No one is talking about whether these things like what the fan causes, will damage my components over time or not.

That's because without actually looking at what is going on with your line voltage and actually seeing it nobody is about to stick their neck out and say no.
No it will not! Without a doubt it will not.
Well maybe it will but that's a definite maybe.
Eventually the fan generated line disturbances will cause a total and complete meltdown.

Now you choose one of the above and run with it. Nobody here or anywhere can diagnose what if any noise on an AC mains line will do without actually seeing the line analysis of the power. There is no definitive yes or no answer. Believe me if I could give you a yes or no and feel good about my response I would. My best answer is I doubt it but if something does fail don't say I said things would be just fine.

Ron

 

Online or line interactive UPS? Online costs £4,000 onwards. Can't afford that obviously. The £400-£600 ones usually don't even state if they are line interactive or not even by leading companies like APC.

I will be plugging my PC into the UPS too.

No one is talking about whether these things like what the fan causes, will damage my components over time or not.

You might try a couple of these guys. Not to expensive.

https://www.alliedelec.com/product/...K1AE3X_WioFb8MoaMDu5__K03E1gjulhoC2h0QAvD_BwE