Electric water heater is the instantaneous type and it works well if it concerns you coz some of the water heaters in Hong Kong are the storage type ones. Aircon works well too. One thing, the shower and the toilet and the washing basin are all in one cubicle without a shower curtain or anything to seal out water from the showering area. So you get a washroom floor all wet after shower, which i really don't mind but would be perfect if it wasn't so. Oh yes and it would be nice if the ventilation fan could run faster and stronger. Other than this minor thing, the room has the quality of a hotel room with a homey feeling minus the dry sleekness and luxury of a hotel room which I dislike. Nice stay and very communicative host!