I got a roll of foil backed insulating material. mine is not bubble type i taped with foil tape to the metal ceiling and used wire cable and used that to hole it 1/2 in off the ceiling it works best if it is not up against the roof so it reflects the radiation cold or heat you feel coming from the walls. now having a foil looking ceiling was not to appealing so i got old fish nets and small Christmas lights and sells.starfish, sponges(from tarpon springs..lol) and strung the blue lights and one string of white lights with no direction just everywhere in a random pattern, then i hung the fish net i have old black and old cotton i got true old used not fake stuff. I draped that and put all the trinkets up in it . put the lights on a dimmer. I have a hot tub out there and when i used it most at night i turned on the lights and dimmed them down and it looked like stars . it was so nice laying in the hot tub looking up at stars and in day looks like well here are a few pics of that project
Hetty thats a great idea ...if you want something more permint (more money ...a lot more..) my grand parents where the fist in the states to get the ac unit that they put a small unit outside and run 2 lines in side and have a small unit with fan inside. now they didnt have to pay for it due to testing but now i thin they are $$ thousand or here is a link to what they had BUT they are 1400.00 kinda used if you add a room to live in and your ac is not big to cool that room;
http://www.goductless.com/Mits...
insulation
netting and final view.
I installed a new out let threw my block wall to pug lights in and a dimmer for it
when i did this 8 yrs ago you could not get this insulation at home depot now you can.
hope it helps