fan speed control

[bravedave]

https://www.icmag.com/ic/showthread.php?t=237552&page=3
somewhere in that thread while they're talking about dude getting shocked by his variac

Seems to be a fair amount of misinformation being bandied about there. Never heard of a motor "compensating" for low voltage. Also seems counter- intuitive to think rapid on/offs is healthier for ANY device than voltage reduction.

In any case, I saw nothing about a fire. Did see speculation about overheating and overstepping a variacs listed amperage but ...

That said I use a cheap boxwave one on my cheap inline fan and it is noisy. I would never use one on my hurricane exhaust.

@crawlintbss no worries friend. You provided some good stuff.

 

[borbor]

After finally buying my carbon filter I plugged everything in to see where my temperatures were at, and just to appreciate all this money I spent.
I tried the speedster controller on the active air, as I've done before. It's definitely quieter around 60-75% but I do notice that hum, and it's annoying.
It kind of seems to me like a variac would be a smarter choice if I was using larger fans around 8-12" but I think what I'm gonna do is sell the active air exhaust fan and buy another 6" vortex. The one I've got for intake sounds about as loud as having a bathroom exhaust fan on.

 

[crawlintbss]

Interesting, i dont really get any noise problems with my Ventech and Speedster.

 

[az2000]

Would be interesting to know the temperature differential of those commercial temperature/speed controllers. That's the range between when it switches from high to idle. For example, if you set it to go full blast at 80F, how low does it have to go before it drops back to idle?

The Stego thermostat is 12.6F +/- 7F. That's as little as 5.6F (which wouldn't be bad) and as high as 17.6F (which would probably never return to idle speed after tripping the "full speed" condition). For a DIY, I'll have to keep looking for a thermostat with a tighter open/close range.

Just noticed this C.A.P. Custom Automated Products Digital Cooling Thermostat. It has a selectable 3, 5 or 7F differential. That's more in the range of what I'd say is acceptable. The Quantum (I linked to in my blog) appears to be a fixed 6F. I can't find anything for the Titan Mercury.

I need to call CAP and find out how they do their power reduction. If it's not clipping the sine wave, that would be a good value for $67 US. (If anyone wants to make the call, feel free. It may be awhile before I do it.).

 

[az2000]

In case anyone's curious, I learned that the difference in the temperature at which a thermostat turns on, and turns off is called hysteresis. For example, Stego makes a low-hysteresis thermostat. It is 7-degrees +/- 5-degrees. (Not good. Just showing there's nothing better in that direction.).

I'm thinking a home thermostat would work. I see Home Depot sells mechanical, non-programmable ones for $20. Seems like something for use in a living space would have an appropriate hysteresis. 2 degrees probably? That's probably where I'd look next if I wanted to control my Variac.

(Still plan to call a C.A.P. to see if they use clipped voltage like a cheap dimmer controller.).

 

[Sire Killem All]

good luck calling C.A.P. they are out of business. In reality it says right on amazon that the speedster is designed for brush type fans. So why do ppl buy them and promote them on here? cuz their cheap and work, i never read about anyone burning down a home or grown but i can say it will wear ur fan down, had no choice but to use it in last apartment, now 9 months later the fan makes a noise with or without the controller on it, tho could jus be because it is a cheap fan. any nice fan i say find i different way to quite it, i.e. insulated ducting, ridged duct, muffler.....

 

[az2000]

This looks like a winner. I found this page where someone raising chickens from hatchlings had a desire for very low hysteresis. Maybe 0.5-degrees F. He used this kit from Amazon for $15 which he said has 1.8F range between off/on. He goes on to explain how he modified it to get it down to 0.4F (had to deal with it being so "twitchy" that the on/off cycles created a buzz like the chopped-sine wave dimmers do, creating 60 on/off pulses per second.).

1.8F sounds reasonable for plants. I may order one of these and make the thing I diagrammed in the above post. I want to investigate residential home thermostats sold at Home Depot first. They'd be easier if they're in the 2-degree range.

good luck calling C.A.P. they are out of business.

Thanks. I googled about it. Sounds like they had a bad reputation. Something about calls for a boycott. I'll call one of the other two. I'm just curious how they accomplish speed reduction. The size of their enclosures indicates it's just clipping.

 

[borbor]

I shouldn't have put this thread in the noob section, since apparently you have to go through seven years of higher education and personally know all the guys who designed the fan and know the all the guys who designed the temperature controllers, to figure this shit out with a government grant and give a straight yes or no answer

how about this dial-a-temp thing?
https://www.hydrofarm.com/p/VTDAT
I've seen this advertised next to vortex fans, I've read that the manufacturer recommends that specific controller. Is this the same tech as the other controllers that start and stop the current really fast?

 

[bravedave]

I shouldn't have put this thread in the noob section, since apparently you have to go through seven years of higher education and personally know all the guys who designed the fan and know the all the guys who designed the temperature controllers, to figure this shit out with a government grant and give a straight yes or no answer

how about this dial-a-temp thing?
https://www.hydrofarm.com/p/VTDAT
I've seen this advertised next to vortex fans, I've read that the manufacturer recommends that specific controller. Is this the same tech as the other controllers that start and stop the current really fast?

Actually, I thought you got your answer right away. Yes, your original will work and yes its probably harder on your fan (and noisier) than a variac. The rest is pretty awesome free information that you can ignore or learn from. This new one you now show is also a box wave unit. That particular one has been around for at least 30 years. It is actually the same cheap one I mention using with my inline fan...very noisy in the mid range. I would be skeptical of any Mfr. (or hydro store) recommending it.

 

[borbor]

sorry didn't mean to come off like a dick but that's cool, so the ideal option to make my money go the farthest as far as silencing fans is probably something more along the lines of building padded little boxes and buying those duct muffler things?

 

[az2000]

Is this the same tech as the other controllers that start and stop the current really fast?

From the FAQ: "Do not use with blowers, booster fans, oscillating fans, etc." That's a hallmark of wave-clipping controllers. When you use one with a booster fan it will be like an on/off switch. No adjustability.

 

[borbor]

From the FAQ: "Do not use with blowers, booster fans, oscillating fans, etc." That's a hallmark of wave-clipping controllers. When you use one with a booster fan it will be like an on/off switch. No adjustability.

You know the sentence before that says "Our fan speed controller (ACSC) will work with brushless motors, such as the ones commonly used with inline centrifugal fans."

Do you understand how difficult that makes this shit for me to understand?

 

[az2000]

You know the sentence before that says "Our fan speed controller (ACSC) will work with brushless motors, such as the ones commonly used with inline centrifugal fans."

Do you understand how difficult that makes this shit for me to understand?

It will "work." I assume you'll get some buzzing just because that's what I've seen from two similar products (the "speedster" and Hydrofarm's "Active Air Duct Fan Speed Adjuster."). That last one says:

Hydrofarm's Fan Speed Controller was designed especially for centrifugal fans. This means it will help prevent damage to fan motors, ensuring longer life. (Meant for use with brushless motors, and all Hydrofarm inline fans, not booster fans)​

Designed especially for centrifugal fans. It makes my Hydrofarm centrifugal fan buzz like crazy.

I think we're dealing with 1) most consumers don't care. $20 is better than $60 for a variac. Buzzing? turn the stereo up. Fan fails in a year, replace the fan. 2) Hydrofarm sells more fans ruined by the dirty voltage produced by the clipper/dimmer controllers.

I don't understand all the motor types. Evidently there are some that the wave-clipping (dimmer-like) controllers work well for and voltage reduction doesn't. Apparently some overheat when run slow. My Hydrofarm green 6" inline fan is running at 40-50 volts and I don't feel any heat when I touch it. (Can barely hear it over the fans in the LED fixtures.). Not sure if reports of overheating are from running brushless/centrifugal fans at low speeds with the clipper/dimmer controllers. Or, if it's a different type of motor. I read there are some that start with the aid of a capacitor. There's an acronym for this, but I forgot what it is. They supposedly don't work well with lower voltage.

Sorry your thread got a little hijacked with temperature control, which you didn't ask about.

 

[borbor]

s'cool sometimes I really should make sure to medicate before posting to re-examine my mindstate.

selling more fans by having consumers ruin theirs with the controllers does sound like the correct answer, some shady apple type shit.

The vortex is super quiet though, I wanna start my grow off with the highest quality equipment I can (I added up all of my reciepts last night, I'm over 1000 deep without plants in the ground yet ) and since noise is the biggest issue for my landlord at this point, (my filter and airflow is enormous for a 3x3) I'm gonna have to buy a second vortex. At least I'll have the green hydrofarm for my next place

 

[az2000]

@Greengenes707 mentioned the Phresh Hyper Fan as having a different type of motor suitable for the dimmer-like speed controls. Supposedly these fans use less electricity, they're compatible with the less-expensive speed controllers. That might be a better option than pairing traditional centrifugal fans to variacs, especially when it turns into the need for thermostatic control. Instead of a DIY project involving thermostats and relays, one of the off-the-shelf products mentioned earlier could be used. (I think a person could go crazy and use multiple thermostat controllers with relays and have stepped speeds. Slightly warm = slightly higher RPM; warm = medium speed; hot = full speed. If you tried to do that with a typical centrifugal fan you'd be paying a lot for multiple variacs. Or, fixed step-down transformers.).

I can't find any significant info about these. They appear to be made by Phresh. But, when I visit Phresh's site there's no mention of them.

The only thing that concerns me is why it has a proprietary speed controller. It connects through a dedicated cable with a proprietary end. So, I'm not 100% sure a thermostatic controller could be inserted into the AC supply, or wired into the proprietary cable.

 

[Abiqua]

Can anyone recommend a good variable speed controller that will ramp up the fan to exhaust heat then return the fan to an idle setting?

Is that a thing or am I high?

Thermistor, set with your requirements or a bi-metal switch....skip the Arduino, unless you are down to for homework....

 

[az2000]

This looks like a winner. I found this page where someone raising chickens from hatchlings had a desire for very low hysteresis.

Found what appears to be a much better thermostat which can be incorporated into a fan-speed control:

​

It only costs $14 US and has some nice features like

• Non-volatile memory so it remembers its settings after a power outage.
• Adjustable hysteresis (1-10 degrees).
• Protective timer to prevent it from flipping too quickly from off to on again.

That model only controls a cooling device when the temperature rises above what you set. There's another model that also controls a heating device when the temperature drops below what a different setting. (There's another model that controls humidity. That could be wired into a fan-speed controller to increase exhaust if the humidity is too high.).

I updated my write-up with more info about this. I ordered a thermostat and relay. I should build a controller in a few weeks. I wanted to update this thread in case someone finds it someday.

 

[bellcore]

How is this one for controlling an Active Air 4" inline 167cfm?

http://www.ideal-air.com/products/accessories/ideal-air-fan-speed-controller.aspx
My main goal here is reducing sound. I already purchased and am on my second grow with it. It does help, but is there a better alternative? By the way I was using the Phresh duct muffler and just removed it and it isnt any louder without it my my particular application. Maybe a box around the fan would be better?

 

[az2000]

How is this one for controlling an Active Air 4" inline 167cfm?

It should make your fan buzz at low speeds. May also damage the fan motor. Read a few posts back about it, and how variacs are quieter.

I don't have that specific controller. I do have an Active Air fan and the Active Air controller which looks just like that one. It buzzes very much. But, if you've never heard your fan run at lower speeds with a variac (reduced voltage) type of controller, you might not recognize the buzz. You might think it's normal fan sound. In a quiet room the difference is huge.

 

[Silky Shagsalot]

i remember reading somewhere, that as long as the speed controller is solid state, that your equipment would be fine. snaps could answer this question quite nicely, but i'm not sure if he's still coming around anymore...