Hot Water

• Pain threshold for a human is 106F [1]
• If water is 60F year round from a supply - does 39F rise (see Tankless Electric Water Heater) suffice?
  • 60+39= 99F.
• Average shower temp is 105F [2]
  • This article says that 99F is better, so you potentially avoid eczema
• It appears that 120F water is a relic of long piping - the hotter the temp the quicker your water will get warm. But for on-demand, lower temperatures appear to be better.
• Thus - minimize piping length to point of use. [[Seed Eco-Home specification is keeping heater distance to within 4' of point of use.
• Earth temperature is constant 30' below surface - this is called the mean earth temp. [3].
• Earth temp varies significantly with seasons - to full seasonal variation - at surface. [4], Thus, water pipes, at 3' or so below, show large variation of seasonal temperature.