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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.<div>Happy Holiidays</div><div>Carmine</div><div>gfxtechnology.com <br><br><div><div id="SkyDrivePlaceholder"></div><hr id="stopSpelling">Date: Mon, 19 Dec 2011 20:01:43 -0500<br>From: jfstraube@gmail.com<br>To: greenbuilding@lists.bioenergylists.org<br>Subject: Re: [Greenbuilding] Triac Thermostats<br><br>
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Modulating electric heaters WONT save money if you discount the
unproven (and unlikely in my opinion) comfort savings. Exact same
energy will be delivered.<br>
All that changes with any strategy is temperature stability.<br>
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.<br>
<br>
I sure would not recommend these for most space heating
applications. For special applications, they are neat.<br>
<br>
Dr John Straube, P.Eng.<br>
<a class="ecxmoz-txt-link-abbreviated" href="http://www.BuildingScience.com" target="_blank">www.BuildingScience.com</a><br>
<br>
<br>
On 11-12-19 6:13 PM, Corwyn wrote:<br>
<span style="white-space:pre">> On 12/19/2011 5:32 PM, John
Straube wrote:<br>
>> You cant use a normal on-off thermostat with a modulating
control. <br>
>> The simplest thermostat for use with an SCR or TRIAC
would have<br>
>> what is called proportional control. For example, if the<br>
>> temperature fell below 68F by 0.1 F, 100W would be
delivered to the<br>
>> heater, of the temperature dropped to 67.8F, 200W would
be provided<br>
>> and if it dropped to 67F, 1000W would be delivered.
Because a<br>
>> smaller amount of heat is added with small temperature
drops, the<br>
>> temperature does not oscilate as much as an on-off
control with a<br>
>> 3F deadband as described in the example.<br>
> <br>
> But, it isn't, in fact, delivering 100W to the heater. It is<br>
> delivering 1000W to the heater for 1 second out of 10. Or
perhaps<br>
> 0.1 seconds out of 1 second. I guess that is the point I am
trying<br>
> to make.<br>
> <br>
> Since I have trouble believing that anyone *needs* within
0.1F<br>
> stability in their house temperature; a thermostat upgrade
will get<br>
> most of the accuracy improvement anyway; and since no one has
shown<br>
> energy savings, I would recommend these only if the lifecycle<br>
> benefits make them cheaper.<br>
> <br>
> <br>
> Thank You Kindly,<br>
> <br>
> Corwyn<br>
> </span><br>
<br>
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