fridge use power saving
val189
luxury cruise, but ....
Is it better to stand there with the fridge door open, packing away a
ton of food for, say, 30 seconds
OR
opening the door three times for 10 seconds average?
I always face this dilemma after a major grocery buying excursion and
hear that maternal tape in my head - you know, the one that intones
"Don't stand there with the door open" or "Are you drawing a
picture?" Or maybe you didn't have to grow up hearing this every day.
Rod Speed
> OK - I admit right off that the results of
> this poll won't pay for a luxury cruise, but ....
It isnt even gunna pay for a coffee either.
> Is it better to stand there with the fridge door open,
> packing away a ton of food for, say, 30 seconds
> OR
> opening the door three times for 10 seconds average?
No significant difference.
> I always face this dilemma after a major grocery buying excursion and
> hear that maternal tape in my head - you know, the one that intones
> "Don't stand there with the door open" or "Are you drawing a picture?"
Dont forget who will be picking her nursing home.
> Or maybe you didn't have to grow up hearing this every day.
No I didnt, but then I chose my parents more carefully than you did.
Gary Heston
Whenever you hear that maternal tape, just say "it's _my_ refrigerator,
mother!" and keep loading food. The difference between one 30 second
and three 10 second door openings is insignificant compared to the
monthly cost of running a refrigerator.
Gary
--
Gary Heston ghe...@hiwaay.net http://www.thebreastcancersite.com/
Yoko Onos' former driver tried to extort $2M from her, threating to
"release embarassing recordings...". What, he has a copy of her album?
val189
Beachcomber
wrote:
>Whew... thanks guys for relieving me of this tremendous burden. : ))
>
>
If you are concerned about efficiency and you have a lot of free space
in your fridge, you may want to fill it up with camping ice pack gels
or even bottles of water, soft drinks, etc. That way, if you ever
have a power failure, you will have an increased 'cold sink' mass
which should keep it cold for a lot longer (provided you keep the door
shut). Beyond the initial cool down of the increased mass, there is
no recurring expense.
The same principle applies to freezers.
nicks...@ece.villanova.edu
>If you are concerned about efficiency and you have a lot of free space
>in your fridge, you may want to fill it up with camping ice pack gels
>or even bottles of water, soft drinks, etc...
Why on earth would that raise the efficiency?
Nick
Usene...@the-domain-in.sig
<1183681362.7...@n2g2000hse.googlegroups.com>,
gweh...@bellsouth.net says...
> OK - I admit right off that the results of this poll won't pay for a
> luxury cruise, but ....
>
> Is it better to stand there with the fridge door open, packing away a
> ton of food for, say, 30 seconds
> OR
> opening the door three times for 10 seconds average?
My guess is that it is too small to measure.
Personally, I keep the fridge compartment slightly full, with
some containers of water. And then just randomly put in the
small amount of actual food, without further concern for
door-opening time.
Although I keep the freezer compartment full (or nearly so) with
bags of mixed vegetables (stock up when they're on sale), plus a
little fish and one ice cream.
Part of the issue is the cold air falling out, and being replaced
with warm air from the room. Which then has to be cooled, taking
energy. But, 1 x 30 or a rapid 3 x 10 probably isn't going to
make a noticeable difference.
--
Get Credit Where Credit Is Due
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Credit Tools, Reference, and Forum
throwitout
Because the compressor will then be running less often, but for longer
periods. As well it will be less likely to come on after the door has
been briefly open. Fridge compressors run more efficiently if run for
longer intervals than shorter ones.
val189
> The same principle applies to freezers.
I have already started my hurricane season 'cookdown'. Getting that
freezer down to almost no food - making huge icecubes -
I have know of people tossing a few hundreds dollars worth of food
after a long outage.
nicks...@ece.villanova.edu
>> Beachcomber <inva...@notreal.none> wrote:
>> >If you are concerned about efficiency and you have a lot of free space
>> >in your fridge, you may want to fill it up with camping ice pack gels
>> >or even bottles of water, soft drinks, etc...
>>
>> Why on earth would that raise the efficiency?
>
>Because the compressor will then be running less often, but for longer
>periods. As well it will be less likely to come on after the door has
>been briefly open. Fridge compressors run more efficiently if run for
>longer intervals than shorter ones.
Each start takes about 0.3 Wh, worth 0.3/1000x0.1 = $0.00003, so 24
starts per day would cost about 26 cents per year. You might reduce
this to 13 cents per year by adding a lot of bottles, but more cold
surfaces inside the fridge mean more airflow and condensation when
the door is open, which is a lot more expensive.
Nick
Logan Shaw
> throwitout <throw...@dodgeit.com> wrote:
>> Fridge compressors run more efficiently if run for
>> longer intervals than shorter ones.
> Each start takes about 0.3 Wh
Where does this number come from? Are you considering only the power
it takes to start up the motor, or are you also considering reduced
efficiency that the fridge might experience while reaching steady state
operation? I'm not saying I know that fridges do this[1], but many
systems behave this way (for example, cars run less efficiently while
they are warming up), and you would have to know whether fridges do
this in order to have something to base your number on.
- Logan
[1] Although it stands to reason -- my fridge has an electric fan
to blow air over the coil. During the time when the fan has
started running but the coil hasn't achieved its full temperature
difference with the ambient air, the fan is using the same
amount of electricity but accomplishing less. As is, come to
think of it, the motor for the compressor.
Rick
But you really didn't explain the "why" part. It makes them more
efficient, or maybe a better way to put it is it makes what is in the
appliance more efficient, to keep cold. A lot of air space - because
there is nothing else in the freezer - is not very efficient at staying
cold. But water or ice packs placed in the freezer, once frozen, do a
much better job of holding their temperature than empty air space ever
can. You're better off throwing those extra ice gel packs in the freezer
when you have the space to put them in there.
Rick
nicks...@ece.villanova.edu
>nicks...@ece.villanova.edu wrote:
>> throwitout <throw...@dodgeit.com> wrote:
>
>>> Fridge compressors run more efficiently if run for
>>> longer intervals than shorter ones.
>
>> Each start takes about 0.3 Wh
>
>Where does this number come from?
A PE friend that I trust.
>Are you considering only the power it takes to start up the motor,
How much net energy does that require?
>or are you also considering reduced efficiency that the fridge might
>experience while reaching steady state operation?
I would guess both, since he said this was a result of a calculation.
Do you have a more accurate number?
And how about the increased airflow and condensation
when the door is open, given more cold surfaces?
Nick
Logan Shaw
> Logan Shaw <lshaw-...@austin.rr.com> wrote:
>> nicks...@ece.villanova.edu wrote:
>>> throwitout <throw...@dodgeit.com> wrote:
>>>> Fridge compressors run more efficiently if run for
>>>> longer intervals than shorter ones.
>>> Each start takes about 0.3 Wh
>> Where does this number come from?
>
> A PE friend that I trust.
> Do you have a more accurate number?
No, but I'm not claiming to have one. :-)
> And how about the increased airflow and condensation
> when the door is open, given more cold surfaces?
Hmm, shouldn't it be decreased airflow since there is less
air and more physical objects blocking its flow? The
condensation question is trickier. I agree there are more
surfaces for condensation to collect on, but if a given volume
of (warmer, moister) air comes in, shouldn't there be a
fixed amount of condensation since there is a fixed amount
of moisture? It seems like the condensation is the same,
it would just be spread out over a larger or smaller surface.
- Logan
nicks...@ece.villanova.edu
>>>> Each start takes about 0.3 Wh
>>> Where does this number come from?
>> A PE friend that I trust.
>> Do you have a more accurate number?
>No, but I'm not claiming to have one. :-)
Neither am I.
>> And how about the increased airflow and condensation
>> when the door is open, given more cold surfaces?
>
>Hmm, shouldn't it be decreased airflow since there is less air and
>more physical objects blocking its flow?
More, because there's more heat transfer surface to make a larger
inside-outside air temp diff and increase thermosyphoning airflow.
Water bottles could block airflow if they were packed solid like
a brick wall, but bottles aren't bricks.
Nick