HPM inline fan and duct 'kit'

[BaronS]

While browsing my favourite store (Bunnings) I was looking at ventilation I need now but will REALLY NEED shortly. The very helpful bloke from B suggested looking at an HPM 'kit' for my nephew's 'chemistry cabinet'.

 

The included 5m of 150mm ducting should satisfy my requirements for the cupboards, couple of questions though... (and I wasn't quite cashed up enough to buy it on the spot, $240, including fan)

 

What is the minimum 'turning circle' of 150mm flexiduct? I intend coming in through the back of the area above my red (flower) room, putting the duct through a 450deg turn as light trap, and ending the 'entry run' near the bottom of my 1.4m height.

 

I want a couple of additional light traps also. I intend, unless otherwise advised, to take the air out of the red room and feed it into the bottom of the blue (veg) room. The inline fan will then be placed above the blue room and exhaust out the side or back. Sound reasonable?

 

Would the flow of such an 'inline fan' be possible to vary? I don't think I need to move 350m^4/whatever through 850*550*1400mm (red room) or the 850*550*1m blue.

 

thoughts appreciated

[spartan]

as a general rule your favorite store doesnt offer very good value for money...

 

is the 350 CFM (Cubic Feet per Minute)?

if so, doesnt seem very good value... you Might want to consider shopping around

[BaronS]

I think it's the model R621/6L listed in http://www.hpm.com.au/Uploads/HPM%20ventil...%20movement.pdf

 

so that would be 360 cubic meters per hour, which I 'rough out' at something around 180 CFM.

 

I didn't notice on the pack but the pdf suggests it includes two grilles I probably don't need but might make things tidier. I was looking at such because they were next to the kit I saw and I'd be looking to pay the best part of $30ea for them, minimum.

 

So far I've sourced all equipment (which really is just lights, pots, soil, accessories) using over the counter cash transactions. If I'm paying a little more than necessary I don't mind so much. There's a couple of other local places I may be able pick up just the fan and duct from as separate items.

[BaronS]

BTW: I just found a post with Pipeman and Luke Skywalker discussing this same object in June 2003, at the same price.

[flatcat_auz]

$240 could get a centrifugal..............

 

 

Have you seen this? It will help you decide what size fan you need and if needed can filter.

 

https://cannabis.community.forums.ozstoners...st&id=46526

[420 HELI]

I think the ducting would need about 50cm to make a loop back on itself as you suggest. This would also increase your noise levels however...

 

6M black core ducting = $20.50

 

Ezi Air inline fan = $69

 

... discount hydroponic supplies on ebay.

 

:D

[BaronS]

50cm turning circle. That's sortta what I was guessing at too. Inconvenient because my vertical height is only 40cm where the duct will go. Hence the question.

 

Inlet is really OK. I can come in the top rear and just do a curve down and feed into the bottom of the red room. Outlet is also less requiring of this if I'm cascading the rooms, outlet will be from the blue room and I don't care if there's a little light leakage. The killer is joining the two spaces.

 

The alternative is either separate fans or a Y split and balancing flow on the two paths.

 

I'm not so much worried about paying an extra few bucks to avoid arranging stealth payment and delivery, and easy return if, say, the fan blows under warranty. Amortise the additional cost over the life of the box and it's pennies per oz.

 

Leaving the last question whether the speed of such a fan is controllable. Yes, I know fan controllers are available, the question is whether this type of fan is suitable for use with such. My total space between the two rooms is only around 1.2m^3 (~0.5 and 0.7).

[420 HELI]

Yeah, fan speed controller

 

The Y adapter sounds like the most practicle idea... if the cheaper inline fans dont have the airflow you require, they greatly increase flow and efficiency if you mount two together. Just an idea, as that would probably still be cheaper than some other options...

 

[BaronS]

I think I must have lapsed into speaking Biddleonian again, I am being misunderstood.

 

The Y would be for 1 fan to run the 2 rooms. Fan pulling out of the bottom of the Y to exhaust and each room on one of the arms. _IF_ I can't somehow work out a light trap between the two rooms and run them in cascade, where air already used in the flowering room comes into the veg before being exhausted.

 

The interest in speed control is because I reckon this fan at uncontrolled (full) speed is WAY OVERKILL for my small spaces.