Which of these 2 fans?

Hi, Am setting up a 1.2 x 1.2 x 2 meter tent. Worked it out on another thread and I need to push 80 CFM MINIMUM but was advised to get one roughly 400 CFM due to having a 1 meter diameter MIRO IV made parabolic (meant to be cooler than average parabolics and enhaces spectrums etc - not using a cooled hood)

Anyways I am getting an S&P TD Silent series. Which one should I get... the one which pulls 571 CFM on high power, or do you think the one which pulls 341 CFM on high power would be enough? Just thinking of keeping the tent cooled.

Any replies appreciated. Thanks.

bigger the better, as a bigger fan on half speed makes less noise than a smaller fan on full speed

My thoughts exactly. Just as it's my first time I thought I better double check. The replies ran out on my other thread Thanks man

Agreed with those above. As well, if you ever run into temp or humidity issues, you'll thank yourself for having the ability to crank up the fan speed.

Not only that, think future... almost every indoor grower I know almost immediately started planning bigger during their very first run, so buying bigger where budget allows saves you from having to buy additional in the long-run.

-spek

You can also go with the bigger fan and install it on a dimmer. This will allow you to control the fan speed aswell. Does depend on the type of fan you are using but most fans, blowers, inline fans can be put on a dimmer. I find a dimmer useful because you can tweak the sound vibrations that come from the fan. maybe a few rpms lower then full make it a little quieter. if sound is an issue this is useful.

spek9 said:

Agreed with those above. As well, if you ever run into temp or humidity issues, you'll thank yourself for having the ability to crank up the fan speed.

Not only that, think future... almost every indoor grower I know almost immediately started planning bigger during their very first run, so buying bigger where budget allows saves you from having to buy additional in the long-run.

-spek

Click to expand...

Yeahh true. I knew I did need the bigger one but every now and then you get somebody saying nooooo that's far too big lol. So yeah I'll get the larger size thank you.

And I know what you mean already haha I bought my set up for a 3 x 3 ft tent then decided it wasn't big enough already so sent everything I had back different directions and swapped for larger sizes, that's why it's taken a lot longer than it should have

Nice one!

Deja

Ammastor said:

You can also go with the bigger fan and install it on a dimmer. This will allow you to control the fan speed aswell. Does depend on the type of fan you are using but most fans, blowers, inline fans can be put on a dimmer. I find a dimmer useful because you can tweak the sound vibrations that come from the fan. maybe a few rpms lower then full make it a little quieter. if sound is an issue this is useful.

Click to expand...

Can i just correct you on that? Fan speed controller, not a dimmer There is a reason fan speed controllers are 5 times the price, they don't cause fires! AC fans need controllers, DC fans can use dimmers. I know this because i recently bought a dimmer for £6 and then found out they burn motors out, then paid £43 for a fan speed controller xD

Ammastor said:

You can also go with the bigger fan and install it on a dimmer. This will allow you to control the fan speed aswell. Does depend on the type of fan you are using but most fans, blowers, inline fans can be put on a dimmer. I find a dimmer useful because you can tweak the sound vibrations that come from the fan. maybe a few rpms lower then full make it a little quieter. if sound is an issue this is useful.

Click to expand...

Yeahh I am getting a variac for it, they are safe to use with the 'smaller' S&P fans apparently which I'm guessing this is classed as a small one. I wouldn't use anything else though to control the speed I'd be too worried lol. I have one here that isn't a silent series that I haven't ended up needing. I was just wondering... they have 2 speeds, how the hell do you switch from high to low without a controller? Lol cheers

Unless the plants are getting sucked out of the pots, you cannot go too big xD Just remember you need sufficient intake to cope. If your tent in getting caved in with the negative pressure, open up some of the flaps. You can use 90 degree pipe bends in the duct holes to stop light getting in if it is in a lit room during your girls nap time. You want a slight cave in, but if the fabric is getting pulled tight, you are straining your fan motor. As a general rule, whatever the tent recommends duct size, go an inch bigger. 1.2x1.2x2m recommends a 4" fan. So get a 5" (it is what i have on the same size tent) and it does a full volume exchange every 30-40 seconds at full whack. But if i have all the flaps and holes sealed and zip it up, you can see that sucker go like a crushed coke can.

If you have little flaps over the zips on the inside, i find just leaving the bottom horizontal zip open does the job without any light getting to your babies.

DejaVuDejaVu said:

Yeahh true. I knew I did need the bigger one but every now and then you get somebody saying nooooo that's far too big lol. So yeah I'll get the larger size thank you.

And I know what you mean already haha I bought my set up for a 3 x 3 ft tent then decided it wasn't big enough already so sent everything I had back different directions and swapped for larger sizes, that's why it's taken a lot longer than it should have

Nice one!

Deja

Click to expand...

I have a 440CFM inline in my 2x4x5' tent and when I turn up the fan full blast, it feels like it could suck a golf ball through a garden hose. I'm thankful though, because the extra horsepower I have in the dead of summer means I can keep my temps manageable.

-spek

Green Troll said:

Unless the plants are getting sucked out of the pots, you cannot go too big xD Just remember you need sufficient intake to cope. If your tent in getting caved in with the negative pressure, open up some of the flaps. You can use 90 degree pipe bends in the duct holes to stop light getting in if it is in a lit room during your girls nap time. You want a slight cave in, but if the fabric is getting pulled tight, you are straining your fan motor. As a general rule, whatever the tent recommends duct size, go an inch bigger. 1.2x1.2x2m recommends a 4" fan. So get a 5" (it is what i have on the same size tent) and it does a full volume exchange every 30-40 seconds at full whack. But if i have all the flaps and holes sealed and zip it up, you can see that sucker go like a crushed coke can.

If you have little flaps over the zips on the inside, i find just leaving the bottom horizontal zip open does the job without any light getting to your babies.

Click to expand...

Yeahh I am a little worried about getting the whole negative pressure thing right haha but I'm sure I will work it out Just wouldn't want to bust my tent right away lol. Sweet. The pipe bend sounds like a good idea. I was told that it would be best to make a hole in the bottom corner of the tent to suck some air through the bottom so it takes more heat out with it from the parabolic. How big would I make this hole in inches if I was pulling say 300 CFM? (I haven't opened up my tent yet but I don't think it has a hole in bottom corner (SJ-DR-II or whatever they are called)

Cheers!

haha you have the exact same tent i do. you have a roof hole in the right back corner, a small hole in the back wall, top center, a vent with a velcro cover on the lower center of the left wall and next to that another large hole in the lower corner nearest the front of the tent. i use the top hole for ducting, the back small hole for cables (these all have pull cords so you can make them light tight) and the lower left hole for running in my air line, power cords to the fan and the water pump, and i have this open but folded down so light doesnt hit the plants. the vent i have the cover so the top and sides of the velcro patch are sealed, but the bottom is kinda buckled out, so air can be drawn in. this vent isnt very good though, you need that lower hole open. this and i keep the door zippers down the bottom but leave a gap of about 12-15 inches of them open, this allows more air to be drawn in without letting any light hit the plants.

a tip for you, when you set this tent up, you have 2 crossing bars for the roof. one will overlap the other. make sure your lights are attached to the higher of the two bars, as the lower bar helps support it. if you do it the other way round, you might find your lower bar sagging over time. if this isnt possible for some reason, tie the two bars together where they cross. this will make more sense when you set it up. it is a tight fit, get the frame built first, then slip the floor of your unzipped tent under the frame, get that all in place and the corners tight in, then flap the tent over the top of the frame. stand inside the tent, and start pulling it in one corner at a time, starting with the corner that the zip ends at (once again that will make sense when you get going). The last corner is a bitch to get in, but dont worry you wont break it. just make sure the first 3 corners are all as tight as they can be and fully in place, then force that last sucker in place. then zip it all up around the bottom and install the internal ground sheet. after you have ripped your knuckles to shreds fixing the velcro in those tight corners, you are good to go. i cannot stress how majorly important that ground sheet is though, make sure you use it.

it is a great tent, have had it two years now and it is awesome. taken it down and put it back up half a dozen times.