Does the tea house have air conditioning? If not, does it stay cool in the hot weather?

Seattle doesn't usually get weather that is uncomfortably 'hot'.

It's pretty cool inside

nope

If I recall correctly there was not air conditioning. It was neber uncomfortably warm during my trip last September but I'm from Arizona so its a bit subjective. The area has plenty of trees and brick so it was usually quite a bit cooler than the outside temperatures.