STC-1000 Power Usage

[brewermp]

Hi All,

This is a how long is a piece of string question and I am not looking for a specific answer just each individuals experience.

Has anyone done any reviews on power usage with a STC1000, a fridge and a heating device?

Now there are several things which would affect power usage. These being

• insulation of fridge
• Ambient tempreature
• Tempreature spikes
• Cooling efficiency
• heating efficiency
• yada yada

I am going to set a stc1000 up as I saw a cheap bar fridge for $10 and have a belt heater already .

I know, I know an old fridge alone will chew a heap of power but my ambient tempreature in the cellar doesnt change much so just wondering how hard everyones fridge/heaters work on the stc1000.

I will hopefully answer my own question in a months time when I plug it into a power meter and will post results up here.

 

[MartinOC]

Yep, it's been done many years ago, but buggered if I can remember what thread it was in. Someone got really anal & data-logged a couple of fridges before & after installation of controllers.

Bottom-line? Using an STC-1000 will reduce your power consumption for any given unit, but as you noted, there are lots of other variables that will affect ACTUAL power consumption of that unit.

If you're using it as a fermentation fridge (which I'm guessing you are, since you mentioned a heat belt), then the benefits of controlled fermentation temperatures far outweighs concerns about power consumption, when quality of final product is concerned.

Unless you're a real geek & like recording things & looking at spreadsheets & graphs, just RDWHAH & accept the benefits.

 

[Bomber Watson]

Were averaging about 35 degrees during the day here atm, and my 200lt chest freezer with a STC1000 is currently keeping two brews cold crashed at 2 degrees only kicking in three to four times a day, and only for a minute or so.

So, not much power.

Cheers.

 

[brewermp]

Awesome . I'm steadying between 18-24 in the cellar but it's not consistent. Will keep this post updated when I do some calculations.

 

[QldKev]

A few pointers I have found
Within reason a STC will not reduce power usage more than a fridge set to the same temperature. It will allow you to set what ever temp you desire.
Fridges / freezers use more power for every degree they get from ambient. So in a 20c room a fridge running at 10c will use approx half the power as one at 0c. So an all fridge is cheaper to run than a fridge freezer combo.
Then comes insulation, which often has improved but not by huge amounts with 10 year periods. Another issues is seals, a leaky seal will suck a lot of coolness out of the fridge, hence the fridge will cost a lot to run. Finally each generation of compressor does get more efficient, once again look for many years apart for improvements.
I've read many claims of fridges/freezers using a lot less power than the manufacturer claims. People also claim ufo sightings. (not a dig at anyone in particular)
Chest freezers do not have some magic insulation, so if both an upright and a chest fridge/freezer are not opened they will use approx the same power. But when an upright is opened a lot of the cold air can/will drop out. Not so good if you need to open it frequently, not so bad if you only open it once a week.
The Westinghouse fridges site lists all the power consumptions for their whitegoods, a great place to get a good idea. But allow what temperature they expect the fridge to be used at Vs what you are running it at.


Have a read here of my measured usage around my home

 

[MartinOC]

AHA! It was QldKev who was the anally-retentive I alluded-to earlier... :beerbang:

 

[QldKev]

AHA! It was QldKev who was the anally-retentive I alluded-to earlier... :beerbang:

Someone else did actually log a before STC and after, not me. I logged everything else

oops, I haven't checked if the daylight globe is cheaper on power than a warm white yet for the same wattage. But a warm white would have to hold back more light energy hence heating up the ballast more h34r:

 

[Adr_0]

Will an STC-1000 automatically kick in heat belt when below setpoint and fridge when above?

Be careful if you use your temp probe in the wort as there is a normally a bit of lag in the reading. If you use both a freezer and heat belt, you will get some overshoot and the heat belt/freezer constantly fighting each other.

I have a Keg King controller and during a test run the freezer would kick in at (say) 18.3°C and overshoot to 17.7, where the heat belt would kick in and overshoot again. So something was on continuously.

[SIZE=13.63636302948px]The solution for me - in this application where there is a fair bit of mass and reading temp in the middle of the wort - has been setting the hysteresis to 0.1-0.2°C and just disconnecting the heat belt. Generally healthy yeast will warm things up if needed. I may need the heat belt for raising temps (gently) at some point, but not for control to a steady temp. Freezer goes on a few times a day like most peoples' experience.[/SIZE]

 

[Bomber Watson]

You can set both how many 10ths of degrees over your set point each item kicks in, and also set in a delay time, so a time the unit waits after the set point above/below the set point is reached before it does anything, so with a bit of tweaking you can get it pretty good.

Cheers.

 

[Nizmoose]

Not to go too off topic but if you wanted to maintain say 16 degrees to avoid the lag problem wouldn't you want to set your controller to a certain temp (say 15.5 to take into account fermentation heat) then have the probe measure the ambient temperature? If it's measuring ambient and maintaining it for the entire fermentation and can hold it steady the beer is going to stay at whatever temp steadily because the air around the fermenter will respond much more quickly than the beer thus preventing that overshoot

 

[Bomber Watson]

Na the probe in air is to sensitive, as the freezer kicks in it cools the air to x but it warms quickly (comparatively) back to Y, for example. The big pool of liquid in the middle does not change temps this fast, so your unnecessarily switching the fridge/freezer on an off far to many times.

I have my probe stuck to the side of one of my fermenters covered with four layers of bubble wrap, seems pretty good.

Cheers.

 

[brewermp]

Yep heard bubble wrap or foam is the go. Also who would wanna risk infection. Outside temp of your FV in a fridge is almost identical to the wort temp if it's setup correctly.

 

[Bomber Watson]

Air is one of the best insulators we have at out disposal.

Bubble wrap is mostly air.....

Airs insulating properties can work both with us and against us, in this case, in my very limited experience, it seems to work for us well.

cheers.

 

[Nizmoose]

Ahh very good point didn't think about the variation cheers for clearing that up

 

[Adr_0]

many many ways to skin a cat with these things. the topic was on power usage, so whichever way you go you don't want the controller to be bouncing off low and high temps, kicking in the freezer/heat belt at each end. find a way to make sure it doesn't do this.

either way, a large volume of water/wort will bounce a lot less than empty space in the freezer.

the probe taped to the side of the fermenter with a couple of layers of beer coolers (a small square then a big square) is a pretty solid solution, cheap, and easy. I haven't done this before but it's probably the best balance of accuracy, stability and cheap/easy.

for those who are worried about infection with the probe in the wort, I have two things to say:
1) with respect, lol; and
2) use a thermowell