I can't get enough sunshine either, I'm very outdoorsy. But the dark room experience is done to reawaken a gland in your brain. It's meant to help you find a new understanding of yourself. It's explained on the website. I just like to try new things.

I wanted to add: Mone Vidal has learnt about DR from Mantak Chia, who has learnt about DR from Ananda, 5 years ago, one month before us. So, they don't have such an amazing long time experience with it, compared with Ananda, who's the one who's brought attention back to this ancient practice. Mantak Chia has built an underground space just for DR in the Tao Garden, where waiters come with the glasses that can see in the dark to clean up the room and take you food. Cool, but pretty far from the original spirit of doing DR in caves and find the light within. In some Dzo Chen temples, like one in *Toscany, they have spaces for individual DR, I can bet much cheaper, even if I don't know if everyone can do it. In the buddhistic tradition they were doing DR typically for 3 years, 3 months and 3 days. I met a guy, indian, who's done 3 years of DR, very sweet guy.
I don't think you need to go to these commercial superstars, and I don't think you would like it either.

Just one first technical tip: how to cover the windows. You need first to cover them with aluminium paper, this is essential, then black thick plastic, last cardboard, always overlap junctions and use thick tape. You must prepare the windows in the light in order to see all little points of light, I tell you it is big chinese work. You have also to prepare the material at hand for when you enter the DR because typically, while your eyes get used to the darkness, they will see more and more the spots of light that at the beginning they couldn't perceive. It is a usual work inside the DR, I'm glad my husband is tall and we almost never have to climb a ledder, in the DR everything can be a bit more difficult (but it is also pretty fun). It is kind of sweet to take care day by day of the maintenance of your darkness.
Second tip: aereation. It is indispensable. If you don't have air conditioned, you can do with tubes, you have to shape them as S to intrap the light. Also this must be checked throughly before entering the DR.
Third tip: food. That is big mess. After trial and error, the best to use is a rice cooker. You won't be too happy with food in any case, unless someone from outside is kind enough to take you fresh food regularly. If such a friend exists fro you, it is a great mess to let him/her in. Forget about what you said of the mask, the skin absorbs rays and you don't want to ruin everything to eat one more apple.
Forth tip: when you get out, do it in the night , with sunglasses on , and be prepared, it is the most faboulous experience: you'll see the trees breathing, you'll see the light in the night, and how fairy-tilish this reality is indeed. You'll fall in love immediately for the world and at the same time begin to be longing forever for the DR behind. The moment you step out of the door it is like you enter the mirror of Alice. The world has a substance that you never saw before and you will never forget after. Something like a milky iridescence that is everywhere, and the intense feeling that everything is alive.

ciao
sofia

i ownder if this is anything like a sensory deprivation tank. i did this onece. you entere a competely dark tank, and float in a saline solution, no sound, no light, almost no awareness of your body, as you are just floating in body temperature water. very interesting experience. you can travel anywhere in your mind you want ot go. it like letting go and falling deep into your own consciousness.

afterwards i was totally relaxed, i mean absolutely calm for several days. i would have loved to do it again, but never did. of course this is just for a short while, not the extended period of time you are talking about, but i think it involves some of the same things.