Greenbuilding Archive for April 2001

307 messages, last added Tue Nov 26 17:25:16 2002

Re: [GBlist] Zero Energy House on Washington Mall (fwd)

• To: "Dr. Carmine F. Vasile" <gfx-ch@email.msn.com>
• Subject: Re: [GBlist] Zero Energy House on Washington Mall (fwd)
• From: "John Herbert" <john.herbert@kelcroft.com>
• Date: Sat, 28 Apr 2001 11:41:23 +0800
• Cc: "Greenbuilding" <greenbuilding@crest.org>
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• Disposition-Notification-To: "John Herbert" <john.herbert@kelcroft.com>
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• Reply-To: "John Herbert" <john.herbert@kelcroft.com>

Dear Dr. Carmine F. Vasile,

<snip>
> I used conversion-efficiency values used by a NIST (then NBS)
> consultant in the DOE Grant Evaluation of our DHR system (GFX),
> Recommendation No. 382, OERI No. 009925 Dec. 1986.
<snip>

A US study dated back 1986!!!
I will check if an online version exists, however.......

Your claim indicates that electrical water heating
is 98% - 100% efficient, however it cannot and
will never be 100% efficient. To claim otherwise
one would need to re-write the laws of physics!

Sure in a Lab, one could engineer a high efficiency,
but we live in the real world........the energy is
converted using the "resistance" of the conductor
to provide heat energy, for example:

Losses include:

- energy lost in the cabling (Ohms Law)
- energy lost in the control circuitry (Ohms Law)
- energy lost in the element (high resistance)
- Standing losses
- even the neon indicator lamp uses a few milliwatts!

Malcolm wrote:
> Again you have ignored the power station inefficiencies.  Electric heaters
> are roughly 30% eff. from conversion of fuel to electricity and are
> therefore far worse than any of your direct fueled heaters, which
themselves
> could be seriously improved with a higher insulation requirement.
> Malcolm.

hear, hear.....

Of course, Carmine was referring to a "local" efficiency,
Malcolm is correct, at the best plants in the world the overall
energy conversation efficiency is at best only 36%, mainly
due the primer mover loss and transmission losses.

Electric water heating is convenient to the home user,
but the overall efficiency is very, very low indeed.

Regards,
John Herbert


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• Follow-Ups:
  • [GBlist] 100% efficient electric heat?
    • From: RET John <retjohnd@home.com>

• References:
  • RE: [GBlist] Zero Energy House on Washington Mall (fwd)
    • From: "Constructive Individuals" <constructive@cwcom.net>
  • Re: [GBlist] Zero Energy House on Washington Mall (fwd)
    • From: "Del Deletetsky" <rpdeletetsky@ucdavis.edu>
  • Re: [GBlist] Zero Energy House on Washington Mall (fwd)
    • From: "Dr. Carmine F. Vasile" <gfx-ch@email.msn.com>
  • Re: [GBlist] Zero Energy House on Washington Mall (fwd)
    • From: "John Herbert" <john.herbert@kelcroft.com>
  • Re: [GBlist] Zero Energy House on Washington Mall (fwd)
    • From: "Dr. Carmine F. Vasile" <gfx-ch@email.msn.com>
  • Re: [GBlist] Zero Energy House on Washington Mall (fwd)
    • From: "malcolm.scott" <malcolm.scott@ntlworld.com>