Canned smoke can also be purchased on Amazon fairly easily, some with free shipping.
Considering the season, (depending on which part of the country you reside) I would note any heating vents nearby the detector. You will want to avoid having the detector facing nearby vents (or directly above a floor vent.)
As rive said, height of the detector is important and is stated in manufacturer instructions for the PIR. Even a little dog could set off the detector if it is angled downward or installed too low. (or if the pet has a tendency to jump up on furniture in the sight path of the detector.)
Sunlight changes can indeed affect the detector. It is probably best to relocate the detector.