New gas furnace/AC recommendations?

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On Sun, 12 Dec 2010 10:35:33 -0600, " snipped-for-privacy@att.bizzzzzzzzzzzz"

GENERALLY used in a series configuration because it is more efficient that way.
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On Sun, 12 Dec 2010 16:30:58 -0500, snipped-for-privacy@snyder.on.ca wrote:

Switching shunt regulators are exceedingly rare because the gain generally isn't worth the cost. Another topology almost always wins.
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On 12/12/2010 6:29 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

I came across a ferroresonant transformer power supply in a piece of gear a friend had and he was mystified by the darn thing and why it wasn't working. I obtained a replacement oil filled capacitor from an electric motor rewind shop and got the equipment working again. He had worked with all manner of DC voltage regulators but had never seen an AC voltage regulator. I guess it helps to broaden your horizons in a search for knowledge. :-)
TDD
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On Sun, 12 Dec 2010 19:08:26 -0600, The Daring Dufas

They also are not often used anymore because it's cheaper to use a switcher of some sort. Iron is expensive. Silicon is cheap.
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On 12/12/2010 7:52 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

I have a notion that the constant voltage transformer is a lot less susceptible to voltage spikes and lightening strikes than a switcher. I've installed a lot of them to protect phone systems power supplies. The things work well as AC line filters and isolators.
TDD
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On Sun, 12 Dec 2010 19:52:10 -0600, " snipped-for-privacy@att.bizzzzzzzzzzzz"

required - and MUCH cheaper than silicon.
It's just you need so much LESS silicon to do the job - and less iron and copper when the frequency is in the khz or mhz range.
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On Sun, 12 Dec 2010 23:08:49 -0500, snipped-for-privacy@snyder.on.ca wrote:

Which, of course, is a *silly* argument.

Ran across one lately that runs at 180MHz so the (isolation) transformer could be integrated on the chip.
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On Sun, 12 Dec 2010 18:29:50 -0600, " snipped-for-privacy@att.bizzzzzzzzzzzz"

brushless "alternators" on small engines and some motorcycles.
With per-mag "alternators" or "dynamos" the output cannot be controlled, so shunt regulators are used. Linear shunt regulators have proven rather short-lived in some apps, so the higher-end units have gone to switch-mode regs.
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That is amperage draw not power consumption.
The GE ECM units don't have any PFC so they have the same roughly .6 power factor as any old computer power supply that just has a diode bridge and capacitor at the input. That 6.3x120x.6 is roughly 454 watts. Since 1hp is 746 watts that puts the efficiency at about 82%
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wrote:

The equipment I install, already has ECM motors in it. the stuff with ECM motors in it has a 10 year parts warranty, and the heat pumps have either a 5 year or 10 year unit replacement warranty.
I don't know why I would install an air handler with a PSC motor in it when there is only a small difference in price for the ECM, and the PSC only has a 5 year parts warranty, period.
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I'd say it's ignorant to assume everyone that's looking at a new HVAC system lives in the same climate that you do. I'm in coastal NJ and the existing 26 year old system handles the humidity just fine. If it's hot enough to be running frequently, no humidity problem. If it;s one of those few days where it's not hot enough to be running and it's getting humid inside, I lower the thermostat one degree and in 30-45 minutes, you can feel the humidity has decreased and it's comfortable. And that's with an inefficient system with a single speed blower.

My utility bills are gonna drop too when I swap out that 26 year old system and go to a high efficiency system with a PSC blower.

That part I agree with. But there is no need to take out an ECM motor. You just buy a high efficiency system that doesn't have one in it.
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I'd say it's ignorant to assume everyone that's looking at a new HVAC system lives in the same climate that you do. I'm in coastal NJ and the existing 26 year old system handles the humidity just fine. If it's hot enough to be running frequently, no humidity problem. If it;s one of those few days where it's not hot enough to be running and it's getting humid inside, I lower the thermostat one degree and in 30-45 minutes, you can feel the humidity has decreased and it's comfortable. And that's with an inefficient system with a single speed blower.

My utility bills are gonna drop too when I swap out that 26 year old system and go to a high efficiency system with a PSC blower.
--------------------------------------------- All of the high efficiency have ECM blower motors, the only ones that have PSC blower motors are the basic, low end, 13 SEER systems..... that would be the "spec house", and landlord specials.

That part I agree with. But there is no need to take out an ECM motor. You just buy a high efficiency system that doesn't have one in it.
You cannot get a "high" efficiency system without an ECM motor in it. Only the basic, entry level 13 SEER systems have PSC motors in them.
FWIW, the latest technologies in residential heating and cooling systems are using serial controlled, Variable Frequency inverter drives that literally vary the systems output from 40% to 115% of its rated capacity depending on demand. Even the compressor is variable speed..... This is where residential heating cooling systems are headed. Your not going to have a choice in refrigerants for air conditioning either.
These changes have been in the works for over 20 years.... I just gotta wonder why a select few are bitching about it now.
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What kind of motor do you think is in virtually every electric or hybrid vehicle, and the majority of electric cycles??? ECMs are a lot less trouble prone than brushed DC motors. ONE moving part, no open commutation, no wear, no sparks, no brushes.

Still has enough of an advantage that I wouls choose the ECM over the PCM even if I did not choose to run the fan on low constantly.
Hey, it's your choice. I feel I made an informed choice, and I'm more than happy with the choice I made. You want to run with 1930's technology, that's fine with me. I won't twist your arm. But I also will not agree that the old stuff is always better

That's fine as long as your old furnace lasts. I wouldn't go out and spend $2000 (or more) for a new furnace just to get an ECM fan. But I sure wouldn't cheap out and buy a furnace with a PSC fan motor when the time comes to change the furnace
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You keep omitting the most important reason for getting one, comfort. It will in low speed remove near 50% more moisture. You can at low speed run it to dehumidify with out cooling much. Great on those 70f days when its 75 inside and real humid. it can be run by Humidistat, just what alot of areas near water need often. Or to even out heat or Ac in a poorly ducted house. You dont like them so dont buy one.
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ransley wrote:

Gee, I wonder what that liquid is that runs out of a pipe coming from my A frame above my furnace and into the floor drain beside my furnace. ?
Ever see a dehumidifier that doesn't get enough air-flow? See how much frost accumulates on it? See how that frost doesn't melt and turn into flowing water until you turn the unit off?
An evaporator coil that doesn't get cold enough to sweat when your blower fan is running full speed means that you're AC unit is too small capacity or has lost freon.
And you don't want it to get so cold that you start a frost build-up either.
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On Dec 9, 8:17pm, snipped-for-privacy@snyder.on.ca wrote:

I have 57 years of service experience with conventional blower motors that cycle on and off with the furnace/AC and have not had one fail yet. So, I'd say using them only during heat or AC vs running them 24/7 is a non- issue in terms of longevity.
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I have 57 years of service experience with conventional blower motors that cycle on and off with the furnace/AC and have not had one fail yet. So, I'd say using them only during heat or AC vs running them 24/7 is a non- issue in terms of longevity.
--------------------------------------------------- Running the blower on continuous for A/C here in the deep south will actually raise the indoor humidity, but during the winter I do ust the "circ" function on the system control to keep the temperature mor even between the 3 floors. The "circ" function brings on the blower for 15 - 20 minutes an hour, just to circulate the air in the house.
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wrote:

I thought furnaces were rated on BTU *output*, not input. The input is mentioned to calculate the efficiency.
Am I right?

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The ones I've looked at are rated as BTU input, primarily because they have a fixed operating point (orifice sizes, pressures, etc.) and the efficiency isn't well regulated. The burner efficiency can be measured and the BTU output calculated, though.
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On Mon, 06 Dec 2010 19:49:24 -0600, " snipped-for-privacy@att.bizzzzzzzzzzzz"

Interesting. So do they have an AFUE rating?

But the burner "efficiency isn't well regulated". So you mean an instantaneous measurement of efficiency?
Or an average measurement? Isn't an average measurement made only by looking at heat (BTU) output and dividing it into BTU input?
How can burner efficiency be measured without first measuring BTU output? What is there about the burner that can be measured other than BTU output?
It's not like a lever where the lengths of on both sides of the pivot can be measured, or a gear where the number of teeth can be counted, etc.** In cases like this, efficiency is not a real thing that can be measured. Only input and output can be measured.
**Even in the case of levers and gears, measuring theoretical efficiency by measuring arm length or counting teeth assumes there is no loss due to friction or slipping. The real efficiency of a mechancical device can only be determined by measuring input and output and dividing one into the other.
The spec sheet I got for at least one oil furnace this year included input and output and AFUE. If it was on the web and I can find it, I'll post it.
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