I am flipping a bungalow into a purpose-built two apartment home. To allow for easy separation of utility costs, I'm installing dual HVAC systems, dual hydro panels, and pony meters on the water meter. This forces me to have two utility rooms (one per unit) and affects my usable real estate inside the house. Are on-demand water heaters a good investment? They definitely free up space but what do they provide in terms of efficacy, maintenance hassles, etc... are they worth it??
You did not specify electric or gas or the size of the unit by I use them often because:
-For smaller units they are cheaper and easy to install
-Take up very little space
-May require a breaker reconfigure as the usually require 2 30amp breakers
-In bigger properties with a long run say to the other side of the house, it takes a minute or 2 to heat up
It's a small bungalow... 800 sq ft per unit, with one heater per unit. We are putting in new panels, so a panel reconfig is not a biggie! :) I assume gas is preferred from a cost perspective?