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From: John De Armond
Subject: Re: HUGE electricity increase - help!
Date: Sun, 26 Mar 2006 04:29:55 -0500
Message-ID: <>

On Tue, 21 Mar 2006 15:38:24 -0500, "Kremlar" <>

>Of course I do want to lower my power usage, but I want to do so in a way
>that won't affect me in a negative way, at least not too much.
>For example, I sometimes have to run down to my office, check my email very
>quickly and rush to an appointment.  I don't want to turn my PC completely
>off at night and have to run down, boot the PC up, log in, go into my email,
>download any new email, etc...  But, if there's a way I can reliably put the
>PC into a sleep mode, quickly wake it up and download my email almost as
>fast as before, I'll do it.

You've gotten some good advice so far and now I want to add some more.
Claimer: I'm a retired engineer who spent most of his career in the
utility biz.  One of my "fun businesses" is energy auditing.  I've
developed some productive techniques using inexpensive equipment that
is very effective.

First off, about that bill.  I don't yet have enough information to
know for sure but I'm betting on a combination of catching up on
estimated readings, an energy-inefficient house, cold weather and high
winds and that exposed hot tub.  With the top off that hot tub and the
weather very cold and windy, the heater was probably on all the time.
If you'll tell me the power rating of that heater we can figure it

From reading between the lines, it sounds like you bought a cheap-sh*t
spec house designed primarily to make the developer money at the
expense of high operating costs.  These spec houses sell on glitz to
buyers who don't know what to look for.  Don't feel bad - The first
house I bought at the wise old age of 21 didn't have a speck of
insulation in it.  None.

So now you have the house so you have to figure out how to live with
it.  The thing you do NOT want to do is to assault the problem
willy-nilly without first determining where the problems are.  You'll
end up spending lots of time and money for relatively small results
and you might even make things worse.

The first thing to do is to assess the current situation.  You need to
determine all the consumption centers in the house.  That means
metering all significant loads for a long enough period to get a good
average.  For things like your computers that you use all the time, a
day or two is long enough.  For things that are not used all the time
or maybe even not every day, you'll need to measure for a week or
more.  A washer or dryer, for example.

The Kill-a-Watt gadget that everyone is recommending is a nice little
instrument that does many things accurately and cheaply.  I have a
bunch of 'em.  But it has one major weakness for long term auditing
(more than a day).  Volatile memory.  If there is a power drop or
glitch, even for a second, the accumulated watt-hours and run-time are
lost.  There are slightly more expensive instruments, for example, the
Watts Up line, that have battery backup.

Other limitations include the ability to measure only loads that plug
in and only 120 volt loads.

A more suitable instrument, both from a cost and an accuracy
standpoint is the common old electromechanical watt-hour meter like
your power company uses.  The good old "power meter" has several nice

* totally non-volatile, as the reading is held in a mechanical
* Very accurate.  At least 0.25% and usually better than 0.1%.
* can be used on both 120 and 240 volt loads.
* very cheap.

I have dozens of power metering modules like this:

Used power meters are available for as little as $5-10.  Never more
than $25.  I use the meter bases because they're safe and look
professional but you can bolt the wires directly to the "stabs" on the
meter.  Used meter bases are easy to come by if you look around.  Flea
markets, home remodels, those kinds of places.

I have these set up for both 120 and 240 volts with a variety of plugs
and sockets and some with alligator clips.  The later are useful for
metering things like a water heater or that hot tub.

Use is easy.  Hook it up.  Using a grease pencil or Sharpie, write on
the front of the meter the time, date and starting reading.  Let the
meter run long enough to accumulate at least 100 watt-hours,
preferably at least 500, then write down the stop time, date and
ending reading.  Subtract the beginning reading from the ending
reading to get the KWH (kilowatt-hours) used.  Divide that by the time
interval in hours to get the average watts.  I have a nice spreadsheet
that automates all this recordkeeping.  Drop me a note if you'd like a

What you need to do is meter every significant load in the house.  By
significant, I mean any load that runs a significant part of the
month, say, the refrigerator and the furnace and any high draw load
such as a dryer or water heater.  You can ignore small low use loads
such as those CF lamps and even very low use high draw loads such as
the microwave.

You'll want to normalize all the consumption figures to the same
interval.  I use KWH per day.  Once you do that you can compute the
percentage of the total each load represents.  Finally you can
estimate the cost of reducing the consumption of each load and the ROI
in terms of dollars per KWH per day saved.  I also compute cost per
month to operate since that puts it in terms of actual dollars.  Once
you have those numbers, it is obvious where to start - with the
biggest bang for the buck.

If I'm right in my guess about your house being a cheaply built spec
house, I think you'll find that the furnace, the AC, the water heater
and that friggin' hot tub will represent the highest cost items.

While you're doing all this testing, be sure to check the insulation
in the walls and ceiling.  I bet that the house has just the minimum
necessary to meet codes.  Insulating the ceilings is one of the most
cost-effective things you can do, along with ferreting out air
infiltration routes such as around outlets and baseboards.

That electric water heater, no doubt the lowest end contractor model,
is probably one of the bigger users.  Think of it as being fueled by
burning dollars :-)  If your hot water usage occurs mostly at one or
two times a day - everyone takes baths in the AM or PM for instance -
you'll save a LOT of money with an on-demand heater fueled by either
gas or oil.  I'm very fond of the Paloma brand of gas fired on-demand
heater and have them in all my properties.  It is simple, non-electric
and incorporates a proportional gas valve so that the water
temperature remains the same regardless of water flow.  The competing
brands generally contain electronic controls which are more prone to
damage from lightning and such and of course, they don't work when the
power is off for whatever reason.

If this is a large house where you don't use all the rooms all the
time then you might want to look at zoning the air system.  This
involves installing motorized dampers in the ducts feeding each room,
along with individual room thermostats.  You can get fancy with home
automation stuff that runs a program to have certain rooms comfortable
at certain times but for the most part, a simple thermostat in each
room will suffice.

This is an inexpensive mod, particularly if you do most of the work
yourself.  Usually no more than $100 per room.  If you zone off much
of the house at once then you'll probably need a dual rate oil burner
to prevent overheating the heat exchange.  This is a burner that can
fire at two different BTU rates.

I kinda doubt that the sewer pump is contributing to much of the
demand unless the switch is stuck or there is water infiltration.
Metering it will quickly show that.

Your computer farm may or may not constitute much of a load - you'll
have to measure to find out.  My Linux server with 1.2TB across 5
spindles, all set to time out after a short time, only draws about 30
watts when idle.  That's not worth worrying about.  OTOH, the old 19"
CRT that I use with it draws more than 300 watts.  That's why it sits
with the power off most of the time.

At your current level of usage you don't need to worry about the small
things the off-gridders worry about, things like phantom loads from
wall warts and the like.  Unless you light up the house all the time,
even the CF conversion isn't going to make all that much difference.
Address the big things first.

One other thing you can investigate is heating only your bedrooms
using plug-in electric heaters at night with the house thermostat set
to something like 50 deg.  A programmable 'stat to bring the house up
to the comfort level before the alarm goes off is very nice.

You'll have to meter the furnace to see if this makes a big
difference.  If you have a lot of thermal mass in your house and/or
the furnace is on the small side, having to run most of the night to
keep up then turning it off at night won't be productive, as it won't
be capable of bringing the house back up fast enough in the AM.  OTOH,
if the furnace is large enough to go from 50 to 72 in, say, an hour,
then setting it back and space-heating the bedrooms will be very

You can do the same thing in the summer using one or two of those
self-contained portable air conditioners that vent through a hose in a
window.  They're becoming quite popular and for a good reason.
Spot-cooling just the occupied areas can save a lot of money.  I like
my bedroom to be in the low 60s so I use one of those to blow cold air
across my bed.  The AC is off in the rest of the place at night.  At a
cost of from $300-600 depending on BTU capacity, this portable AC can
pay for itself in a single season.

You might check with your utility to see if it offers a free energy
audit.  Most do.  They won't do the kind of stuff I've discussed but
they will do things like checking your insulation, your windows, air
infiltration and so on.  Even if you have to pay a little for it, it's
well worth the money.

>The hot tub is a sore spot.  I love it, and enjoy using it when I'm in it,
>but it's tough to justify the cost based on the amount that it's used.
>Before I hooked it up at our new house, I had my fiance swear up and down
>that she would use it.  It's barely been used so far.  I don't want to give
>it up, but I need to find a way to keep it but reduce the energy cost as
>much as possible.

Ah, that hot tub.  A hole in the patio that you toss money into :-)  I
agree that it doesn't make sense to keep that thing hot if you're
never using it.  there are a couple of options.

If you truly seldom use it, say, once or twice a month, then it would
make sense to dump the water after each use and fill it with hot water
the next time you use it.  Here is where an on-demand water heater
comes in.  It can heat all the water you need in real time.  My 5GPM
Paloma heater could fill a 500 gal tub in 100 minutes.  Actually
faster than that because it can do 5GPM to a 100 deg rise.  To fill
the tub you'd want to dilute its output with cold water, as you'd not
last long in 140-180 deg water :-)

The cost of the water and the fuel to heat it with will be much less
than the cost of keeping it hot plus the cost of chemicals plus the
labor to monitor the water chemistry.  Of course, you'd need to
compute this using your actual fuel and water costs.

If you use it enough that dumping and filling becomes impractical then
you can look at a "blast heater", a fueled heater with enough BTU
input to bring the water from approx ambient to soaking temperature in
an acceptable time.  A pool heater with a half million or more BTU
input, either gas or oil or even wood, would do the job.  When you're
not using the tub, the pump could be off and the tub kept from
freezing by a small immersed heater such as is used to keep livestock
water troughs from freezing.

>I don't want to ditch my whole-house audio system, or my home theater -
>those are things that I enjoy and am willing to pay for.  If there's
>anything I can do to reduce their energy use, I'm all for it - as long as it
>doesn't affect my enjoyment too much.

Unless you're a 24 hour toob junkie, that entertainment stuff is
peanuts compared to your real problems.

One more thing.  If you live in an area where weather-related power
outages are common, considering how reliant you are on electricity,
you might consider getting a standby generator.  Things could get
rather, er, sh*tty rather quickly if that sewage pump goes without
power for very long. :-)

You can spend an unbelievable amount of money on a system but you can
also do it quite affordably.  I'm quite fond of those Generac Guardian
systems that Home Depot, Northern Tool and the like sell.

The real money is with the automatic changeover systems that
automatically start the generator and transfer the loads when the
power fails.  Some automatic systems cost as much as the generator.

If you can live with a manual system where you push a button to start
the generator and flip a transfer switch when the power goes out then
you can do it quite affordably.  I noticed that Northern has a 100 amp
manual transfer switch on sale now for $100.

What you'd need to do is first identify all the critical loads - the
furnace, the sewage pump, some lighting, the refrigeration, perhaps an
outlet or two in the kitchen to run a hotplate or microwave.  You'd
move all those circuits to a separate sub-panel connected to the main
breaker panel though the manual transfer switch.  When the power
fails, you crank the generator, then flip that switch and all your
critical loads get power.

One last thing.  The hecklers.  You know, those folks who live in one
room mud huts, shivering in the dark, reading Usenet by candle
light....  Just ignore 'em.  Consider them the mosquitoes of the
Internet. :-)


From: John De Armond
Subject: Re: HUGE electricity increase - help!
Date: Sun, 26 Mar 2006 18:12:31 -0500
Message-ID: <>

On Sun, 26 Mar 2006 17:03:07 GMT, CJT <> wrote:

<snippity - please don't quote 500 lines of text for your one-liner!>

>And, if you're using a 240 V meter on 120 Volts, as it would seem
>from the pictures, divide by two.  :-)

Nope.  If you look closely you'll notice that I run the current
through the meter twice, once coming through the hot leg and once
going out through the neutral.  That provides twice the current signal
to compensate for half the potential.  The register reads correctly.
I've checked it on my meter calibration bench against my watt-hour
calibration standard just to make sure theory matches practice. It

This does NOT work with electric meters, as the electronics power
supply depends on there being 240 volts.  Yet another reason to stay
away from the electronic ones.

From: John De Armond
Subject: Re: meter disc revolution
Date: Tue, 04 Apr 2006 02:26:03 -0400
Message-ID: <>

On Mon, 3 Apr 2006 21:54:17 -0400, "Solar Flare"
<sfart@hottomale.invalid> wrote:

>GE electronic types (CL200 he told us) is marked "Kt" and not "Kh"
>Kh was only used for mechanical disk meters.

You just keep posting and posting about stuff for which you know

The CL200 spec means that the meter is a "200 amp class" unit.  In
other words, the current legs are rated for 200 amps.  It has nothing
at all to do with whether the meter is electronic or not.

Further, I can assure you that both electronic and mechanical meters
have a Kh factor.  I'm looking at one of my meters right now, a
Landis+Gyr Model SSM-2 three phase meter.  The Kh specification on the
face is 1.8. There is no wheel to count but OTOH, the display
resolution is sufficient to read short term changes directly.

Kt refers to the "true K" value of the output pulse of a transmitting
meter and represents the true value of the pulse, normally Kh/12.  Kt
has no meaning for a self-contained non-transmitting meter.

I can tell by your handle, "sFart" that you have little self-respect
and thus you probably don't mind making such egregious errors.  In the
unlikely event that I'm wrong, I strongly recommend you avail yourself
of some of the excellent metering docs at the Landis+Gyr and the GE
metering websites.  If you care to actually know anything about
metering, I suggest "The Metering Handbook" from  You could actually learn something by
prowling that site.


From: John De Armond
Subject: Re: meter disc revolution
Date: Tue, 04 Apr 2006 17:13:05 -0400
Message-ID: <>

On Tue, 04 Apr 2006 20:45:05 GMT, "daestrom"
<> wrote:

>"Solar Flare" <sfart@hottomale.invalid> wrote in message
>> NO.
>> GE electronic types (CL200 he told us) is marked "Kt" and not "Kh"
>> Kh was only used for mechanical disk meters.
>The OP *quite clearly* asked about, "...So I figured I'd turn them on and
>off and make calculations using the speed of the meter disc, the thing with
>the little black wedge painted on it."
>Do you know of an electronic meter that has a 'meter disc'??  With a 'black
>wedge painted on it'??

Sure.  That's called a hybrid meter.  The induction meter movement is
still more accurate and more rugged than available electronic
transducers so the meter uses the wheel strictly as an encoder.

I have several of these and could, I suppose, go out to the shop and
get some part numbers.  But it would be just as easy for you to go to
the Landis+Gyr or GE web site and look them up yourself.  Unless you
want to pay retail (up to $100 for a single piece), what you care
about is what is available used/surplus or whatever.

There aren't many user benefits to a hybrid meter.  The meter CAN
display usage rate (watts), peak usage (peak watts), demand (peak
watts over the specified interval, usually 15 minutes)  in addition to
energy consumption (watt-hours) but it can't display VARs, PF or other
things that a pure electronic meter can.

I personally prefer the purely mechanical meter for energy surveys
because no power failure can cause the reading to be lost.  Hybrid
meters have backup batteries but as Murphy says, just when you need it
the most, that battery fails.  Lightning can also scramble the
electronic register's brains.

>As someone else pointed out, CL200 is the meter class, not necessarily the

That was me.  I repeat my advice that I gave in that post.  Go to the
applicable web sites (especially GE) and read up on metering using
their huge library of technical documents.

One more comment.  I didn't feel comfortable about how the Kt thing
was left.  I hit my books and manuals.  I can find it used only once
in a Landis+Gyr transmitting meter manual.  It does not seem to be a
standard term.

There is another constant, the Km constant, that is applied to
electronic meters.   This refers to the number of watt-hours measured
during each sampling interval.  It is the electronic equivalent of a
wheel revolution.  In fact, everywhere I've been involved in metering,
Kh and Km have been used interchangeably.


From: John De Armond
Subject: Re: Home Electric Consumption
Date: Mon, 01 Oct 2007 17:48:26 -0400
Message-ID: <>

On Mon, 01 Oct 2007 12:59:31 -0700, bscallywag <> wrote:

>My house consumes a staggering 112kWh a day ( according to my meter )
>My hot water system uses 31kWh a day
>My Cooling system uses about 30Kwh a day
>My well and water processing uses 4kWH a day
>Lights use 5kWh a day
>Everything else - Fridges (2), Freezer, TVs, Computers and cooking use
>about 10kWh
>That makes 80kWh a day.
>So where is the rest of the power going?
>Is it possible that my electricity meter is that far off?

Unlikely, with one exception.  Easy enough to check.  Open all breakers and apply a
single known load (a 500 watt halogen lamp is a good choice.  So is a 100 watt lamp.)
and count the disk turns.  Compute the indicated watts using the meter's Kh factor
and the time interval.

Based on both industry data and my own experience with a utility engineering
background, meters either work or they don't.  Calibration is very stable.  The one
exception is if the drag magnet becomes demagnetized.  The drag magnet sets the speed
slope of the disk.  That is, how fast the disk turns for a given load.  The magnets
are very stable but certain external forces can demagnetize them.  The most usual is
a VERY close lightning strike.  This is an extremely rare occurrence, though, and can
be easily checked with the above procedure.

How are you measuring the various loads?  Some of those figures seem quite high.
Particularly the water heater and well pump.  Just to get a better feel, I converted
the well pump into horsepower-hours - 5.4 approx.  If your pump is a 1 hp unit then
it would have to run over 5 hours a day to consume that much energy, neglecting
losses, of course.  Do you run the water that much and/or could you have a leak?

The lighting load also seems quite high.  Is this a large house?  Outdoor decorative
lighting, maybe?  Also, I don't see any mention of a washer or dryer.

I'd like to know some more details.  How large the house is, how many occupants, how
you arrived at the figures, is the electric meter mechanical or electronic, etc.  30
kWh a day can't just disappear so there's a problem somewhere.

You might also state what instruments you have at your disposal.


From: John De Armond
Subject: Re: Home Electric Consumption
Date: Tue, 02 Oct 2007 20:09:10 -0400
Message-ID: <>

On Tue, 02 Oct 2007 15:19:32 -0700, bscallywag <> wrote:

>> I'd like to know some more details.  How large the house is, how many occupants, how
>> you arrived at the figures, is the electric meter mechanical or electronic, etc.  30
>> kWh a day can't just disappear so there's a problem somewhere.
>The house is 6000sq ft - 2500 basement, 3000 main level, 500 top
>floor. 4 people (2+2 small)
>The meter is electronic.
>I have - calibrate - hand meter, mostly fluke ( 2% accuracy ).  A Rode
>and Schwarts power meter that will deal with 220v split phase that I
>can borrow on the weekend.
>I also have a kilowatt meter and a clamp on wire power meter
>( borrowed ) that is intended for monitoring home office etc usage.
>The water usage is high because yes we did have a leak,  the poly. had
>come off of the pit-less coupling.  That is now fixed,  but all my
>data runs previous to that fix.
>Measurement...  I have hour meters installed on the electric hot tank
>elements, well, and HVAC compressor and ODU fan.
>Measurement for them is hours x power (kw)
>Cooking is on propane.
>Cloth washing is cold water only, with air drying ( we don't own a
>tumble dryer ).  And is lumped in in the other category.

My first advice would be to call your utility and ask them to check your meter's
calibration.  Be sure to tell them that you've suffered a nearby lightning hit.  The
usual procedure is for a meter man to come out and swap out meters, then take the old
one back to the meter shop for a calibration check.

If your meter were mechanical then I'd doubt there being any problem.  With the
electronic versions, I'm not so sure.  One of my utility clients is having a very bad
experience with their new fleet of electronic self-reading meters.  Lots and lots of
outright failures and LOTs of PO'd customers with suddenly huge power bills.  Many of
those revenue issues are the result of defective meters.

For a house that large I don't think your total usage is all that far out of line,
assuming you HVAC the whole place.  Your consumption can certainly be reduced but
it's going to take some work.

Back to your energy auditing. I see a whole bunch of problems here.  Let's walk
through 'em.

The first and probably the most serious problem is lack of uniform metrology and
methods.  You have several instruments of unknown accuracy and calibration status and
you're using a disparate collection of measurement techniques, some of which just
won't work.

The first thing to do is constrain error accumulation.  The use of several
instruments with various characteristics and (presumably) without NIST-traceable
calibrations means that you have no control over error which I suspect is large.
Worse, since you must add the results of many measurements to compare with the
cumulative (revenue meter), you have totally uncharacterized and controlled error

The simplest and least expensive but most tedious method is to use only one
instrument of known accuracy.  Errors will still add up but if the instrument is
sufficiently accurate (1% FS is good, 0.25% is great) then the error accumulation
won't be too bad.

A second option, the one I use in my energy auditing, is to use multiple identical
instruments, calibrated against a single lab transfer standard.  My lab standard is a
GE 0.1% class watt-hour transfer standard.  I have this instrument NIST-traceable
calibrated occasionally but since I have a 20+ year history on the instrument, I know
that barring physical damage, its calibration is stable and accurate.

I calibrate each instrument before an audit and then check it afterward.  This
precludes any damage, drift or other problems causing bad data to creep into my
results.  If there is a significant change then I redo that measurement.

You MUST measure actual accumulated watt-hours on each load.  Your hour meter
technique simply won't work because the load simply isn't stable enough over a long
period of time.  Even with the water heater where the resistance is stable, hourly
and daily voltage fluctuations invalidate a simple "elapsed time and single wattage
reading" method.  With loads such as the AC, the actual power draw varies widely
according to the point in the operating cycle, ambient conditions and other factors.

You can't do volts * amps because that doesn't take into account power factor.  As
the power factor varies with load on electric motors, for things like washing
machines and AC compressors, it's difficult to impossible to characterize "a" power

The easiest, simplest and cheapest method of making these measurements is with the
common revenue watt-hour meter.  Mechanical revenue meters are quite accurate
(usually better than 1%) and are extremely stable.  The turndown ratio (ratio of
maximum to minimum measurement capability) is second only to the very most expensive
test instruments.  Used watt-hour meters are widely available on the net for under
$30, frequently less than half that.

Here's my little stub of a web page on how I use revenue meters

I have in excess of 50 of these setups in my meter fleet.  Though I show a large 200
amp meter base in those photographs, I prefer the 100 amp or "CT" meter base that is
round and of the same diameter as the meter.  Lighter and easier to handle.

A meter base isn't strictly necessary.  Several of my early setups consisted of
nothing more than a thin plywood inverted "T" with slots cut in the vertical piece to
match the meter stabs (terminals).  The stabs have holes through which I passed bolts
and nuts to which the wiring was anchored.  If the wood is varnished it is a good
dielectric even when moist.  The only real requirement is that the meter remain
nearly vertical.

I have a few of my meters set up with alligator clips and/or flying leads so that I
can meter at the breaker panel.  I simply lift the hot and neutral wires (or hots for
240 volts) of the branch being investigated and place the meter in series.

What you'd need to do is to get one or more of these meters and methodically measure
each load in your house.  You can use the spreadsheet on my site to keep track of the

If that clamp-on meter you have is a true-RMS responding true watt meter (voltage AND
current inputs) then you can do a quickie check of your revenue meter.  The procedure
is to gain access to the incoming feed at a point where you can gather both legs
together.  I normally do that at the weatherhead.  Arrange the legs in a cross
pattern so that the current flow in each leg through the clamp meter is opposite the
other.  That is, the two add.  Attach the potential leads between the legs (240
volts).  The meter reading is divided by 2 to get the actual total wattage.  This
configuration is identical to the way the revenue meter does it and handles both 120
and 240 volt loads.

Of course, you must observe proper electrical safety while doing this.  I use
standard utility hot gloves when making this measurement.  If, for some reason, I
don't have my gloves handy, I layer on many layers of non-latex examination gloves.
Typically 6-8 layers, depending on the brand of glove and how stiff they are.  Over
those go leather work gloves to protect the insulating gloves from abrasion or

The service drop at the weatherhead is unfused other than the transformer primary
fuse so a fault can generate a few tens of thousands of amps of fault current.  Keep
that in mind.  I wear flame-proof (utility worker) pants and shirt and a face shield
when I'm messing with power drops.  My safety gear has never been tested but I've
seen the result of service drop shorts and it isn't pretty.

What you'll do is compare that meter's reading in watts to the revenue meter's watts
indication.  I outline how to determine watts with a mechanical meter on that web
page above.  An electronic meter is a bit different.  Normally it has an indicator,
either an LED or bars on the LCD display, that indicates watt-hours consumed.  The Kh
factor will tell you what each event is worth in watt-hours.  Typically with LCD
displays, the Kh is 1.  That is, each movement of the bargraph is one watt-hour.  LED
indicators can be anything.  I've seen Kh values as high as 8.  That is, 8 watt-hours
for each flash.

At the same time you observe the clamp-on meter to verify that the load is constant,
you count the events over a timed interval, multiply by the Kh factor and divide by
the time interval of the measurement to get average watts.  I like to accumulate at
least 25 events and preferably 100 to minimize quantization error. The two values
should agree to better than 1%.


From: John De Armond
Subject: Re: Gas Dryers
Date: Sun, 31 Aug 2008 12:17:55 -0400
Message-ID: <>

On Sun, 31 Aug 2008 00:25:20 -0700, Winston <> wrote:

>Malcolm "Mal" Reynolds wrote:
>> I have a gas dryer that takes maybe 40 minutes to dry an average load. On hot
>> days I just run it on's either taking hot air from the garage or
>> from inside the house. It takes a little longer than 90 minutes to dry a load
>> this way.
>> I'm wondering if someone can give me an idea of how efficient this is.
>I dunno but, (building on your idea) I'd be interested if anyone has used a
>solar air heater to substitute for gas consumption.

I dunno, but this looks like turd polishing to me.  Given the tiny cost
involved, there is no return on investment, at least not over a reasonable
time period.

I've measured my electric dryer.  It draws 2.2kW and takes 45 minutes to dry a
large load.  It's an old dryer, not one of the newer more efficient ones. That
2.2kW * 0.75hr = 1.65kWh.  At our current $0.08 per kWh power rate, that costs
13.2 cents a load.  I'm single and run from 2 to 4 loads a week.  Let's call
it 3.  That's $0.132 * 4weeks * 3loads = $1.58 a month.

I think that I have better things to do with my time than try to save a buck
and a half a month.  Even if you're paying some obscene power rate like in NYC
or CA, it still doesn't make sense.  Especially since it STILL costs money to
run the motor.


From: John De Armond
Subject: Re: Gas Dryers
Date: Sun, 31 Aug 2008 17:19:22 -0400
Message-ID: <>

On Sun, 31 Aug 2008 11:51:31 -0700, Winston <> wrote:

>Neon John wrote:
>> I think that I have better things to do with my time than try to save a buck
>> and a half a month.  Even if you're paying some obscene power rate like in NYC
>> or CA, it still doesn't make sense.  Especially since it STILL costs money to
>> run the motor.
>> John
>I see what you mean.
>Perhaps the biggest bang for the buck isn't in clothes drying.
>Even at the U$0.12 per kwhr I'm paying, the total equivalent bill
>would be under U$30.00 a year for me.
>I hear that 56% of my energy dollar goes to space heating.
>If I could cut that out of my energy bill, I could save ~U$628 a year.
>That's more like it!

You ought to do an energy audit on yourself.  It's hard to save energy until
you know where it's actually going.  Here's a fairly incomplete page on the

The energy audit spreadsheet makes keeping track of energy usage easy.  You'll
need either some meters like I show on my page or a few Kill-A-Watts.  KAWs
don't work on 240, unfortunately, so metering you biggest energy consumers
will require something like the revenue meter that I show or a clamp-on

For most folks, comfort and water heating are the two biggies.  A solar water
heater could pay for itself fairly rapidly, depending on how much sun you get.
When I lived down in the city here in E. TN, my homemade one was worth the
effort despite having weeks at a time of overcast.

THE biggest things I've done to reduce my energy consumption have been to
install a wood stove and zoning my AC.  Zoning means not heating or cooling
all of the house the same.  I have a strange metabolism and require a cold
environment to be comfortable.  In the low 60s to high 50s in my bedroom.

One method of zoning, even with a central unit, is to install a window unit or
mini-split in the bedroom or office or wherever you spend most of your time
and then set the main thermostat to some higher temperature.  I've gone a step
farther and hung up a curtain around my bed and only air condition the air
around the bed using a portable unit.  The portable unit is on wheels and has
a hose that connects to a window opening to conduct the hot air and condensate

I used a hospital-type curtain.  If you have a SWMBO to keep happy, you can do
a 4-poster bed with an overhead and side curtains.  With the central AC set to
80, my little 8,000 BTU portable unit only runs about 30% of the time.  I
plotted energy used to remove the hot soak vs operating time at night and
found that about 80 degrees was the sweet spot for my house and heat pump and
sleeping habits.  I have the programmable thermostat turn the central unit
down to 70 about 15 minutes before I get up.  It's not that cool yet when I
get up but it's headed down rapidly.

I have another portable unit that I use in my den to directly cool me while
I'm computing or reading or whatever.  Again, I can turn the central
thermostat up much higher than normal and still be comfortable.

One other comment.  If your refrigerator is more than about 10 years old then
it'll pay to get a new one.  New refrigerators are remarkably efficient as
compared to the old ones.  My new one uses barely 1/10th the energy of the 80s
vintage that I replaced.  You'll need to get a KAW ($20 online) and check
yours to see where it's new enough to be energy-efficient, of course.


From: John De Armond
Subject: Re: Gas Dryers
Date: Mon, 01 Sep 2008 14:04:49 -0400
Message-ID: <>

On Sun, 31 Aug 2008 17:03:04 -0700, Winston <> wrote:

>Neon John wrote:
>> You ought to do an energy audit on yourself.  It's hard to save energy until
>> you know where it's actually going.
>Thanks for the info.  I shall re-read and ponder.
>I admit I'm challenged by the amount of activity it takes to
>do a proper energy audit. Where does one buy a 'smoke stick'

HVAC wholesaler?  Got me.  I don't do that kind of energy audit with the house
pressurization fans and the infrared cameras and all.  I just look at energy
usage.  Much of my work is commercial/industrial where there is little control
over the physical plant.  What I do is look at each significant energy
consuming device in the place (including lighting) make a tally and then
recommend alternatives including changes in procedures and practices.

You can do the same thing yourself.  Unless you're going to spend a LOT of
money for things like different wall insulation or high E windows, the full
blown energy audit probably isn't worth it.  You can spot leaking around
windows and stuff, either with your hands or an infrared thermometer, and
caulk as needed.

It's remarkable how much electricity you can save just by knowing how much
each appliance uses.  Some devices should be changed out.  With others you
alter your use patterns.

One small "fer'instance".  I keep a pot of coffee at hand at all times.  I'm a
coffee guzzler.  For years I let the Mr Coffee-type brewer just sit there
keeping the coffee warm.  Then I measured the damned thing.  I was amazed at
how much energy it used.  I understood once I analyzed its operation.  Not
only does the warming eye use power but also the brewing heater is kept hot
all the time. (this isn't true on brewers with separate "brew" and "warm"
switches).  The damned thing was using almost $20 a month in energy.

I yard-saled the thing (getting almost what I paid for it :-) and bought a
brewer that drops the coffee into a thermos carafe.  The coffee brews, the
brewer turns off and the coffee is kept hot by the vacuum bottle.  The new
brewer paid for itself in the first month or two of ownership.

Another area to look at is phantom loads.  That is, power that gadgets draw
when they're "off".  My laser printer draws less than 10 watts in sleep mode
but my laptop still draws over 30 watts.  30 watts * 732 hours in month =
22kWh.  At 8 cents a kWh, that's $1.75.  That's a buck seventy five a month
that I'd been paying for having my laptop instantly available when I opened
the cover. (yeah, I know, I figured it on 24 hrs/day.)  Plus the cost of air
conditioning out the heat.

That doesn't seem like all that much but if you're typical, you'll have 25 or
more wall warts and gadgets with electronic "off" switches scattered around
your house.  The remote controlled TV and stereo are in that category.

Even if you only save $20 a month, that's an extra meal out a month.


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