Posted by drydem on August 10, 2008, 4:55 pm
> drydem wrote:
> ...
> > I used the fuel cost - 16 cents per 1kwh - which I remembered from
> > last spring.
> > I looked back on my electric bill today and realized you are correct -
> > my bill
> > for last month is $78.20 for 450 kwh which translates to about 17
> > cents per 1 kwh.
> > What I didn't include in my ROI calculation was the 75 dollar rebate
> > that I
> > supposedly will get back from the delivery charge (I haven't received
> > it as
> > of yet). Since I am not financing this purchase - there is no cost for
> > the
> > capital. The kill-o-watt meter is on loan from the public library.
> You do have capital costs even if you don't finance because if you
> didn't spend that money on the refrigerator you could either put it
> in some long term investment (a CD with a term similar to refrigerator
> life time?) or use it to pay down or off some other loan (mortgage?).
> These are also sometimes called oppportunity costs. The choice of
> interest rate to use for you analysis is not obvious, though.
short answer:
===========
The capital opportunity cost was not a signficant factor.
long answer:
============
if i didn't repair or replace the fridge - the food would go bad -
I don't want to sound flippant but other than my investments in
energy and commodities - most of them have performed poorly
or lost money in recent times. Outstanding loans are irrelevant
Loans are structured such that their cost are normally
higher than the return of any conservate investment and normally
higher than all but the most riskiest of investments. A person
paying off a costly loans does so because of reason outside the
scope of my analysis ( one might say that's a personal issue
not a technical one - and thus is a irrelevant to the analysis)
Unlike- some emerging economies - developed economies
require large amounts of capital which limits opportunities
- return on conservative investment like CD are poor.
Considering that inflation on food items is very high - anything
that allows one flexiblity in buying foodstuff has a very
high economic value and can be though of as an. investment.
For example, that T-bone steak you have in the freezer
which cost 4.99 two weeks ago is now selling for 14.99
at the local supermarket. About a year ago I bought
a 20lb bag of rice for 7 dollars - today that same bag of
rice cost 15 dolars.
Ignoring the energy savings of a new refrigerator and
the saving had by timing your food purchases,
let's consider how much one might earn from the money
not spent on a new fridge by repairing the old fridge.
The initial difference in capital cost between repairing it
yourself ( given you are a competent electrician) and
replacing it is about 671 dollars (721-50). The capital
cost for repairring it and replacing it would problably
be abou 500 (estimated labor cost 171).
$671 to $500 might get you a 3% 1 year CD - which
at the end of 8 years would amass $179 and $133
respectively ( the net earnings after taxes would be
about $134 and 100 assuming we dont have any
huge tax increases) - Unfortunately - the amount
being saved is too small amount to get municipal
bonds which would be free of federal and local
tax -- so that option is off the table. At the end
of eight years because of compound interest
your CD' gross earning would be 24.76 and
18.46 (the annual net earnings after taxes
would be about 18 and 13 dollars. So even if
energy cost were to stay flat net -- earnings
for any conservative investment would not be
be significant - a riskier investment might also
incur a loss of capital.
Posted by daestrom on August 10, 2008, 4:17 pm
Vaughn Simon wrote:
>> Conclusion:
>> -------------
>> Energy star applicances appears only justifable if one is going to
>> use it for over 8 years
>> Even getting a new non-energy star refrigerator would povide some
>> energy saving over repairing and keeping a much older refridgerator.
>> The energy efficiency of a refrigerator is significantly impacted by
>> the room temperature
> Wow! Thanks for a well-done and informative post.
Agree.
<snip>
> 1) The defrost system. This consists of a timer and one or more
> heaters inside your freezer. The heaters tend to burn out after
> about 5 years, but your freezer often just displays diminished
> performance thereafter without ever failing completely. Unfortunately,
> there is no easy way to check this. One way is to
> turn off the unit, open the door for an entire day, and observe how
> much condensate is still dripping out of the unit hours later. If
> you get LOTS of water, and it keeps dripping for hours and hours, and
> you can still feel something cold in the back of your freezer, then
> you can safely assume that the unit needed defrosting. After you
> allow it to completely defrost, the unit should work better for a few
> weeks.
> You can buy the parts and find replacement instructions on the
> Internet. I did mine for about $35.00 in parts. The only tool I
> needed for the job was a screwdriver. (My wife was terribly
> disappointed at my success, she wanted a new refrigerator)
> 2) Dust buildup on the condenser or bad fan. Find your condenser
> (probably under the bottom). Blow out the dust. If there is a fan,
> make sure that it is in working order.
A third 'failure' is a bad door seal. If you feel cold air on the floor in
front of the fridge when the door is closed, you have a seal problem and are
wasting energy. Easy fix.
daestrom
Posted by bealiba on August 10, 2008, 12:19 am
> Several months ago I posted energy usage data on my old refrigerator
> [1] - I was debating on whether to replace my old fridge or not...
> During that winter, I used a Kill-O-Watt Meter to measure the energy
> usage of my old 18.6 cubic feet Kenmore refrigerator (model 8389210).
> The 19 year old fridge was drawing about 1.4Kwh per day or about 511
> Kwh/month. The old refrigerator's listed estimated energy cost was
> $63.00 (at 6.75 cents per kwh) which translated to an estimated energy
> usage of about 933 kwh/year - so I was initially surprised at the
> variation. At the time I thought it might be due to my usage. At that
> time in November, my freezer section was running at about 10 degrees
> Fahrenheit and refrigerated section is running at 38 degrees
> Fahrenheit [2]. Given that the ambient temperature was cooler (about
> 67 F) in the winter, I said I would measure the energy usage during
> the summer to identify any variation in energy usage[3]. As pointed
> out by a Mr. David Williams [4], at 10 degrees F the freezer was
> underperforming – a hint that that it was dying.
> By the summer, the freezer failure was obvious – the freezer section
> was unable to get colder than 20 degrees Fahrenheit. Rather than
> repaired it - I decide it would be a good time to replace the old
> refrigerator with a new energy star refrigerator. I decided to get a
> energy star 20.6 cubic feet top freezer refrigerator from Kenmore
> (model 253.6817280) which is rated at 408 kWh/year [ This model is
> slightly more energy efficient per cubic foot than the 18.0 cubic feet
> Kenmore version which uses 383 kWh/year]
> Before replacing the old fridge – I decided to measure its energy
> usage again. This time I was only able to record the energy usage for
> less than two days. On the last days of the old refrigerator, it was
> using about 3.28 kWh/day which is equivalent to 1154 kWh/year - much
> higher than 1.4 kwh/day and 511kwh/yr energy usage rate during the
> winter. Since its the summer time the ambient room temperature is
> much higher at about 80 degrees F in the afternoon and 76 degrees F in
> the evenings. My usage of the old refrigerator has not changed since
> November; however, the ambient room temperature is now about 15 degree
> F warmer. This suggests that the more significant energy usage factor
> (atleast in this situation) was the ambient room temperature - which
> in this case varies over the year -so the cost is lower in the winter
> and higher in the summer.
> So far I’ve had the new refrigerator hooked up to the Kill-o-Watt
> meter for about a week. The new refrigerator’s energy usage for 165
> hours is 9.31 kWh - which translates to 1.35 kWh/day. If this energy
> usage rate were to remain constant - it would translate to 492 kWh/
> year. Currently, the freezer temperature is at 0 degrees F, the
> refrigerated temperature is at 36 degrees F, and the current ambient
> room temperature swings from an afternoon high of 82 degrees F to an
> evening low of 72 degrees F. As observed previously with the older
> refrigerator, the new refrigerator’s energy usage rate will probably
> be less when the ambient room temperature drops during the winter
> months so I am thinking of doing another measurement in six months.
> As far as ROI - the cost for a energy star refrigerator is about 100
> dollars more than a non energy star refrigerator of the same size
> given similar featues.
> 449.99 = 18.0 cubic feet non-energy star refrigerator (479 kwh/year)
> 499.99 = 20.6 cublic feet non-energy star refrigerator (498kwh/year)
> 549.99 = 18.0 cubic feet energy star refridgeator (383 kwh/year)
> 599.99 = 20.6 cubic feet energy star refrigerator (407kwh/year)
> my cost broke down as follows:
> 599.99 = 20.6 cubic feet energy star refrigerator (407kwh/year)
> 085.00 = Delivery/Haul away
> 036.00 = taxes
> 720.99 = total cost for a 20.6 cu ft energy star refrigerator
> Currently the cost of electricity is 16 cents per Kwh.
> At that price one would need to save 625 kwh to justify
> the extra $100 spent on the energy star version.
> If the appliance energy usage rating ae somewhat close
> then the non-energy star version uses 91 kwh/yr more per
> year than the energy star version. So it will take
> seven years to justify the cost of getting an energy star
> fridge over a non-energy star version if current electrical cost
> stay stable.
> The energy saving per day for the summer days is
> 3.28kwh/day - 1.35kwh/day= 1.93kwh/day
> That is to say the new fridge is 59% more energy efficient
> than the old refrigerator. A non energy star refrigerator
> would likely use 1.69kwh/day but still save
> about 1.6kwh/day
> .
> Conclusion:
> -------------
> Energy star applicances appears only justifable if one is going to use
> it for over 8 years
> Even getting a new non-energy star refrigerator would povide some
> energy saving over repairing and keeping a much older refridgerator.
> The energy efficiency of a refrigerator is significantly impacted by
> the room temperature
> [1]
> Newsgroups: alt.energy.homepower
> Date: Thu, 15 Nov 2007 04:12:24 -0800 (PST)
> Local: Thurs, Nov 15 2007 8:12 am
> Subject: Re: Question on Power Consumption limiting (A/C, ovens etc.)
> [2]
> Newsgroups: alt.energy.homepower
> Date: Tue, 20 Nov 2007 17:36:21 -0800 (PST)
> Local: Tues, Nov 20 2007 9:36 pm
> Subject: Re: Question on Power Consumption limiting (A/C, ovens etc.)
> [3]
> Newsgroups: alt.energy.homepower
> Date: Thu, 22 Nov 2007 02:18:33 -0800 (PST)
> Local: Thurs, Nov 22 2007 6:18 am
> Subject: Re: Question on Power Consumption limiting (A/C, ovens etc.)
> [4]
> Newsgroups: alt.energy.homepower
> From: david.willi...@bayman.org (David Williams)
> Date: Tue, 20 Nov 2007 23:00:03 -0600
> Local: Wed, Nov 21 2007 1:00 am
> Subject: Re: Question on Power Consumption limiting (A/C, ovens etc.)
Google Blomberg Arcelic CT 1300A. A vacuum panel fridge that is
claimed to use just 130kWh/year
Posted by Tommy on August 11, 2008, 12:26 pm
Gald to see you took the time to track all the info. Fridges can be a
good percentage of kwh per month.
Anyway, I didn't see it mentioned. Frig Insulation has come along way in
the past few years. Some people is adding insulation to fridges, and
freezers. I was able to apply 3/4" foam insulation to the existing foam
insulation which covered the entire back of the fridge. Compressor
compartment was left open, with nothing being blocked. Note, read
somewhere "maybe MotherEarth News" not to cover areas where the cooling
cools, and defrost heaters are.
I also replaced my fridge with a non-energystar.
Was not worth the extra money.
Tommy
Posted by drydem on August 12, 2008, 5:52 am
On Aug 11, 12:26 pm, jeeppin...@webtv.net (Tommy) wrote:
> Gald to see you took the time to track all the info. Fridges can be a
> good percentage of kwh per month.
> Anyway, I didn't see it mentioned. Frig Insulation has come along way in
> the past few years. Some people is adding insulation to fridges, and
> freezers. I was able to apply 3/4" foam insulation to the existing foam
> insulation which covered the entire back of the fridge. Compressor
> compartment was left open, with nothing being blocked. Note, read
> somewhere "maybe MotherEarth News" not to cover areas where the cooling
> cools, and defrost heaters are.
> I also replaced my fridge with a non-energystar.
> Was not worth the extra money.
> Tommy
Unless I opted for a smaller refrigerator - 15 cubic feet or less -
the
kitchen space set aside for the refrigerator would not allow adding
any significant amounts of insulation. Exposed insulation would
also be a fire hazard in the kitchen so it would have to be shielded
in some way. If the freezer or fridger was located in the
basement ( away from any fire hazards) additional insulation
would be easier to do ( and the impact of visual esthetics
of additional styrofoam panels could be minimized).
Given that many people don't stay in one place for
over 4 years or make plans for that long - most of
the energy star electric applicances fail to provide
any significant cost saving to justified their extra
cost - without a tax incentive, it is difficult to justify
their additional cost if energy prices stay stable or
only increase gradually. The only way energy star
cost premium might be justifiable would be if the
cost of electricity/energy went up dramatically
for a significant portion of the lifespace of the
device/appliance.
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> ...
> > I used the fuel cost - 16 cents per 1kwh - which I remembered from
> > last spring.
> > I looked back on my electric bill today and realized you are correct -
> > my bill
> > for last month is $78.20 for 450 kwh which translates to about 17
> > cents per 1 kwh.
> > What I didn't include in my ROI calculation was the 75 dollar rebate
> > that I
> > supposedly will get back from the delivery charge (I haven't received
> > it as
> > of yet). Since I am not financing this purchase - there is no cost for
> > the
> > capital. The kill-o-watt meter is on loan from the public library.
> You do have capital costs even if you don't finance because if you
> didn't spend that money on the refrigerator you could either put it
> in some long term investment (a CD with a term similar to refrigerator
> life time?) or use it to pay down or off some other loan (mortgage?).
> These are also sometimes called oppportunity costs. The choice of
> interest rate to use for you analysis is not obvious, though.