 |
 |
|
 |
 |
 |
 |
 |
 |
 |
 |
| |
REPP-CREST
1612 K Street, NW
Suite 202
Washington, DC 20006
contact us
|
|
 |
|
|
|
|
| Greenbuilding Archive for April 2001 |
|
| 307 messages, last added Tue Nov 26 17:25:16 2002 |
[Date Index][Thread Index]
Re: [GBlist] Zero Energy House on Washington Mall (fwd)
----- Original Message -----
From: "Dr. Carmine F. Vasile" <gfx-ch@email.msn.com>
>
> Malcolm: I haven't "ignored" anything and fail to see how your comments
> relate to my reply to Mr. Herbert and standard definitions of either
Energy
> Factor (EF) or Conversion Efficiency for gas, electric & oil water
heaters.
>
> I know source-energy is about 3.2 times that consumed by any electric
> water heater, but this fact doesn't enter into the standard definition of
> EF. Similarly, gas pipline transmission, compression & decompression
losses
> do not enter into the EF of gas water heaters. Neither do transmission
> losses between solar water heaters and their primary source; parked
> 93-million miles away.
Well I know that you know and I don't like to see you quoting reports that
ignore it. The gas pipeline losses are, simply put, similar to electricity
transmission losses. The power station losses are over and above.
It is quite clear that electric heaters use at least twice as much base fuel
as direct fueled heaters. However, fueled heaters are more complicated and
if the consumption over time is very low(obviously room for endless argument
there) then someone may consider the simplicity of the electric heater
justifies the additional consumption. You may argue that this may occur if
both a solar water preheater and a drain heat recovery system are both
installed. Purchase of electricity from a wind generator would complete the
package. Note that in my view, purchase of wind electricity for water
heating without the consumption reduction measures above, would not be
acceptable since there is simply not enough wind generation to go round.
>
> Are you aware that at least 2 utility field tests showed tankless
> electric water heaters could save 41% of both site & primary energy
consumed
> by a high efficiency tank type water heater. They still demand 3.2 times
as
> much primary energy; BUT 41% less than even high efficiency tank-type
> models. When they are used to backup solar water heaters, with DHR as
> illustrated in Bion Howard's March 2001 story "Designing a "Green Bundle"
> Water Heating System" (Energy Design Update, March 2001), the solar array
> are permitted to truly conserve energy instead of compensating for standby
> loss and energy dumped down the drain.
Of course on demand electric water heating will use less energy than an
electric storage system. No need to waste research money on that.
>
> Whether you and John D'Angelo like it or not, there were
> 36,667,000 tank-type water heaters in 1993, according to the AD little
> report summarized @ www.oikos.com/gfx/bundles.html. The same report shows
> less that .05% were equipped with solar arrays (thermal or PV), yet
millions
> of tank-type water heaters have been added since 1993. These energy hogs
are
> well-protected utility cash-cows.
The owners of existing tanks could probably slash the energy loss by
doubling the tank insulation at low cost as well as installing solar
preheaters and DHR, whatever the tank energy source.
>
> Contrary to your choice of this phrase: "...your direct fueled
> heaters..." I do not sell tankless water heaters nor do I own stock in a
> company that does. Melody Lutz & David Seitz do. Melody can verify the
> source of the 41% figure. I'm sure David has similar data.
I didn't intend you imply you did, I was just referring to the heaters you
had listed in the comparison.
My concern is clear. You appear to be promoting water heating by electricity
instead of promoting saving of energy by those already having electric water
heating. There are several ways someone with an electric storage water
heater can save energy. Increase insulation, use a timer, install DHR,
install solar preheat.
Malcolm
______________________________________________________________________
This greenbuilding dialogue is sponsored by REPP/CREST, creator of
Solstice http://www.crest.org, and BuildingGreen, Inc., publisher of
Environmental Building News and GreenSpec http://www.BuildingGreen.com
______________________________________________________________________
|
|
|
