Never inside the closet!, lol. Now seriously, North of Hwy 7, you should consider an outdoor antenna since they have better gain and fight multipath better than usually omnidirectional indoor types. If outdoor is no option then an attic install is the next best choice due to being higher above ground. CTV is rather strong now , ch 9 VHF, so the issues might be related to multipath reflections but in any case consider an outdoor antenna that is also VHF capable since most antennas nowadays are UHF only. For an attic install (weather no issue), a VHF/UHF 15 CAD only antenna can be bought at Factory Direct , its branded KROSS, K0014, if I recall, and IMEx it performs rather well even compared to the famous CM 4221HD. It comes fully unassembled in its retail box but takes only 30 min to put together following the inside booklet. I would try that one first on the window on the second floor, and see what happens.
Chinesse made 20 cad versions are UHF only and depending where you live and other factors might give you reception on some hi VHF but it is not a professional recommendation , besides equally or more important ch 11 from Hamilton in the future will have to boost power and finally serve your area and who knows there is even a tendency later on USA to push TV from UHF to hi VHF to clear even more UHF spectrum for the wireless operators (but that will take 10 years or more probably).
General guidelines like using good conectors, shortest possible RG-6 cable run, and patience aiming using trial and error still apply.