[Top] [All Lists]

Re: Tankless whole-house water heater

To: shop-talk Talk <>
Subject: Re: Tankless whole-house water heater
From: Jim Franklin <>
Date: Thu, 02 Mar 2006 08:59:09 -0500
On Mar 1, 2006, at 11:20 PM, David Scheidt wrote:

> On 3/1/06, Randall <> 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.


<Prev in Thread] Current Thread [Next in Thread>