I'm responsible for a church facility with a modestly-sized preschool and a small kitchen (licensed commercial). I have funding to junk the ancient boiler supplying the facility (hooray). But I have to support peak use of the dishwasher which needs 50 gal per hour of 140 degree water (it has its own booster to take it to 180). This gets used infrequently but for health department it has to work when needed. The only other use for hot water is some hand sinks in bathrooms. So my choices are:
-commercial tank -- at 140 degrees using a lot of kW (or BTU); while small (50 gal) it will be running 24/7
-tankless -- large expensive unit to supply the kitchen (and/or small point of service to supply hand sinks)
-combo -- wimpy-ish tank unit running 24/7 and then a booster in the kitchen to supply 140 degrees -- the hand sinks supplied by the wimpy unit
Wow is this a fun question or what? Not so fun for me though. I have the best plumber and best electrician ever, ready to support whichever choice we make.
What do you think?