DHW dilema

Timco

Turns out, Rainni offers a class on just this thing using a 50 gal elec WH as a buffer tank and a tankless to keep it hot. Works very well I am told. Class is on the 29th.Should be a sweet system.

Thnaks, Tim

Timco

So this cust needs tankless capability with him, wife and 3 kids (and one on way). Is fine with showering one after another, not two at once. Also needs recirc capability as 3rd floor has bath/shower. Any suggestions? I like the tankless for the amount of HW needed, but want some type of tank for the recirc and hand-washing/sink/dishwasher needs. House is forced air, and I have access to the gas line/service for proper gas service whatever I do.

Thanks, Tim

ALH_4

Tank

Sounds like a tank-type water heater would be in order. Why install an instantaneous water heater and add a tank? Instantaneous water heaters are not suited to low-flow, short-duration domestic water use, in my opinion.

Timco

I'd like to have the tank benefits (HW for small needs and re-circ capability) and the tankless benefits (endless HW). Can't I have both somehow without multiple water heaters?

Tim

jp_2

series

I'd think of putting a 2 gallon ele tank in series with the on-demand, down stream. this will also eliminate those cold 'slugs' of water. hook the recirc into the tank, on-demand won't know or care about the recirc .

personally I wonder about the effectiveness of recircs? how often are they just circulating hot water just to have it cool off? timers do help.

ALH_4

Armor

How about a Lochinvar Armor water heater? It's a lot more efficient than an instantaneous and is basically the setup you're talking about.

[Deleted User]

the last article

i read did the math on recircs, and unless you have a ridiculously high water cost for your area, they won't pay themselves off in your lifetime regarding 'wasted' water. but for the convenience of not having to wait for hot water, that's an emotional issue. and i heard of a related?, funny anecdote about an impatient guy standing in front of his microwave while heating a cup of coffee;
"c'mon, hurry up, i don't have all minute!"

Derrick Ellefson

Mini-Smart

Instantanious Indirect Check it out on Triangle Tubes web site. I think it can do 3 GMP @ 90f rise> It doesnt use a flow switch so you can recirc. You can use a aquastat or a NTC sensor tied to a Prestige and see the DHW setpiont on the boiler

jp_2

poor mans boiler/indirect

sounds like a lot of trouble to mimic a standard hot water heater with a small increase in efficiency?

what about an electric 10 gallon tank plugged in? will use a small amount of electricity to keep it up to temp, but will be fed by the on-demand.