6 years ago I repaired my hot water
unit, thinking I might get a few more years out of it, so before it fails I want to make a replacement.
My plan is to make it fit into one of the rear locker, which is a little difficult to access. I have calculated that the volume of the HWS would be around 30 litres plus insulation
. The biggest issue is that the tank/locker is not very deep but I will have to live with that. My plan is to run a 600w 12v element and have a tube heat exchanger
that provides hot water
from the engine
and a tube/heat exchanger for the fresh water. The tank will be full of glycol/hot water.
The thing I cannot work out is how long to make the heat exchanger
tubes. I imagine the hot water unit will run at least 65deg C (150) and I need to be least 55C from the shower
. My shower
uses about 4l (1 US gal) per minute.
Has anybody experience in making these things or can help me with the calculations. The HWS and tubing will be all stainless steel