Recommendations for darkroom air filter?

[Bob Wagner]

My darkroom is 400 cubic feet with a floor area 8' x 6'9. Does anyone have a recommendation for an air purifier/dust filter?
Ventilation is handled separately so this is just for internal circulation.

Thanks

[Doremus Scudder]

I have a twofold strategy. I installed two 12x12" lightproof vents in the walls when building the darkroom. I framed in the vents and sealed everything. One side has a removable cover; inside is a standard 12x12" furnace filter. When the exhaust fan is working in the darkroom, filtered air is being pulled in.

I also have a free-standing shelf-sized air filter (also with removable/cleanable/replaceable filters) that I use as well, especially before loading and developing film.

Mopping and wiping things down with a damp cloth helps a lot too.

Best,

Doremus

[Kevin Crisp]

I use a Honeywell Model HPA8350 HEPA filter. The filters will last years with occasional use. The non Honeywell filters available on Amazon are quite inexpensive. I clean the prefilter occasionally. It has really helped.

And my last step in loading film holders, in the dark of course, is to take each one and put it over the airstream with the slide pulled out and with the unit on "Turbo." I haven't had a speck of dust on an exposed sheet in years since I started doing that. It has some blue lights on the top of the unit and I cover those with gaffer's tape. There is also a 'light off' button which kills most of the lights, the rest are covered up.

I've found buy a used unit off Craiglist is a false economy. On two of the prior ones replacement filters became unobtanium.

[Tin Can]

I don't sweep or vacuum

I do limit dust by keeping my sinks damp

I hang all negs and prints ASAP over the wet sinks, no fans, no exhaust

I shut the door

in morning they are dry and dustless

[xkaes]

Ventilation is handled separately so this is just for internal circulation.

You need to tell us what this means. Is the "ventilation" filtered or not? That will make a big difference. How much "ventilation" / air flow is there. We aren't there. What, if anything, can you change / play with? Anything?

[Pieter]

Conway Airmega AP-1512HH

[Bob Wagner]

I use a small window air conditioner for cooling and ventilation with filtered intake, (a homemade box with a HEPA filter). I don't have a dust problem on negatives and film holders, I have careful procedures I use like many of you, but just want to keep the overall level of dust as low as is reasonably possible. Darkroom opens and is the pathway to the garage which is also a workshop, so dust does make it into the darkroom.
Thank you all for your suggestions

[xkaes]

So the only "ventilation" into the darkroom is when the "window" air conditioner is ON? If so, that needs some explanation. That's not going to get air in -- or fumes out.

[Naej]

Here is a suggestion, based on my calculation:

https://www.walmart.com/ip/Austin-Air-Bedroom-Machine-Midnight-Blue/103087185

400ft³/3 hours is 133.34ft³/hour.

This air cleaner does 125ft³/hour. So, it will take a little bit more than 3 hours to clean your room.