Hi there, I sympathise with you regarding noisy concentrators. I am on 5lpm when at home and have to be attached 24/7. Because of my litreage I have been given 2 machines which link togetheThe combined noise is so loud but I am lucky to have a spare room to site them in. I wouldn't like them in my bedroom trying to sleep. Trouble is we can't use our spare room for anything else, as it is too noisy! It has been re-named the oxygen room!!
I know my provider has machines that go up to 8lpm but I'm not allowed one because I have enough space for two. They are keeping the 8lpm machines for people who have smaller spaces/ need more than 8lpm. I can see their need is greater but the company should invest in more 8lpm machines.
When I went on holiday to a hotel they provided me with an 8lpm one as it was to be in the room with us.
I don't think yours should be vibrating though, mine doesn't. I was told it would be noisier on hard flooring and if it had to be on wood, tiles or vinyl, to put a rug under it to dampen the sound.
I use my cylinders when my tubing doesn't reach. It seems to work and they don't mind changing them whenever - I like to think I'm keeping a man with a family in a job. Such a nice man from Baywater changes mine.
I am, sadly, on too high a litreage for any kind of portable machine but I wish you well. Don't let it get you down.