[Greenbuilding] Steam Shower?

[Joe Killian]

  ...And more to the point of how much energy is used total, take the 
easy way through:
   The total amount of energy used is the total amount of energy (heat) 
leaking out -
   Can't leak heat out of a cold tank, but definitely will leak heat out 
of a hot tank (this during periods of use or non-use).
   During use, the heat loss from the steam in the room and from the hot 
water in the tank will be the same whether it was heated from cold water 
or from nearly boiling water, only difference being whether it was 
supplied totally during the use of the steam room or partially much 
earlier.
   So the difference in efficiency will be darn close to the amount of 
heat leaking out of the hot tank while keeping the tank unnecessarily warm.
   Joe


On 1/10/2011 11:45 AM, Corwyn wrote:
> On 1/10/2011 2:08 PM, Keith Winston wrote:
>
>> I don't know how much water a steam shower takes, but I can imagine that
>> the power requirements would be somewhat reduced if you are flashing a
>> tank of hot water to steam vs. bringing cold water up to temp.
>
> Sure, but the energy requirements are the same.  Lest we have some 
> people still unclear on the distinction between power and energy.
>
> However,
>> the difference is only moderate, since actually flashing the water to
>> steam takes 5-10 times more energy than heating the water up to, say,
>> 180. Kohler can't really keep the water hotter than that, I'd assume, or
>> else they'd be risking a steam explosion... Unless I'm missing something
>> here...
>
> To be more precise, it take 970 BTUs/lb to vaporize water. (1 BTU/lb 
> to raise liquid water 1 degree F, of course)
>
>
> Thank You Kindly,
>
> Corwyn
>