10 inch passive intake vent?

[thc24]

If you don't want to buy acoustic ducting you can get similar insulation to what's inside it called "Quiet Stuff" in various R ratings. R0.6 is what's typical for most acoustic duct, but if you can get a larger bat in the bag of Quiet Stuff (there's also another type made by the same company called "Green Stuff which isn't quite as good, but still excellent) and then wrap this around the fan and the ducting you'll get rid of an astounding amount of sound.

 

 

Gday luke skywalker,

 

silencing one of my fans happens to be my weekend project, any idea where i can buy some Quiet stuff or simular.

[cracker]

All good info based on sound reasoning. I'm familar working with fiberglass insulation but open to all options. The flex duct I have is lined with a plastic linner sealing off the glass. Again the suggestions are very helpful to me while I'm still in the design phase . Looked at a few attic vent fans but not sure how they will function. One was a 14 inch inline fan. It was mounted in a round galanized metel tube. It had blades, not the squirrel type blower. It was rated up to 1500 cfms. I will lose some of the cfms depending on the length and number of turns in the duct . I have an AC buddy but surely don't want to ask him about fans and carbon filters. He will know right off. Thats where Ya"ll are so helpful!

[cracker]

Just did a little research on carbon and uv air filters. Sellers of these units want a hella lot of $$ for them. Any practical way to build an efficient carbon filter yourself?

[Luke Skywalker]

Yes, you can build one, provided you can make it with a solid enough container, a deep enough carbon bed and can compact the carbon effectively. This is fairly easy to do, but it's a messy, not particularly nice job.

 

A few hundred bucks for a carbon filter that completely eliminates smell and lasts a couple of years is a small price to pay IMO.

 

pipeman Posted Jul 8 2006, 12:24 PM

If rockwool was at all dangerous there would be strict WH&S guidelines covering its use, and there aren't.

 

Ever looked at the plastic bag that rockwool comes in, both horticultural and insulation types? These contain very explicit instructions on safety, or at least the bags I've seen do. It's far better to use something with no potential problems in this regard which does the job of sound reduction effectively than to potentially harm yourself, even if the risk is small. It may well be that the safety of rockwool is greater than smoking bongs, but we're not talking about smoking bongs, we're talking about making your own silencer for your fan. I know that personally I'd rather use something with no dust or fibres which lodge in your lungs if you don't wear a mask.

 

Of course the price comes into the manufacturing and reasons for change, but it is fundamentally safer for the user, and still very effective in sound reduction. Don't you agree with that? Most people when building a home fan silencer don't take safety precautions that you may in the construction industry.

 

Since 2000, rockwool insulation was modified to make it safer, true, but this doesn't eliminate its potential for harm. They're safer, but not entirely safe. Any dust or microscopic fibre is harmful, particularly when you're in close proximity to large quantities of it as you are with fibreglass and rockwool. WH&S or OH&S requirements are different in every state, and some are more restrictive than others. I know I'd rather not take the chance that the manufacturers have artificially exagerrated the safety of something which has been known in the past to have health issues. Changing the formula is all very well and good, but if there is an alternative which is effective, why not use it?

 

thc24 Posted Jul 8 2006, 02:39 PM

silencing one of my fans happens to be my weekend project, any idea where i can buy some Quiet stuff or simular.

 

Try a bunnings warehouse, it may be on the steep side as you have to buy a large bag of it, but it's very, very effective. And safe to use without a mask. I'd suggest it may be easier (although possibly not cheaper) to simply get a metre of acoustic duct which fits over the fan body itself, and then a couple of meters of the fans flange diameter acoustic duct for each end, (or one end if you've got the fan mounted directly into the room) to help reduce the noise. If you don't mind taping and wrapping up for yourself though, go for it. Putting small holes in the ducting along it's length and then sealing the outside after the insulation with a solid sleeve further reduces noise.

 

Quiet stuff is bloody excellent, and I can't recommend it highly enough for sound reduction.

 

cracker Posted Jul 8 2006, 05:40 PMLooked at a few attic vent fans but not sure how they will function. One was a 14 inch inline fan. It was mounted in a round galanized metel tube. It had blades, not the squirrel type blower. It was rated up to 1500 cfms. I will lose some of the cfms depending on the length and number of turns in the duct

 

You won't be able to use an inline fan with a carbon filter unless it's rated far and above what you need. These kind of fans don't generate pressure like centrifugal fans do. They may move a heck of a lot of air, but they're not effective with carbon as the air simply washes back out past the blades.

 

You'd be able to use one with an ozone generator though, as this doesn't block flow of air significantly as a filter will. Take 20% off the air flow for a carbon filter.

 

With moving air, make sure you reduce as many of the twists and turns as possible, and don't put in a turn past 90 degrees as you'll drop airflow drastically. If you want to keep airflow to maximum, then keep bends below 30 degrees. Also, you want to stretch your ducting until it becomes smooth, not compressed like a concertina. You'll lose more airflow that way too.

 

The galvanised metal fans are very expensive for their ratings, although I must say they do last a long time. You'd probably pay more for a good centrifugal, but you'll be able to use it with a carbon filter very effectively and it will move large volumes of air too.

[Frazz]

yea i been down this road too cracker. ......i made a carbon filter outta a round laundry basket and a few odds and ends, cost about 80 bux worked all right for me but i had low odour plants......

wasnt game enuf to try it on anything 'very fragrant'

so i forked out about 450 bux and gotta phat filter and cent. fan....so IMO thats buggar all, to be rest assured that no-one ever smells what your doing....

only needs one freaky strain like ak-47/48 that stinks bad and in no time everyone around knows about it

Luke's dead right about the bladed fans theyre wont cut it with a filter

 

i figure ive spent thousands on scoring weed, but now i divert that money into my G-room and ive found it a marvellous investment ....but if you only wanna spend peanuts, hey thats cool....you may only get monkeys though

 

 

hey almost forgot the reason im posting ....heres a link to a room air-flow calculator http://www.hollandforge.com.au/en-us/airflow.pdf

 

hope it helps

[pipeman]

Luke I think your concepts of risk management and relative safety are skewed to say the least.

 

but, I think the point we are debating is largely academic and pretty much pointless.

 

to answer your question, the reason you would use rockwool for sound insulation is because its the best stuff for the job. If you think the health risks of using rockwool are enough to outweigh its superior qualities well thats your decision, but its not mine.

[cracker]

Who has a pict of a well sound insulated fan, whatever material used. Care must be taken when dealing with most things. The safety concerns listed by the Manufacture is to cover their buts but wouldn't be there if there was some level of danger. Follow the instructions if your not sure and take measures You seem best! THC, How do you plan to sound proof and setup your air removal?

[Frazz]

Just test them in the shop 1st and buy a quiet one.....theyre not all noisy, if you want wrap it up in a doona or buy the optional zip-up jacket to fit the fan

 

[thc24]

Thanks luke,

 

 

 

Bunnings it is then

 

I have insulated duct $$$ of 300mm but just had cerb collection and threw out 600mm 3 meters of

 

I plant to rivit muffler to motor wrap a layer of astro then insulation of sorts then astro layer suspended by a elastic cord . The Box i have fan in atm is ok but still get some vibration air noise is good now. Maby fan is dirty as i dont remember it being so loud and ive seen the odd leaf being sucked into exhaust.

 

R o.6 is what im looking for no probs mate isnt that the same rating as astro Industrial orange back. If so i fancy my chances of having a silent fan in days.

 

 

just rang Bunnings $45 for Quiet stuff 16 batts 75mm x 1115mm x 450mm about perfect. Made from polliester but was told fiberglass is a better silencing insulation. Must go and have a looksi.

 

Cracker hi mate i have a pic for you.

 

atm filter is set up back to front eg air neing sucked from room through duct then into muffler, fan forced through filter.

 

I hope to get a little more space and less noise by hanging carbon filter inside room small length of duct to muffler and fan (outside room) then down and out the hole i have in the floor.

 

Ill keep you all posted got some shopping todo

[cracker]

Thanks for the pict! That give me so many ideas. I didn't think of a unit like that while considering how to set it up! Edited July 10, 2006 by cracker