Architect1776 Loc: In my mind

Depends on the space and how long you will spend.
A small exhaust fan ducted to the exterior for when in use.
Have your supply being sucked in going through a filter.
A mini-split system is good for when not in use or even when in use.
There are many more sophisticated things that you can do depending upon your finances.

TriX Loc: Raleigh, NC

Let me suggest ordering a copy of the Kodak book on building a home darkroom - a classic that has everything including plans. Amazon should have one at low cost. Also, even with an A/C that often recirculates air. I would insist on vent fan and a light baffle (for air intake) in the door. I would use good halogen floods with a hi rendition index instead of fluorescents.

Quixdraw Loc: x

You do need some ventilation, but if strictly processing Black and White, well, I never managed to poison myself across some decades of improvised, less than perfect darkrooms. Color is another matter. As to ventilation, someone turned mine on when I was drying negatives. Just enough dust to require a lot of touch up. Incoming air filtration and cleanliness of the room very important. Fun project!

repsychler Loc: Honolulu

Indeed!

repsychler Loc: Honolulu

Thank you, I’m not interested in processing color, since it seems way too complicated and hazardous. A lot of old movies show darkrooms bursting into flames, so I am looking at all the precautions pretty closely.
I took a class in photography in Jr college, but I don’t remember any smelling any fumes, but that was a few decades ago.
It has been fun gather the equipment, and it’s readily available too. I just picked up a never used Omega C760 and auto timer for $175 from a couple that set up a darkroom for their daughter almost 30 years ago- she never used it, and they basically threw a plastic bag over it and forgot about it.
I’ve gotten really nice notes in packages from EBay, thanking me for giving their old ceramic mixing trays a second life. Buying film in bulk and loading my own cartridges makes it even more fun and economical.
Best,
Paul

Quixdraw Loc: x

Wonderful time to set up a darkroom! You should be able to gradually accumulate the best of the best darkroom equipment for very little money. Great good fun!

Wyantry Loc: SW Colorado

In regards ventilation: a light-proof air inlet “trap” WITH DUST/PARTICLE FILTRATION would be wise. Also some sealing around ventilation inlets and outlets, electrical and plumbing.
Perhaps a fan system to maintain positive-air-pressure of filtered air. A HEPA replaceable filter is recommended.

I found that two of the major dust-creating problems in a commercial darkroom I helped build were:
1. Dust from ceiling sources (we ended up sealing ceiling areas with plastic film),
and
2. Dust from floors (we finally sealed the cement floor).

Perhaps “overkill” for a non-commercial home-darkroom, but DUST IS A PRIME ENEMY!

We also created an air-lock light-trap entry door system. (Dual door system with interlock to prevent both doors from being opened at the same time {unless bypassed}).

Oh, and BLACK or dark walls, and proper safelights! We made the mistake of having light-grey walls and ceiling—got light-fogging during printing.

And an outside indicator-light to let people know the room is in-use.

Also electrical switch-interlocks so white lights CANNOT be turned on inadvertently! (i.e. controlled by enlarger usage—if enlarger/timer master switch is ON, white lights CAN NOT be turned on).

And perhaps a separate niche (cloth curtained?) area for film tank loading.

That was all fifty years ago, and I do not recall the exact wiring, but it could be worked out fairly easily.

Ollieboy

My comment was a joke. Geez,.....

larryepage Loc: North Texas area

I would not paint the entire room black. There may come a time when having visual reference will be a big component of your equilibrium system. The darkroom i used when taking my photography classes had medium-light gray walls and even light sinks under the chemical trays. Of course, some of your choices may be limited by your choice of paper. We were using variable-contrast fiber paper, which allowed pretty generous safelights. Our enlarger stations had flat black partitions on three sides, and our bodies protected the third side. We also had dark chemical trays.

Download, read, and understand the Safety Data Sheets for the chemicals you plan to use. The biggest hazard with most print developing chemicals nowadays is the pH...the alkalinity or acidity. Ventilation won't help with that, but gloves will.

In general, the chemical of most concern is selenium toner. The risk is heavy metal poisoning, and it can enter the body through any route, especially the skin and respiratory system. Fixer is probably next on the list.

Tank developing film should be easy to manage with an exhaust hood over your sink and adjacent counter. I always loaded my film in a changing bag and didn't worry about room light. I never worked with bulk film, so you may need a station with switches to darken the room completely if the changing bag won't support that step of the process.

Longshadow Loc: Audubon, PA, United States

JohnSwanda Loc: San Francisco

I would look into local regulations regarding dumping photo chemicals down the drain. Exhausted fixer in particular contains silver, a heavy metal which shouldn't be dumped down the drain.

Quixdraw Loc: x

We are not talking about deadly poisons! Selenium toner did / does anyone use it? How many of us had darkrooms for a very long time and are still above ground at relatively advanced ages? There are many, many easy ways to reclaim the silver - the internet is your friend. Doom, clearly we are all doomed by the thought of yet another darkroom! Not!

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Try and get a "Cold Light Head" for your enlarger. Better contrast control. Modest temperature control is good to have. I had Beseler 5x7 with a fully motorized chassis (both focus and height were motor driven), and both a condenser head and a cold light head. I bought it used in 1970 for around $450. I just looked and a new 45mxt is almost $3K - damn!

TriX Loc: Raleigh, NC

Just some random thoughts (and images from my darkroom):

the classic Kodak round safelights with an OC filter and or the larger Kodak rectangular safelights with the same filter are excellent and can often be found at low cost

If you can pick up a cheap used one, a constant voltage transformer will insure your enlarger output is constant and predictable

A classic Graylab timer is awfully useful even if you have a timer for your enlarger (I have two in my darkroom)

A wooden tie rack is very handy over the sink to hang tongs and things that need to dry such as fil reels and graduated cylinders.

A sous vide cooker makes an excellent temperature controlled circulating water bath to keep your chemicals at constant temp. I like to have a number of graduated cylinders labeled with the chemical they contain to place in the water bath

If you don’t have a Dichro head on your enlarger, you’ll need a set of polycontrast filters if you use variable contrast papers.

I like the accordion type opaque containers for storing chemicals - allows you to remove most of the air above the liquid.

Plan on constructing some drying racks for modern resin papers. The plastic coated closet wire shelves work well for this.

If you can find one of the Paco rotary print washers, they’re excellent. The same if you can find one of the powers photopanel for water temperature control. If not an in-line dial thermometer feeding the wash water from a mixing valve will help keep the washing water temperature controlled.

You need a good enlarger timer - here’s a photo of a Bessler and a GraLab

And you need a good sink big enough for 3 or preferably 4 11x14 or 16x20 trays - Patterson makes nice ones, but not cheap - check with a restaurant supply for used in shallow SS sinks.

Regarding chemical disposal, unless you do a lot of processing, the little bit of developer and silver that goes down the drain is probably diluted so much that there’s not an issue, but if you have a septic tank, that’s a different story.

Sorry to be so wordy, but darkrooms are close to my heart - I love seeing the magic of an image appear in the developer and nothing quite looks like a silver B&W print.

TriX Loc: Raleigh, NC

I bought my Bessler 45 with a Dichro head and motorized chassis plus the timer and a Rodenstock APO Rodagon, the Bessler timer and 3 carriers for $150 at a thrift store some years ago - looks unused. So there are some real bargains out there on film darkroom equipment now that the world had mostly gone digital.