Ventilate or Scrub

With all the talk of darkroom ventilation, air scrubbers came to mind.
I've been reminded of those who turn on the shower to clear the air.
At www.safelab.com click on, technical resources. Dan

"Dan Quinn" wrote in message
om...
With all the talk of darkroom ventilation, air scrubbers came to mind.
I've been reminded of those who turn on the shower to clear the air.
At www.safelab.com click on, technical resources. Dan

What? Scubbers are required where the absolute amount of pollutants become
significant in terms of the public health. That generally means commercial
applications. I cannot imagine where any darkroom enthusiast would ever need
such a thing. Scrubbers are a nightmare to maintain to say nothing of the
expense.

This is Horse Feathers!

PSsquare

In article , "PSsquare"
wrote:

What? Scubbers are required where the absolute amount of pollutants become
significant in terms of the public health. That generally means commercial
applications. I cannot imagine where any darkroom enthusiast would ever need
such a thing. Scrubbers are a nightmare to maintain to say nothing of the
expense.

This is Horse Feathers!

Or something like that. Yep. I see the perfect darkroom! Scrub the
air, polarize and ground all articles, wear white paper suits, hoods,
mask, cotton gloves, booties... Yeah, sure.

Chances are good that a small darkroom gets as much 'dust' from human skin
sluff, dander, and clothing than new airborne particles.

Spoting prints is good for the soul.

John aka jjs:

I think you miss the point, so let me be more specific. There is a big
difference between dust/static control and scrubbers, and I cannot agree
with what seems a repudiation of dust and static as a danger. Dust/static
actions capture the bad guys and pitch them outside. Scrubbers capture
chemical bad guys and neutralize them for safe disposal.

Elimination of dust and static is easy and bring immediate results in the
home darkroom. It is also cheap to control. Keep humidity up in winter to
reduce static. Keep the darkroom under positive pressure and filter
incoming air with a cheap furnace filter. Put an exhaust fan above the
chemical trays. Use tongs. Tape the edges of ceiling panels to trap
fiberglass particles. There have been frequent instances on this newsgroup
and in my photo club where dust was a problem and the solutions discussed.

OTOH scrubbing chemicals is technically difficult and costly. Air scrubbers
have in common with good darkroom ventilation the capture of fumes, but
beyond that the similarity ends. In large part, scrubbers benefit the
outside atmosphere only. They need to capture a significant quantity to
compare with what is emitted from many common sources like industrial paint
booths. They need a revenue stream to pay for the system. The quantities in
darkrooms are trivial to the outside air quality. The darkroom quantities
are like peeing in the ocean. Who could measure it? So, the benefit inside
the darkroom is ZERO.

Regards,

PSsquare


"jjs" wrote in message
...
In article , "PSsquare"
wrote:

What? Scubbers are required where the absolute amount of pollutants
become
significant in terms of the public health. That generally means
commercial
applications. I cannot imagine where any darkroom enthusiast would ever
need
such a thing. Scrubbers are a nightmare to maintain to say nothing of
the
expense.

This is Horse Feathers!

Or something like that. Yep. I see the perfect darkroom! Scrub the
air, polarize and ground all articles, wear white paper suits, hoods,
mask, cotton gloves, booties... Yeah, sure.

Chances are good that a small darkroom gets as much 'dust' from human skin
sluff, dander, and clothing than new airborne particles.

Spoting prints is good for the soul.

In article , "PSsquare"
wrote:

John aka jjs:

I think you miss the point, so let me be more specific. There is a big
difference between dust/static control and scrubbers, and I cannot agree
with what seems a repudiation of dust and static as a danger. Dust/static
actions capture the bad guys and pitch them outside. Scrubbers capture
chemical bad guys and neutralize them for safe disposal.
[...]

Good article. I appreciate the correction.

"jjs" wrote in message
...
In article , "PSsquare"
wrote:

John aka jjs:

I think you miss the point, so let me be more specific. There is a big
difference between dust/static control and scrubbers, and I cannot agree
with what seems a repudiation of dust and static as a danger.
Dust/static
actions capture the bad guys and pitch them outside. Scrubbers capture
chemical bad guys and neutralize them for safe disposal.
[...]

Good article. I appreciate the correction.

What is a good filter for incoming air or what can one adapt for this
purpose? And what does one use to move the air with?
For dust, apart for all the forgoing, has any one tried one of those water
pot vacuum cleaners? Apart for the noise would they work? Would need to be
going for a fair while to have any effect I would recon.

Safelab?! Kind of a bizarre mix of proselytizing religion [sic ..."Asia has
long been a stronghold of Satan ..."], US patriotism [quotes from Dub-ya, in
reality his not-even-American-speech-writer David Frumm] and lab
knowledge...I guess that's what's known in the lab world as chemistry?


"Dan Quinn" wrote in message
om...
With all the talk of darkroom ventilation, air scrubbers came to mind.
I've been reminded of those who turn on the shower to clear the air.
At www.safelab.com click on, technical resources. Dan

On Mon, 16 Feb 2004 16:56:43 +1100, "otzi" wrote:


What is a good filter for incoming air or what can one adapt for this
purpose? And what does one use to move the air with?
For dust, apart for all the forgoing, has any one tried one of those water
pot vacuum cleaners? Apart for the noise would they work? Would need to be
going for a fair while to have any effect I would recon.


I have a hepa filter mounted in front of the air intake with a
standard fiberglass filter on top of it to capture the bigger dust and
extend the hepa filters life.

Otzi,

You asked as series of questions.

What is a good filter for incoming air or what can one adapt for this
purpose?

I am using an American Air Filter pleated "Dirt Demon" that has about 50%
collection efficiency at 2.3 microns. There are lot of suppliers out there.
The package usually gives the collection efficiency. Collection increases
for larger particle sizes, so I am essentially getting most stuff about
arond 5 microns. (There are 25.5 microns in one thousandth inch, so that
seems adequate. A human hair around 100 to 150 microns, I thinkl.)

And what does one use to move the air with?

I am using a rotary fan built into a light proof baffle. Bought it from
Porters and built a box over the intake to hold a furnace filter. This puts
the room at positive pressure. I have a smaller centrifugal fan build into
a box and set over the wet sink to exhaust fumes. I pipe the exhaust thru 3
inch flex hose to the outside. The centrifugal fan is bathroom exhaust fan
that I boxed into to make it sit on a shelf over the sink. It's capacity is
about 40% of the incoming fan, so it does not pull a negative pressure in
the darkroom. So overall I filter the input for clean makeup air, capture
fumes over the sink and exhaust them.

For dust, apart for all the forgoing, has any one tried one of those water
pot vacuum cleaners? Apart for the noise would they work? Would need to
be
going for a fair while to have any effect I would recon.



Don't have any experience with what you suggest, but I cannot imagine that a
vacuum cleaner would move enough air. They are designed to create high
intake suction rather than exhaust quantities of clean air. Anyhow, the
noise would be terrible. At least, that it how it seems to me.

Good luck

PSsquare

"SofaKing" wrote

Safelab?! Kind of a bizarre mix of...

I did notice the RED-WHITE-AND-BLUE.
IIRC that front page was dated 10-?-01.
Post 9-11-01 is still out there.
If you come across a better site with more DIY insight let us know. Dan