Can someone double check my calculations please.

[plastik]

Hi all,

 

I'm having a lot of trouble figuring out the best choice of fan for my new tent.

Ive been reading so much my brain is starting to overload and I still cant make up my mind so was hoping one of you nice people could double check my calculations please (mostly worked out with the Cannaversity calc.)

 

 

Tent -

1.5mtr x 1.5mtr x 2.0mtr (5ft x 5ft x 6.75ft)

= apx 25.0 sq feet

 

light 600w

CFM - 139

 

Light 1000w

CFM - 153.5

 

(Will be running a 600w HPS for the hotter weather but do want to upgrade to a 1000w HPS later on.)

 

So going on the 1000w specs the room requires 155CFM,

x2 that for pressure resistance via carbon filter = 310CFM,

x 1/3 for temps = 360CFM

x 1/4 for an extra meter of ducting 35 FCM

 

So that means I'm looking for a fan in the 400-450CFM+ range or apx 200 L/S, right?

 

I want something as quiet as possible so the Westaflex Mixed Flow fans look good. they are quiet and continuously rated, but Im concerned about running it with the static pressure load of a filter

I was told that people do use them for filters but wasn't recommended and to look up the data and make my own choice.

 

SEC1006, 150mm, 420-560 CFM, dB@3mtrs 27-33 (2 speed)

 

27dB is pretty quiet, but If trying to find a quiet fan should I get the next one up at 720-910CFM and use a speed controller to slow it down or run this lower model at its set speeds?

Im guessing the set speeds have been optimized as far as harmonics go so would be quieter all round?

 

 

Also been looking at the S&P TD-Silent series but am worried about the static pressure thing as well.

Read about lots of people being interested in them but not about many people using them.

 

Apparently the tents ports are 250mm, so can go way bigger on the fan/filter but it seems that Ill just be way over rating the tent if I go any bigger because like I say above the next step up is around 720-910CFM! or higher.

 

Which brings me to my last question, how quickly does a fans output exceed that of the filter, can you get away with much?

What I mean is, how many more CFM's over the filters rating can I get away with before it starts getting damaged?

 

Thanks in advance for any help!

Edited October 9, 2011 by plastik

[jimbojones5678]

Hmmm.....not too sure about your last question so I'll leave that to someone more technically minded.

 

I've always found Westaflex equipment to be really good so I recommend them.

 

The CF should help quieten it down as well, Using a fan controller is a waste of time in my experience but others might disagree?

I prefer to get as much out of the fan as is possible, if you're going to be running it at half strength, then go a smaller fan.

 

If it is a bit too noisy then I just leave a radio on - that disguises it easily and doesn't raise eyebrows.

 

Jimbo

[nitram]

hi plastik

 

I want something as quiet as possible so the Westaflex Mixed Flow fans look good.

 

I believe the "MixFlow" to be the best, The blade pull/push features are based on NASA's research on areodynamics I've done alot of reading on "noise reduction" and what I found out was that most noise is created when wind/air changes direction. This means that in your design stage one shold give long consious thought to letting air flow either vertically or horizontally then be "ejected and replaced activly or passivly.

 

Myself I have a "MixFlow" brand but I think "Westflex" have a copy.

:yiyang:

Nitty.

[plastik]

OK, so I have chosen:

 

150mm Mixed Flow fan with the low speed rated @ 420cfm

150mm Mountain Air carbon filter rated @ 396cfm

 

This should be suitable yes?

 

Ive looked around for a phat filter but am having trouble finding one, however I have read that the MA are a pretty good alternative.

[chook93]

Hey plastik have you got around to buying a mixflo 150mm yet. I see in there brochure they say the standard model is $149 for the SEC1006. It sounds like a pretty good deal. Not sure if this is retail or wholesale price plus GST though.

 

I myself bought an S+P TD-500/150 silent series this week. I thought they looked and sounded the part but $500, it is an expensive option. I must say it isn't as quiet as I had hopped but in all reality as far as fans go it must be one of the quieter ones.

 

I have only tested it out for 10 minutes or so, so can't give a big review on its performance as I am still getting everything set up. Definitely looks good quality and made in Spain, which has a lot to do with the price tag I think.

 

Oh and one other thing the wetaflex SEC1006 is rated @ 420 m3/hr not 420 CFM.

 

Just something to watch with your calculations but sure it will be fine none the less.

 

Would love to hear your feedback on the westaflex as I will keep them in mind if I need to upgrade or need a second fan in the future.