tape the spliced black wire to the outside of the adapter plug. Voila, you're connected to the AC adapter without cutting or wrecking the adapter.

Now just set the voltage to whatever speed you wish to operate your fans at. The advantage is being able to have them run at 3V at night for minimal cooling (extremely quiet), and faster during the day depending on the ambient room temp, and the cooling needs of your particular lighting.

I have an open back canopy (2" space along entire length for cords, plumbing) so I have both fans, which are mounted on opposite sides of the canopy, forcing cooler room air into the canopy, which forces the warmer air inside to exhaust out the back. This is supposed to be much more efficient than trying to draw warm air out with the fans, and is supposed to keep your fans lasting longer as salt air is not passing through them.

Pretty simple, but effective cooling setup for around $60 total, plus 1.5 hours setup.

[canadawest]

Just another thought....

I also thought about the convenience of the AC fans (no wiring or cutting), but there is another advantage of using the DC fans. By running a pair of DC fans off one AC adapter, you only require one electrical outlet for the adapter and one timer. With AC fans, each will require it's own electrical outlet and timer! (although you could use a multi-outlet extension cord on one timer I suppose), still it's a hassle.

Not to mention the fact that AC fans require more power to run, usually twice as much as comparible-sized DC fans (which means more $$ on your power bill) and sound like airplane propellers in your house, due to the faster rotation and heavier bearings! :eek:

Cost wise they are almost the same. $55-65 for two DC fans and an AC Adapter or $60-70 for two AC fans.

[ 29 May 2002, 00:23: Message edited by: canadawest ]

[DJ88]

An easy work around for AC fans and noise is a rheostat. Nothing more. One plug can run both in the same manner as DC. Wire them up with teh rheostat and you can vary the speed of the fans. Slower speed less noise. etc etc.

I'll actually be going this route. Then when it's time to add in my controller(whenever I build it) I can set it up for speed control due to temp variations. YOu can do this with DC as well but I'd rather have the oompfff an AC fan has.

Another easy thing to build would be a temperature sensor based AC fan circuit. since all house electrical is AC, buy a thermostat. Instead of setting a heater to come on you can set it up so that as temp goes up fans get faster. and vice versa. I can't imagine it would be too difficult.

I'll let ya know as I have to do a fan set up with my new tank.

[StirCrazy]

another thing you can do with ac fans that make them handy is spice them into your MH power cord, that way they don't take a plugin at all and the switch on and off with your MH bulbs so you only get cooling when you need it.

Steve