Water Heater advice needed

[bczoom]

Eddie,

A couple have mentioned a parallel setup using 2 or more heaters.

Have you considered a series setup? I recall a couple people doing this.

You set the first tank relatively low (100-110 degrees) and have that feed the second tank which is set to the desired output temp. With this setup, the first tank does the pre-heat and establishes a reserve.

 

[buckle97]

<font color="blue">Have you considered a series setup? </font>

Now that's a great idea I havn't heard of before.

Lawrence

 

[Spiffy]

Since you have the power available to operate 3; I'd definitely wire it independantly controlled [so both can be on]instead the likely "upper lets the lower run when the upper isn't". This will give you much faster recovery. You might consider higher output elements too.


Longer term, you are right that good planning on a manifold will help, but fluids are trickly......stupid factors you just can't think of will come into play and cause uneven loading. Splitting them up would be perfect, but since you want to add units as you need them, a potential headache.

Another option would be series operation, but to keep bacteria from forming I think you want to be around 120F; however, then the second tank is only raising 10F (to 130F). If it were just for my resisdence I'd take it to 150F on the second one so you really get capacity [using less hot to cold, effectively increases capacity], but I presume you really don't want to deal with burn victimes. /forums/images/graemlins/tongue.gif

Good Luck! /forums/images/graemlins/smile.gif

 

[Spiffy]

I see I was a little late suggesting series.....oh, well! /forums/images/graemlins/cool.gif

Great minds think alike?! /forums/images/graemlins/crazy.gif /forums/images/graemlins/tongue.gif /forums/images/graemlins/grin.gif

 

[bczoom]

Not late at all. I just type really fast.

I am pondering your potential bacteria issue. Everything I see says it can survive in temps up to about 150 degrees.

Since it is for non-private use, I doubt Eddie can (or should) go to that temp.

Eddie, what is the source of the water (public or well)?

If there is potential for bacteria in the first tank (which I'm still questioning since of the amount of flow), I wonder if in the plumbing process, he should consider a bypass for either of the tanks. This will allow for maintenance (cleaning as well as replacement). There is no "down time". Just change a valve and the tanks is bypassed.

 

[Junkman]

He could go to the higher temperatures and then use a mixing valve to lower the temperature in the hot water line. This would make the how water go further and eliminate scalding problems at the user end. There is a solution for every problem if you take the time to think it through....

 

[bczoom]

Junk,

Good call but I thought those valve setups were pretty expensive. I see they're not that bad.

I did a quick search.
Using this site, I got the following prices.
Valves are $100 (give or take).
Check valve (for cold water line) is about $15
Hot water expansion tank is about $50-$60

Brian

 

[Spiffy]

You need 150F to kill bacteria, but I think 120 gets beyond its optimum reproduction temps. Installed a cheapo unit last year, seems it said something to that effect. Maybe either his water usage or water source do negate the issue anyway though.

Actually, I like the mixing valve concept, but just can't get past the extra complexity and extra fail point [though both are really miniscule factors]. If the bacteria is a concern, I'd definitely go this route regardless of series or parallel storage [either way, 150F+ feeding the mixer].

Good idea on the maintenance Zoom! Of course that gets me thinking back to parallel. Bypass valves can be setup in series too, but for more than 2 units, parallel is too easy.

Perhaps the exit shut off valves could be used as throttling valves. Just check the temps with a heat gun about once a month about a foot before the manifold and adjust accordingly [and so the weekest is always wide open; don't get into a vicious circle closing valves until no flow /forums/images/graemlins/wink.gif].

 

[Spiffy]

Nice link!

Another $80 per shower, but I sure like that pressure balancing valve too.

Aren't we good at spending other peoples money! /forums/images/graemlins/grin.gif

 

[bczoom]

</font><font color="blue" class="small">( Another $80 per shower

Aren't we good at spending other peoples money!)</font>

$80/shower? I was thinking a single mixing valve after it left the hot water tank(s).

Oh yea... If I can't spend my own, let's spend someone elses.