Posted by Crappy on May 8, 2009, 12:34 pm
Hopefully someone here has an idea.
I have been monitoring my energy usage (with www.myenergyusage.net)
and noticed through out the day, every hour for 45 minutes, there was
a higher usage. About an extra 150-200W. it is my fridge. I turned it
off for a few hours and the graphs reflected this.
I hooked up a temperature logger and monitored the fridge for a few
days. It's set to 5c and really struggles to get to it. The ambient
room temperature is about 18-20c during the day, about 16 at night.
Open the door for a few seconds, as in getting the milk out, and the
temp rises by 2-3 degrees as expected. What is not expected is the
time it takes for it to come back down. A good 15-20 minutes before it
starts dropping again.
During the day when no one is home, it fluctuate as well. Up a degree
to two and comes back down.
I changed the temperature to 6c and it's worse than before. Internally
it hovers around 8-9c. Not the 6 I asked for.
The fridge is only a year old. I cannot remember the energy band
though but was not the cheapest one the floor. It's an LG double door.
(Sorry - cannot remember model)
Feeling the vents inside, the air coming out of them is cold so
compressor seems ok. Both the fridge and freezer are full(ish). not
packed but not empty. The temperature sensor is located middle top /
bottom and center left / right and not obstructed or shielded and is
My question is: Is this normal? Is the common fridge's duty cycle that
high? I intend switching it off for 2-3 hours to see if it is an
insulation problem though I doubt.
Posted by Eeyore on May 8, 2009, 2:00 pm
Sounds like you need one with better insulation.
You do know to close the door instead of leaving it open for minutes at a
time don't you ?
Posted by Scott on May 8, 2009, 2:10 pm
On Fri, 8 May 2009 05:34:34 -0700 (PDT), in alt.energy.homepower, Crappy
You've made sure the condenser is clean and has free airflow? Also check
that the evaporator isn't iced up; my refrigerator had similar symptoms when
the defrost timer failed allowing the evaporator to begin accumulating ice.
Posted by Don Young on May 9, 2009, 1:29 am
It seems to me that your refrigerator is working normally for a
high-efficiency unit. They tend to have lower power usage when running but a
higher duty cycle. Just be sure the unit is clean and the door gasket seals
You have discovered one of the pitfalls of increasing information. I had a
friend many years ago who installed an accessory ammeter in his car. He had
no electrical problems before installing the ammeter but afterwards was
forever finding something not right about his electrical system. ;>)
Posted by residualselfimage1999 on May 9, 2009, 11:23 am
1. If the door seals are okay and the fridge is very new then
insulation is not a likely cause.
2. You can measure the exact power usage with a plug-in device called
a "Kill-Watt" meter
in my jurisdiction you can borrow one from the public library.
3. Below is a link to a description of the energy usage for a 20 cu
ft. energy star refrigerator.
It is using 1.35 kwh/day or 56 wh/hour which is much less than your
4. Refrigerators have external heat exchangers - in the old days they
were exposed air
colled coils - however, Today's modern version are not exposed
and exist under
the rear or top panel of the unit - when the unit's compressor is
working the cooling
panel should be warm to the touch and should be clear and free
air space around it
to allow for proper air circulation (about 4 to 6 inches of
ventilated air space should do it)
The unit's energy efficiency depends to adequate air circulation
for its heat exchangers.
If this is not the case - reposition your unit so that it has
adequate air circulation
around its heat exchanger.
5. If you unit is still under warranty, you should seriously consider
in for a service check.