Yes, call in the local health authorities for your own protection! I've never heard of living like that and if you're not sick yet, I'd be very surprised to hear you're still 'well' (if miserable) in a very short time. I've heard of Scrooges, but that's outrageous! Sorry I can't answer your orchid question.

LOL! Actually I've known a few folks who have lived that way just fine. Did it myself for a year when unemployed. However I would have to say it wasn't pleasant. It is rather extreme -- at least do 60's during the day. I could see a "heated" battle occurring over the thermostat. LOL Surprised you AVs are handling it. On to orchids....

Yes there are orchids that would likely enjoy your conditions -- with some temp modification -- especially since any lights used in a terr would raise the temps in the terr a bit. Most of the orchids would not be overjoyed with the 53 degree zone -- happier in the 60's. One question -- how hot does your place get in the summer? Many of the cool growing orchids cannot handle high summer temps. For this reason many folks who do cool growers use their basement where temps are much more consistent and easy to keep that way.

Do you have really good natural light?

Cymbidiums -- often large plants, they like lots of light. In summer they can handle being outdoors [provided you carefully harden them off as you would tomato plants started indoors]. They require a chilling period in winter in order to set buds. however after bud set, they generally appreciate warmer temps [at least upper 60's low 70's] to bloom.

Not as large but still much larger than Sophro, would be many of the Miltonias [pansy orchids] and Odontoglossums. [Odonts would, like Cyms, be too large for you average terr -- especially when in spike] Again they tyepically need cool temps though the 53 may be a tad too low. You'd have to research this a bit more. I can't grow them as I can't maintain the cool temps.

Many of the Sophronitis would still require a bit warmer temps than your 53, I think, but in a terr under lights you would likely be able to get warmer [again 60's maybe even low 70s]. you can use insulation around the back & sides of the terr to retain more of the heat given off by the lights if more heat is needed.

Most Masdevallias and Draculas would be options as well. [And some of the cool growing masdies have incredibly vibrant colors!]

Not sure about the Stelis or Aerangis ...

A deal more research in the orchid arena is on you docket I think. Your local library should either have some orchid books or be able to get some. You might even check Amazon for "cool orchids" or "cool growing orchids" and see if any books come up. Then write down the ISBN, and ask you library to get it/them.

There are of course lots of websites you could try find via a Google search I'm sure. Here's one species site to start you off ....

http://www.orchidspecies.com/

And here's one vender's site -- hold on to your Wallet!

http://www.andysorchids.com/

His plants aren't cheap but he has a nice variety, excellant healthy plants, and if you need help with something you've bought from him -- great to talk to and ask questions.

This should give you a start on you research project! LOL

Thanks so much for your good words!
I'll check out the vendors and contact them as well.
Meantime, I'll get a thermometer in the terrarium
and see what its temp actually is (under the lights)!
Thanks again
PS: I don't really live during the day in 53 deg house--I rush off to work in the morning and sit in a nice 72 deg office!