Part II: Refrigerator Efficiency: Trust but Verify

If you were to read the transcript of THE PRELIMINARY ANALYSES FOR RESIDENTIAL REFRIGERATORS, REFRIGERATOR–FREEZERS, AND FREEZERS, (The PARRRFF) all 244 pages of it you would learn of the deep concentrated efforts, the research, the analysis, done by manufacturers, regulators, and consultants, fighting to free America from the bondage of imported energy.

Patriots I tell you, each and every voice heard was the voice of a patriot.
(see Part 1 of this story),

Until reading this transcript I had thought most manufacturers to be lazy pigs making piggish energy sucking refrigerators, as opposed to the sleek energy sipping fridges I was sure they were hiding in the basement.  

Coincidentally, my personal 11 year old 25 cuft Kenmore top mount was on its way to the happy hunting grounds, making it available to try out some stuff. “So what the hell!” says me, let’s see if this thing can be made just a little more efficient.

The Test
With 1” thick R5 Extruded Polystyrene rigid pink insulation from the local hardware store, a roll of plastic box tape, I set to work applying it to the exterior sides of the fridge. Measuring, cutting and taping. Any idiot could do it, even a few of the idiots sitting at the table of The PARRRFF. All connections and seams were taped to reduce convective losses. 4 – 5 screws were also used for a tighter fit where necessary. The screw heads were themselves insulated.

In the end the fridge was completely insulated except for the bottom where the heat exchange was located, and the back where the fan exhausted.

Test equipment used: Kill-o-watt meter
Test plan:  Family uses fridge like they use fridge.  Take readings when you remember to take readings.

Annualized
Performance
??? kwh            DOE official energy usage. We never could find the official energy spec.
560 kwh            Pre-test un-insulated in tight fridge nook. Nook ½” wider than fridge. (80 hours)
460 - 480 kwh    Pre-test un-insulated removed from nook. Plenty of ventilation
403 kwh            1” insulation applied to left side, right side and top ONLY (147 hours)
346 kwh            1” applied to all front, edges of door, 2” applied to back (274 hours)
335 kwh            Re-test (176 hours)
354 kwh            Re-test with additional 1” added to right, left and top of freezer, but not fridge. (240 hours) WORSE!!  WHY WORSE?
Next Test if there's time:  Improved door seal, and inner buffer panels slowing the escape of air when the door opens.

Personal Goal   <300 kwh.  Got close several times, but the auto-defrost heaters always came on to spoil our progress. 
We did average <300 kwh for periods of as much as 17 hours, and have gone as long as 27 hours averaging a usage of 305 kwh.  We also discovered that with a reset of the test by shutting off and turning on the fridge CAN set the stage for a long run of inefficiency.  There was certain randomness to the fridge's efficiency based on how the fridge was shut off and turned back on.  Very fast, quick "off" then "on" was worse than an 10 second shut down.  Who knows why?

This is a 25% to 30% efficiency improvement using the dumbest technology on the shelf, foam and tape. Imagine if the insulation were done in a factory without seams and if engineers who actually knew what they were doing were involved. 

It get’s better. There are 6,600 refrigerators listed in the California Energy Commission database of refrigerators which can be sold in California (it's a subset of the DOE list). When comparing the ugly but useful Volumetric Efficiency of those 6600 to my now pink "Helly Kitty" fridge:

Volumetric Efficiency = (Official DOE energy usage for each unit) divided by (total official internal volume (fridge + freezer total)

All of the 6600 units have a much worse efficiency than the pink 11 year old “Hello Kitty” fridge in my dining room with 1" of extra foam.

Note: Per the DOE test spec, those 6600 were tested in a controlled environment with a 90F ambient temperature following test procedure which requires the doors to be opened and closed and the freezer loaded or unloaded. 
We expected the tiny Sunfrost brand to perform better, but they were not listed on the Calif. list.

Manufacturers say the market does not allow for additional insulation and the loss of internal storage space. Really? 
There are 6,600 models but no demand for just 3 or 4 super-insulated refrigerators?  Nothing for the crunchy folks, or off the grid customers willing to give up space, OR the millions of homes, both private and public where the fridge is not installed in a space constrained location? Really?

The important point to all of this; by adding 1” of badly applied building insulation, an idiot reduced refrigerator energy usage by 30% and made it the best fridge in America. What would happen if a better grade of idiot actually designed and built the fridges correctly in the first place?  Why not do this now?