Hi,
I live on the sunny side of Maui, and we have coconuts in the garden. I can't help you with indoor growing, but can tell you our winter temps are in the low 80's during the day and into the mid 60's during the night. Our humidity is usually in the 80% range. However there are many climate variations on the island and coconuts seem to grow everywhere except at the highest elevations.
Good luck with your plant - have you got high ceilings? I hope so! I have just planted a dwarf samoan coconut in the garden which is supposed to keep low enough to be able to pick the nuts easily. We have to hire climbers to harvest and trim our other trees.
Best wishes,
Jenny

Just heard this past week about one that was grown indoors in Seattle that got to be about 15' across. We have the lowest light levels of any major metropolitan area in the country, so if coconut palms can get that big inside a building here...

I brought a coconut Palm from Florida and when i brought it to chicago in july it was about 12 inches and now its in my room and its about 45 inches. In my Pot where the palm is growing, when ever i water the palm thies white little bugs come out of the ground and i dont know what to do.

I am tring to grow one in a pot in Hawaii, and I'm trying to figure out what kind of soil to put in the pot. I've seen them out here growing out of the sand, but I don't know if that is the only thing it grows out of, or if it requires other types of soil mixed in. What are you guys growing yours in? In response to your posts, I know it can get pretty chilly in the winter at night here, high 50's and it doesn't seem to bother them any.