Is a home without a dryer exhaust dangerous?

You will get dryer lint all over everything and the humidity will get excessive and you will get mold and everything will eventually rot. The landlord will either install a vent or tell you where to put it and help ypu. If not, you can get a flexible hose and put it through a window. That is kind of tacky, that is why the landlord should do it right. Maybe the landlord doesn't know you have a dryer, some people don't, they go to the laundromat.