Thread: Room air filters - are you happy?

Originally Posted by Green Beetle

Hello,

I'm either going to buy or build a room air filter like the ones at CT and H&F (Carba-Tec 650cfm Room Air Filter : CARBA-TEC).

I can buy all the bits from an industrial filtration specialist for about $100 and my sparky mate will wire it together with a remote wired speed controller for nothing. The filtration I can buy is of a finer micron that the bought models. 2 stage - cheap coarse filter protecting an operating theatre quality 1 micron pleated doova.

A simple micron rating means relatively little, you also need to know the efficiency of the filter media at the micron rating. Genuine HEPA filters start at 99.95% efficient at 0.3 microns - anything less than this and health benefits are minor. The bought ones from carbatec are really designed for keeping the fine dust off your finishes and only offer a minor health advantage over venting a DC to outside a shed. If you cannot vent outside (eg you live in a very cold climate) then they are worth having.

I have a tiny workshop with all the usual machinery and a 2hp dust collector in a sealed enclosure around an external awning window. So right now ... I can not see any dust in the air, but I can smell it and taste it.

Are they noisy, expensive to run, need regular cleaning/consumables, efficient?

I'd like to hear if any of you have experience ether building, buying or operating these devices. The regular contributor BobL is insistent on externally vented dusties, which I've done ... but I'm wondering if the next step is required. I have small children in the house above and am a bit spooked by the Bill Pentz website and all the other OHS reading I've done. With a negative pressure in the shop already (from the dusty), perhaps I've done enough?

I have made and used dozens of the HEPA filter units at work using HEPA FIlters from EMAIL AIR and other manufacturers. The HEPA filters are not cheap but the units are easy to make. They need about a 1/3 HP motor and a fan (usually squirrel cage type) that can hold a reasonable pressure differential (80Pa : NB not all fans can do that). Home made setups tend to be noisy and chew power. Serious Prefiltering is essential or the very expensive filter will block up and these are one use only.

There are some very nice and quiet fully functional commercial models around that only use 80W continuous and are 99.997% efficient at 0.3 microns - they cost about a grand but are not available in Australia - we bought 70 of them from the US a few years ago.

Thanks for the reply,

The company with the filters is Airepure Australia - The leaders in Commercial Air Purification & Industrial Air Filtration and I think their stuff is normal in the market. They have a second hand industrial fan which they're happy to sell me. It's about 40cm cubed with a fan of 8 blades perhaps at about 30cm diameter. Apparently it's suited to draw sufficient air for these fine filters. I'll check the kW rating to calculate the cost at my residential electricity costs.

I've taken your advice and vented the DC outside, but there is still dust escaping.

The coarse filter is about $30 and the fine filter is about $60 I'm guessing. I'm hoping to get the old fan for very little. I've got the wood and screws and glue. My sparky will give me a new controller and wire it up.

The filter company employ an engineer who is able to make the calcs, so I'll ask about the 80Pa, 0.3 microns and 80W rating. When I mentioned sub micron, the rep frowned and said "Really, that's very very fine indeed!" ... then led me to another isle.

I'll post the results.

Originally Posted by Green Beetle

Hello,

I'm either going to buy or build a room air filter like the ones at CT and H&F (Carba-Tec 650cfm Room Air Filter : CARBA-TEC).

I can buy all the bits from an industrial filtration specialist I'm hoping for about $150 and my sparky mate will wire it together with a remote wired speed controller for nothing. The filtration I can buy is of a finer micron that the bought models. 2 stage - cheap coarse filter protecting a quality 1 micron pleated doova.

I have a tiny workshop with all the usual machinery and a 2hp dust collector in a sealed enclosure around an external awning window. So right now ... I can not see any dust in the air, but I can smell it and taste it.

Are they noisy, expensive to run, need regular cleaning/consumables, efficient?

I'd like to hear if any of you have experience ether building, buying or operating these devices. The regular contributor BobL is insistent on externally vented dusties, which I've done ... but I'm wondering if the next step is required. I have small children in the house above and am a bit spooked by the Bill Pentz website and all the other OHS reading I've done. With a negative pressure in the shop already (from the dusty), perhaps I've done enough?

I have the Jet and I am surprised how much dust gets captured in the initial filter. This post maybe handy for you. It is fairly quiet and has a timer and is remote controlled. The hardest part was suspending it in the shed in the first place.

https://www.woodworkforums.com/f171/j...iew-3-a-80040/

Col