For articles pictures should be perfect quality, and such I always take on the site https://depositphotos.com/stock-photos/air-conditioning.html , at once you can see what the results are here on the subject of air conditioning. In this photobank you can subscribe and get high quality photos at a good price.
And those pictures that are freely available on the Internet do not suit you? They're probably not of very good quality... I don't know, I've never seen anything like that.
