Two questions about S&P inline fan (TD-100)

[BeautifulColas]

I've seen posts about connecting your S&P fan to a regular extension cord, and I noticed that the wires coming out of the fan are very thin, like PC fan wires, whereas the ones in an extension cord are usually much thicker (smaller gauge number, like 16).

I'm afraid of starting a fire if I connect the fan's thin wires to a regular extension cord's thicker wires. I don't know much about electricity. I'm afraid that the extension cord could potentially carry much more current from the wall than the fan can take, especially in the case of a spike. Am I missing something here? It obviously works, but how safe is it longterm?

Finally, the sticker on the fan reads: "Caution: Mount with the lowest moving parts at least 8 feet above the floor or grade level." But if we use it in a grow box, especially a smaller box, then that wouldn't be the case. Do they caution to do that to avoid fires? Is it risky to ignore this caution and run it in an enclosed growbox shorter than 8 feet?

Cheers!

 

[Folate]

Good post. I have a 150 that I need to wire up.
Folate

 

[gloryoskie]

Here's my 125:

Wired internally with a 16/3AWG cord. Motor is mounted in
a wall behind the grow box 48" from the floor.

3 years 24/7, so far, so good.

 

[Jhhnn]

The heavier wire of an extension cord won't cause any issues. In truth, it lowers fire danger from an overheated cord. The current demands of small fans are quite low. From the S & P site-

http://www.solerpalau-usa.com/pdfs/White Papers/TD Outside Air White Paper.pdf

Following basic electrical math, 26 watts divided by 120 volts equals .22 amps, so even the thinnest 18 gauge commonly available extension cords have way more than enough capacity. S&P mixvent fans also have internal auto reset fuses, from here-

http://www.solerpalau-usa.com/tdmixvent.html

The 8' height recommendation is to keep fingers out of the fan, basically, & also to reduce perceived noise. For best fan life, the fan should be placed on the coolest end of the ducting, pushing air through any major heat source like an enclosed HPS lamp.

Capische?

 

[BeautifulColas]

gloryoskie: nice setup with the silencer! It's very clean-looking. Do you find that the silencer/muffler makes a big difference? Looks like it's about 2 feet long. Because outside the cab, the fan is inaudible, but there is a loud wooshing sound, which I'm hoping can be rectified by buying a muffler. Thanks for posting the pic and description, although I can't really picture how you mounted it in a wall

Jhhnn: Thanks for the explanation, it makes a lot of sense. I was wondering about the hot exhaust air, since the fan says that you shouldn't exceed 40c, so I like what you wrote about fan placement.

Cheers!

 

[gloryoskie]

Yes, the muffler dramatically cuts the whoosh, mine is
4' long. I made it easily in about an hour with minimum
tools and gloves.


Also my lights are vented with a separate duct system.
The air being handled by the S & P is well within temp
limits.

 

[BeautifulColas]

Nice diagram Now I can visualize it.

You made that silencer? Wow, it looks like something you'd buy in a store! You say it only took you an hour and minimal tools to make it...impressive. Can you describe the process, or do you have any diagrams or links to teks? I tried searching for diy silencers before, but I couldn't find one that looks as clean and professional as yours.

 

[fatigues]

To making your own duct silencer, it's worth noting how Phresh makes theirs.

Phresh duct silencers use two principles in construction:

1) The length of the duct silencer chamber is 3x the diameter of the input collar. So a 4" duct going into the silencer results in a silencer chamber length of 12". A 6" input would yield a length of 18", and so on.

2) To the diameter of the collar, Phresh adds 4" to the diameter of its silencer chamber. This 2" all the way around the silencer chamber is lined with 2" eggshell acoustic foam. This foam is available off of ebay or locally in some high-end music supply stores at not outrageous prices - though it is clearly not cheap.

To the two main principles of duct silencers, you can add this:

3) Phresh tries to use aluminum everywhere it can instead of steel to reduce vibrations.

For all of that, the cost on the Phresh duct silencers is pretty reasonable. No as cheap as DIY perhaps, but still in the $65-$100 range. Depending on the tools at your disposal and the availability and cost of the egshell acoustic foam, it's not that bad a price for a commercial unit.

Performance wise, the Phresh duct silencer about halves the dB created by your fan exhaust. Given that dB is a logarithmc value, which increases/decreases by a factor of 10 for ever increase/decrease of 10 decibels, that's a very dramatic noise reduction in the field under actual use.

 

[gloryoskie]

Got the DYI from another member's post, don't know who.

"Got it all hooked up. Definitely attenuates the sound by about 50% or more. The rushing air noise of the exhaust is completely eliminated. I applied some stick-on insulation to the external length of duct, which further reduced noise. 100% worth the trouble of building.

There's still some noise coming from the fan and duct, but it's much less than what it was. Before, it was barely tolerable, almost as loud as an air conditioner. Now, it's a fairly gentle noise, which is completely canceled out if another device is running (TV, fan, etc). I'm still going to run the main ventilation fan 12/12 with the light, as realistically at night when everything's quiet I can still hear it pretty well, and don't like that kind of racket when I'm trying to sleep.

FYI, my muffler is 4" internal, 6" OD, and 48" long. Filled with poly, as it exhausts into the house."

You will need to buy:

1x 6" hard duct
1x 4" to 6" reducer
2x 4" starter collar
4' by 4' (or 4' by 6') Machine Cloth (Mesh)
Polyfill batting (like in pillows or stuffed animals) and Sub woofer boxes.
Steel Tape

 

[BeautifulColas]

fatigues, great post man! Very good explanation. And you're probably right, the commercial ones are not that expensive, considering how much time and hassle they can save you, especially if you're not very handy.

Now, the one that gloryoskie posted is a lot longer than 3x the duct size. I wonder if the much shorter commercial ones will be sufficient, or if 48" is overkill for a 4" opening. In the case that a commercial unit wouldn't reduce the noise enough, there shouldn't be a problem with ordering one more and connecting it to the other one, so that you have two 12" mufflers in a line at the end of the exhaust, right?

Oh and btw: Does it matter if an extension cord is 125V, and the fan says it's 120V? I'm thinking no, but it annoys me that they aren't equal, lol!

 

[gloryoskie]

The shorter commercial muffs are fine, no doubt.
I'm a DIY'er by nature/compulsion.

In my opinion, buy 2, check return policy
if one is enough.

125/120 no worries. Verify with a tech to be sure.