Mini-split hot water heater

[morphector]

I've been lurking a long time on here reading a couple of it water tank modification, I've decided to take to go for it.

Found a nice 10 years old Fujitsu rebranded as Friedrich ductless unit for 100$cad on FB marketplace.

I want to keep the electronics of the indoor unit and just replace the coil for a homemade coil inside the tank.

I measured the evaporator and there's around 75 feet of 1/4 copper tube in it.

Unit is "quite permissive" in terms of length of line set from 6 feet to 49 feet without having to mess with refrigerant charge.

I calculated the minimum and maximum cubic in of total volume for the line set+evaporator allowed, a 50 feet line set from an install kit is right in the middle so I'll make my evaporator from that line set and use a 1/4-3/8 flare adapter.

We are pretty heavy on hot water usage, installed an energy meter on our hot water heater and it's consuming between 10-15kwh per day

What do you guys think about this?