[Greenbuilding] Triac Thermostats

Carmine Vasile gfx-ch at msn.com
Fri Dec 23 11:29:14 PST 2011

John: The physics you have "seen" relates to conversion efficiency -- not site energy use or annual operating efficiency, which is difficult to calculate because it includes cycling losses, heat distribution losses, stack losses, etc.       For example, from May of 1994 to May of 1995 (the last year we used an oil-fired, tankless-coil space & water heater) we used  37,232 kWh of site-energy; electricity + 700 gallons of home heating oil worth about $2800 today. We had a with a DHR system; no natural gas or propane.       The year after replacing the 20-year old oil system with a triac-controlled, tankless water heater we consumed 
22,762 kWh.      Site energy savings was 14,470 kWh (49.3 million Btu).      Site-air pollution was eliminated.      With today's global warming, a 20,000 kWh Solar PV system or windmill would reduce out site energy costs to zero, with no power plant pollution.
Happy HolidaysDr. Carmine F. Vasile, Ph.D. Electrophysicsgfxtechnology.com  

Subject: Re: [Greenbuilding] Triac Thermostats
To: gfx-ch at msn.com; greenbuilding at lists.bioenergylists.org
From: jfstraube at gmail.com
Date: Thu, 22 Dec 2011 00:48:31 +0000

As far as any physics I have seen, electric resistance water heaters and baseboards are both 100% efficient. Modulating the output does nothing to improve the efficiency. 
The efficiency of the grid is around 30%, so electric resistance heat is around 30% efficient. 
Use a heat pump at COP of 3 and you are now around 90% efficient.  

I won't comment on oil heat since this is a small and rapidly shrinking form of heat. 
Sent wirelessly from my BlackBerry device on the Bell network.From:  Carmine Vasile <gfx-ch at msn.com>
Date: Wed, 21 Dec 2011 18:27:24 -0500To: <jfstraube at gmail.com>; GB Forum<greenbuilding at lists.bioenergylists.org>Subject: RE: [Greenbuilding] Triac Thermostats

John: You are referring to electric resistance heating not electric hot-water heating, which can be twice as efficient, cheaper than oil, and far more comfortable.  "Exact same energy" will not be delivered because resistance baseboard heating is far more wasteful. I've  used both.Happy HoliidaysCarminegfxtechnology.com 

Date: Mon, 19 Dec 2011 20:01:43 -0500
From: jfstraube at gmail.com
To: greenbuilding at lists.bioenergylists.org
Subject: Re: [Greenbuilding] Triac Thermostats


    Modulating electric heaters WONT save money if you discount the
    unproven (and unlikely in my opinion) comfort savings.  Exact same
    energy will be delivered.

    All that changes with any strategy is temperature stability.

    It is quite easy to buy a new electronic thermostat for baseboards
    that control +/-0.5.  The built-in thermostat that often come with
    baseboards often are +/-1.5F.


    I sure would not recommend these for most space heating
    applications.  For special applications,  they are neat.


    Dr John Straube, P.Eng.




-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/greenbuilding_lists.bioenergylists.org/attachments/20111223/53970134/attachment.html>

More information about the Greenbuilding mailing list