Best methods for heating domestic hot water

[mtfallsmikey]

So, I just wanted to be different...instead of using a sidearm, or plate-type HX to heat domestic HW off the OWB next year, I looked into solar storage tanks, with built-in coils, 2/ 4500 wt. electric elements for backup,....downside was cost, ( $1,200 wholesale for a 60 gal. model for example) and only will do 20 GPH @ 90 deg. temp. rise....I'm thinking about a sidearm or plate-type HX, with separate circ/loop, tempering valve, would start the circ. by a flow switch; so when you open a HW faucet, flow switch kicks on circ.,and presto-chango...hot water. No standby losses. Anyone tried this method?..what method has worked best?
:greenchainsaw:

 

[ssupercoolss]

i'm not an expert here, but i am looking at my options for hot water. currently its a coil in my oil boiler that is going bad. i think without some type of storage your sidearm would have to be quite large, and probably incorporate some spiraling or something to maximize heat transfer. i think i am going with a 30 gal electric tank with a sidearm.