My son likes idea of under floor heating. But we have one unanswered question. If for health reasons the domestic hot water must be over 60°C.
How can the floor be kept cool enough to stand on with bare feet. I could not stand on my radiator with comfort.
I know 80°C (Table 42.1) is max for normal metal radiators and 55°C for hand held the same temp required for Legionellae to die within 5 to 6 hours which I would assume same for standing on with bare feet.
With a radiator it switches on and off but with under floor heating I would not want to find whole floor warming up to 60°C then cooling down again like with radiators it would not be comfortable.
So how is it controlled? I realise of course the water could contain bacteria inhibitors for the central heating circulating water but if using solar panels etc I would assume it would all be part of same system.