What is more energy efficient ?

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Stux said:
And I think the maths goes completely out the window if you're going to run a temperature controller
Wouldn't it still be relative? It would have the same efficiency on the motor and insulation. Both together would work less at a warmer tempeture.

In my younger years when I done my trade, I was a Sheet metal worker who specialised in air conditioning. There was 1 rule I remember my boss saying. That for every degree of coolness you require from ambient is a factor of power. I've found a freezer normally set at -18, being set at 4 using a stc-1000 will use approx 1/2 the power. So in the above example the $31 power cost difference becomes $15.50. We can relate that power usage back to the difference against ambient temperature rule. Say ambient is 25c, and fridge at 4c. So it needs to cool 21c difference. With ambient at 25c and fridge at -18 (typical freezer temp) we have a difference in temperature of 43, which is basically double the 21c difference at fridge temps, and that corresponds to my findings with the power meter.

QldKev
 
Which is I believe what Qldkev actually measured with his pigeon pair
 
 
Gryphon Brewing said:
Bit like Fords and Holdens really.
Nev
 

both cr@p... get a mazda... err i mean microwave :)
 
QldKev said:
Wouldn't it still be relative? It would have the same efficiency on the motor and insulation. Both together would work less at a warmer tempeture.

In my younger years when I done my trade, I was a Sheet metal worker who specialised in air conditioning. There was 1 rule I remember my boss saying. That for every degree of coolness you require from ambient is a factor of power. I've found a freezer normally set at -18, being set at 4 using a stc-1000 will use approx 1/2 the power. So in the above example the $31 power cost difference becomes $15.50. We can relate that power usage back to the difference against ambient temperature rule. Say ambient is 25c, and fridge at 4c. So it needs to cool 21c difference. With ambient at 25c and fridge at -18 (typical freezer temp) we have a difference in temperature of 43, which is basically double the 21c difference at fridge temps, and that corresponds to my findings with the power meter.

QldKev
I reckon the difference quoted would be due to "normal household use" regarding daily opening. It'd reduce to a very small difference in a keezer situation.
 
So I think it's safe to say to answer Smoop's original question, an upright fridge or upright freezer or chest freezer from the same age, all seem to have a minimal difference in power consumption. So you are better of choosing what shape best suits the requirements and your back.

QldKev
 
would there be any difference in efficiency/costs in using a temp controller stc1000 versus a fridge/freezer thermostat in a keezer? or even say life of keezer?
cheers
pat
 
I installed a little 80mm fan on my chesty and despite the marginal increase in power (running the fan at 4.5v), the temperature in the freezer is both lower (as per the STC1000 thermometer inside it) and the freezer itself seems to turn on much less frequently.

Having not owned a fridge for my kegs i can't comment on their power usage but common sense tells me that with thicker insulation on a freezer, it's bound to retain and maintain cooler temperatures for longer and be able to hit those temps 'easier' since it's got more grunt (think of a v8 getting to 100km/h faster than a v6, even though they both maintain the same speed once there).
 
bowhunterslodge said:
would there be any difference in efficiency/costs in using a temp controller stc1000 versus a fridge/freezer thermostat in a keezer? or even say life of keezer?
cheers
pat
I would say nothing worth noting. The only difference I can see is the power to maintain the LED screen display on the STC1000.

Nick JD said:
What's it use when frozen? That's surprising how little difference it makes, but I s'pose once a freezer is at -18C, maintaining a temperature costs roughly the same with super insullation.
Sorry Nick, I have never used this freezer frozen so I do not know. I am interested to find out now but it usually has 3-5 full kegs and I don't have anywhere to put them in the meantime.

joshF said:
I installed a little 80mm fan on my chesty and despite the marginal increase in power (running the fan at 4.5v), the temperature in the freezer is both lower (as per the STC1000 thermometer inside it) and the freezer itself seems to turn on much less frequently.

Having not owned a fridge for my kegs i can't comment on their power usage but common sense tells me that with thicker insulation on a freezer, it's bound to retain and maintain cooler temperatures for longer and be able to hit those temps 'easier' since it's got more grunt (think of a v8 getting to 100km/h faster than a v6, even though they both maintain the same speed once there).
My 12v 120mm fan doesn't even kick over 1c of difference in power consumption in 5 days so that is irrelevant
imo. What is relevant is the fact that having this running does improve the air circulation inside the freezer and possibly helps make it cycle on/off less often.

I have had both a fridge and now a freezer and they both hold their temps as one would expect, ie. no difference worth while mentioning albeit if you open the fridge door then that will rapidly lose more temperature than a freezer. However, I do not see why one would be opening the door all the time anyway.
 
probably should take into account deadspace, for eg my fridge holds 4 kegs with a shelf on top with odd bottles/glassesnd yeast vials, the kegs are a tight fit, so when full store a fair amount of thermal energy. With a chesty with the hump it may be harder to utilize the space. So maybe if you have 4 kegs @ 75l, then a 140l fridge maybe better than a 185l freezer or vice versa.
Probably stuff all.
Think I'll have a beer.
 
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