Thread: Inexpensive forced air particulate mask

Looks interesting.
How did you buy?
Thru Amazon?
H.

My concern with these devices (especially the cheaper ones) is that they may not always supply enough air to provide sufficient over pressure to keep dust out when inhaling. This is especially the case for devices which use smaller fans such as the one shown. If users have to exert themselves while needing to use a powered respirator, around double normal air flow is required to maintain sufficient air pressure.

Either way - small particles can still get into bodies via eyes and skin so I don't see it as a solution for wood dust in a shed. Dust also settles on clothing so you carry some dust around with you even if you are not making dust. Then when you take the mask off and stand still your body heats a layer of air around it which rises carrying dust up past your mouth and nose. This means wearing a mask until you have taken you clothes off.

Shed dust solutions should start with extraction at source as early as possible ie when and where the dust is made. If this is not possible then something like forced ventilation should be employed. Masks should be the very last on the list of options employed.

I realize that working in some spaces like ceiling cavities has little choice but to use something like a respirator but if you decided to get one make sure it can deliver at least 6CFM or better still around 8CFM.

Originally Posted by BobL

...may not always supply enough air to provide sufficient over pressure to keep dust out when inhaling...

How is the dust going to get in?
The pump has a H13 Hepa filter and the mask is N95. I am not sure what route the dust is going to take to get to your lungs when inhaling?

Originally Posted by clear out

Looks interesting.
How did you buy?
Thru Amazon?
H.

Yes, Amazon AU, $84.11

Originally Posted by BobL

...make sure it can deliver at least 6CFM or better still around 8CFM...

The average human breathes 0.21CFM, where do you get 8CFM from?

Originally Posted by jimbo16

The average human breathes 0.21CFM, where do you get 8CFM from?

Resting. Sitting in a chair doing nothing.

When doing strenuous activity its a LOT more than that; potentially over 13 CFM peak
Inspiratory flow rates during hard work when breathing through different respirator inhalation and exhalation resistances - PubMed

I have a Cleanspace2 powered respirator that has max flow of 7 CFM and I can easily collapse the mask by breathing in hard.

AS EJ says, breathing is not a uniform airflow activity. For about half a breath there's no air going in but rather its going out, this at least doubles the air flow requirement during the "in" part of the cycle. But even then the air flow is not uniform. For bout a second at the peak of the "inwards part of the breath" the air flow requirement even for resting breathing is about 2CFM. If that amount of airflow is not provided the pressure inside the mask goes negative and contaminated air may sneak in past the edges of the respirator.

Then add even "moderate" activity.
Then add a battery nearing the end of its charge and a blocking filter.
I have done tests on a Triton full face respirator and it comes with a ping-pong ball in a tube air flow meter.
Not convinced this was sufficient to tell me what was going on I used a proper air flow meter and found it delivered about 6CFM when the filters are new/clean and the battery is fully charged.
With used filters, after about 5 of hours use the flow dropped to around 3CFM.

Used while cleaning out and sweeping up a fithy large shed floor (about 5cm deep of leaves, sawdust, etc, ~20 green garbage bags worth) the Triton respirator was "useable" with new filters and fully charged battery but a couple of hours later it was struggling to provide enough air for the effort involved. Cleaning the prefilter improved things a bit but not as much as I liked.

I have used a full face respirator for a couple of weeks while epoxy spray painting labs walls and ceilings. The respirator was hooked up to an air line supplied with filtered compressed air. The filter and a flow meter (like an Ar gas cylinder flow meter) were worn on a belt around the operators waist and it was recommended we use 5 or more CFM. Spray painting does not sound very strenuous but there was a some ladder climbing involved so it required more energy than it first seemed I only felt OK with the flow over about 6CFM.

Originally Posted by elanjacobs

I have a Cleanspace2 powered respirator that has max flow of 7 CFM and I can easily collapse the mask by breathing in hard.

The Cleanspace2 only has one source of air. This has 2. From the pump, and through the N95 mask.

Originally Posted by jimbo16

The Cleanspace2 only has one source of air. This has 2. From the pump, and through the N95 mask.

AS soon as any air is being pulled by the wearer through the N95 mask that means the pressure inside the mask is lower than atmosphere and more likely to leak round the edges. Thats why some people wearing N95 masks still can catch covid. To be more protected a full face respirator is worn.

Do you have a link to the inline filter regulator ?

My triton battery pack never worked properly from new but the helmet is comfortable. I've thought of tethering it as you suggest but as you say you'd need inline stuff to make it nice.

Damian, I have a similar problem. My Triton respirator battery pack is getting tired and "D" size NiCads are are about as common as rocking horse manure. Perhaps one could replace them with MiMh cells which are quite common and way smaller and lighter than the old NiCads.

Originally Posted by damian

Do you have a link to the inline filter regulator ?.

Are you referring to the compressed air filter?

If so that would have been about 15 years ago so I don't remember what the filter was.
Maybe have a look on line?

I remember it being expensive because it included an oil vapour filter.

RE: as my NiCd batteries are still OK I added a Li-ion battery pack to get a longer full Voltage operating time.

Testing out the Triton Full face respirator

Yes I was asking about the filter.


I had already read the thread about the battery substitution and it is very helpful. I had thought though that a high airflow from a remote source would be good.


I use pedestal fan positioned to blow dust out the door onto my yard. I imagine the wood dust breaks down and gives the grass something to munch on...Helps in summer also..

I had already read the thread about the battery substitution and it is very helpful. I had thought though that a high airflow from a remote source would be good.
I use pedestal fan positioned to blow dust out the door onto my yard. I imagine the wood dust breaks down and gives the grass something to munch on...Helps in summer also..

If there is the slightest breeze any fine dust will ride the breezes away from your shed. The half residence time of fine dust is about 30 minutes so even a 1km/hr breez will disperse the dust a long way from a shed/