Archive for July 2010

Walk-In Update

Walk-in Fridge

Fridge Swap
We had to swap out the refrigerator we were using to power the walk-in for an upright freezer. As you can see from the temperature graphs below, the fridge just couldn’t keep up. It was running for 8 hours straight, would shut off for 30 minutes, and then run for 8 hours again. Now, with the upright freezer in place, it runs for about 30 minutes, and turns off for 30 minutes. (The spots where the graph drops to 0 is when the data logger stopped working). Each graph is one day, midnight to midnight.

Refrigerator Powering Walk-in:

FridgeGraph5-26-10 FridgeGraph5-27-10 FridgeGraph5-28-10

The sudden changes here are due to me playing with the unit trying to get it to work better…

Upright Freezer Powering Walk-in
Finally, the unit is cycling in a normal manner… based on my measurements of the fridge before setting it up as a walk-in, this is how it should look.(The missing data on 5/29 is the switch from the Fridge to the Freezer unit, you can see on 5/29 and into 5/30 the time it took the freezer to cool off the walk-in and then on 5/30 the start of the on/off cycling. On the 5/31 graph you can see the on/off cycling moving closer together as the fridge unit gets closer to the ideal temperature, then as we walk in and out of the room, it warms up and the fridge runs longer to balance out.

FridgeGraph5-29-10 FridgeGraph5-30-10 FridgeGraph5-31-10 FridgeGraph_Legend

2010-07-21_IMG_3098 2010-07-21_IMG_3099


Power Usage
(original house refrigerator)
The first table is my baseline for my beer fridge as it sits right now, an old house refrigerator that we got for free. I have cleaned up the coils and such, took out the shelves, but otherwise unmodified. It runs under it’s own temperature controller and according to the thermometer I have in there, it is currently running at 38*f. According to my power bill, I get charged $0.055 USD per Kilowatt Hour (KWH); I have Xcel Energy in the Denver Metro area of Colorado.

Baseline as a Regular Refrigerator
(Rate of $0.055/KWH @ 38*f)

Standby Mode
w/ Light On
Running
Running w/Light
Volt
122.70
122.60
121.40
Amp
0.06
0.39
4.32
Watt
6.00
48.00
304.00
VA
10.00
48.00
520.00
Hz
59.90
59.90
59.90
P.F.
0.79
1.00
0.59
Cost/Year
$68.89
Cost/Month
$5.66
Cost/Week
$1.32
Cost/Day
$0.18
Cost/Hour
$0.00
Hours Ran
1217.00
Total Cost
$9.58
Total KWH
174.00

This second table will be the power usage after I take the refrigerator doors off and push it up to the opening in the walk-in to use it to power the walk-in. I plan to let it run as long as I can practically empty, and measure it. (This idea was scrapped due to the fridge unit not being able to keep the room cool enough, so I moved on to testing stage 2: fill the room with water to help is save power). Then I will fill the space with as much liquid as I can (beer, kegs, carboys, etc), even if it is just with water, to see the difference in power usage keeping the fridge full vs empty. This way I can prove it is worth it to keep lots of beer on hand at all times.