What size central A/C do I need for a 1,500 sq ft S.California home?

Answer 1

I think the best person to answer this question will be the AC company sales tollfree no. They can inform the exact size required after calculating the dimensions of your room. Dimensions also include the height of ceiling & the space occupied by furniture, cupboard & doors/windows in that room etc.
Further, incase you receive direct sunlight, through out the day & have no protection to keep out the radiations coming in from glass windows, then its recommended to go for one size larger, than suggested.

Answer 2

2 1/2 ton with a seer rating of no less than 13