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koolzoner
11-11-2016, 01:04 AM
Is there a way of calculating how much energy you could save by optimising your refrigeration unit? For example, if a freezer was set to -20 and it only needs to be at -18, how much energy could be saved by changing the setting to -18?

Many thanks!

Segei
11-11-2016, 01:27 AM
Heat transfer to the room will be reduced and energy will be saved. Heat transfer is proportional to temperature difference between inside and outside. Assume that outside temperature is 20C. Initial temperature difference is 20 - (-20)= 40C If inside temperature changes to -18C, temperature difference will be 38C. Energy savings will be (40-38)/40=0.05 or 5%

koolzoner
11-11-2016, 11:33 AM
Many thanks for your excellent reply!

koolzoner
11-11-2016, 03:05 PM
One last question, do you know much electricity a fridge, freezer or cold room would use say in a month, just estimates?

Thanks in advance!

Rob White
11-11-2016, 04:04 PM
.

1Kwh is about 12p so if you had an electric motor that
was one Kilowatt in size it would cost about 12p an hour to run.

If your compressor was about 500w then it would cost 6p an hour.

Most fridges and freezers when the door is closed should be off for
longer than they run, so if you had a small chest freezer with a 300w
compressor on it would cost 4 or 5 pence an hour over say 10 to 12 hours
a day.

4p for 10 hours is only about 40p a day, 5p for 12 hours is about 60p a day

4 to 6 every 10 days, 12 to 18 a month????????

All rough and off the top off my head so there will be a margin of error :D
if my maths are wrong............

Rob

.

Josip
11-11-2016, 07:10 PM
.

1Kwh is about 12p so if you had an electric motor that
was one Kilowatt in size it would cost about 12p an hour to run.

If your compressor was about 500w then it would cost 6p an hour.

Most fridges and freezers when the door is closed should be off for
longer than they run, so if you had a small chest freezer with a 300w
compressor on it would cost 4 or 5 pence an hour over say 10 to 12 hours
a day.

4p for 10 hours is only about 40p a day, 5p for 12 hours is about 60p a day

4 to 6 every 10 days, 12 to 18 a month????????

All rough and off the top off my head so there will be a margin of error :D
if my maths are wrong............

Rob

.

Error or not within your math for sure will be a margin of error ...

but moral of the story is ...
to make savings we need to keep our fridge or freezer closed most of the time :D


Best regards, Josip

Magoo
11-11-2016, 10:16 PM
Cycling off evaporator fans with temperature controller, saves money twice, fans add heat to room then uses power to remove that heat, start fans intermittently in off cycle for short periods.

koolzoner
11-11-2016, 10:59 PM
.

1Kwh is about 12p so if you had an electric motor that
was one Kilowatt in size it would cost about 12p an hour to run.

If your compressor was about 500w then it would cost 6p an hour.

Most fridges and freezers when the door is closed should be off for
longer than they run, so if you had a small chest freezer with a 300w
compressor on it would cost 4 or 5 pence an hour over say 10 to 12 hours
a day.

4p for 10 hours is only about 40p a day, 5p for 12 hours is about 60p a day

4 to 6 every 10 days, 12 to 18 a month????????

All rough and off the top off my head so there will be a margin of error :D
if my maths are wrong............

Rob

.

Thanks very much,exactly what I was looking for!