On Mar 1, 2006, at 11:20 PM, David Scheidt wrote:
>
> On 3/1/06, Randall <tr3driver@comcast.net> wrote:
>>
>>> Are there plain storage tanks available that you could plumb in where
>>> the old water heater was, and then use a tankless for heating?
>>
>> The tanks are available, but why ? You'd have to add a pump to
>> circulate
>> the water through the tank back into the heater, since otherwise it
>> will get
>> cold in the tank. And since you're still keeping a tank full of
>> water hot,
>> you lose all the supposed efficiency gains of the tankless.
>>
>
> One place that demand-driven water heaters really shine is where the
> input water is pre-heated, or partially pre-heated. For instance, if
> you've got a solar water heater, you can feed water that's 100F into
> the on-demand heater, and heat it to service temperature. If the
> water in the solar heater is already hot enough, you don't need to do
> anything.
This is somewhat close to my point, which I did a horrible job of
making :-)
If there's a plain 50 gallon storage tank where the old heater was, you
now have 50 gallons of refreshed drinking water for emergencies, in a
tank that should be much cheaper than a water heater that's unused
(assuming the old one was replaced due to structural failure). Then
after that comes the tankless heater. No recirculation. The water tank
is just emergency storage. A side benefit of the storage tank is the
water absorbs heat from the surrounding area, so maybe it's 55 instead
of 45 when it hits the tankless heater.
jim
|