I'm looking to install a window AC in my son's bedroom, which is about 120 sq ft. The guides that I'm reading suggest a 5000 BTU unit due to the size. However we live in the high desert where the summer temperature gets > 100 degrees (F) at times during the summer. Also he has several reptile terrariums in his room that require lamps which also heat up his room. In this case would using a 6000 BTU AC unit be more appropriate?
My 180 sq ft. home office/spare bedroom is in the room next to his. I use a 6000 BTU unit and it chills this room no problem. So thinking of getting the a simular sized unit, but don't want to oversize if that's going to cause problems.
Thanks in advance for the advice.