Washing at 60 for holiday lets

This may or may not be the wrong forum for this question but....

1. I have been told by someone I know that runs a pub with letting rooms that she must wash all bedlinen for her rooms on a 60 degree cycle. I don't know if this is by law, or because her pub chain demands it, and can't ask her unfortunately. I can't find any HSE guidance on the matter and wondered if anyone here knew? I can only assume this is for control of bacteria.

2. I run a holiday let business and we're expanding with three new shepherd's huts this year. We have decided to do our own laundry as we can't find a reliable, quality linen service locally, which means investing in several washing machines and tumble dryers. If I need to wash at 60 degrees, the cycle time will be a long one and I'd prefer to get the cleaners to come, strip the beds of duvet covers, sheets & pillow cases, gather towels and tea towels and towelling robes, and stick them in the wash so that by the time they've cleaned each hut, re-dressed it with fresh linen from store and so on, they can take the now-clean wash out and stick it in a dryer and leave it for us to retrieve later and send off for ironing (we won't do the ironing as we do have someone reliable for that). Hence:

a) Any recommendations for what drum size I should go for? Perhaps two machines with a 10kg drum, or three with a 6kg drum, or some other setup?

b) Any recommendations for what machine to buy, so that I can get a fast (but effective) wash at 60 degrees? The bigger machines all seem to take hours.

c) I read the article on hot fill versus cold fill. I assume that, if I could find a hot fill machine, I could save significant time by providing water that is already at the correct temperature?

Thanks for your help in advance!