How often should I change oil if reusing daily? At the moment I'm frying chips and protein 3 times a day daily using a fry machine. I'm using sunflower oil though could use others if needed but right now that's easiest to use.

The oil stays in the fry machine, not sure if it's air tight but i dont think it is and it also sits near the window.

I notice food particles in the fryer and fry basket but i guess i could clean that\pull it out with a sieve every 2-3 days.

Considering my heavy usage, how often should i change the oil and how often should I be cleaning the food out, will simply removing with a sieve be enough i still imagine there would be small particles remaining.

Also,  think I read that if it smells of other food you should change it.  However if you cook chicken in it it ay quicly smell of chicken, does it have to be changed in this case or can one just livewith the smell?
Oil does not wear out.  Unless burnt.  Try this. Drain or pour the oil into a coffee filter holder with the fine screen. Warm oil. It will remove most crumbs from the oil. Into a large mouth jar. Put lid on jar.  To supper clean oil run threw the paper filter. But that is slow to do. I do not see in America oil cans. With the filters in them of fine screen like used in small motors. Pour out remaining oil in bottom of fryer last. Wipe clean. The more crumb build up in the bottom the faster your oil turns dark as it burns.  Oil should last 6 months if filtered after use. Crumbs removed. By just adding oil lost.  To remove taste fry potatoes in it last.