Redesign improves energy efficiency of supermarket cold food cases

[DainBramaged]

We’ve all been there, standing in the supermarket's cold foods aisle, trying to decipher the fruit juice cocktails (cranberry-orange-pineapple? banana-grape-apple?) and catching a chill during the process. The open-air refrigerated display cases are awfully convenient for reading the (complicated) labels, since they've got no glass to fog up. But the air that is making you cold isn’t keeping the food cold, so this represents a loss when energy is required to cool replacement (warmer) air. Up to three-quarters of the energy for cooling in these cases is used to make up for warm air mixing into the cold.

Since open-front formats make up about 60 percent of all refrigerated display cases, this represents a significant amount of energy. To try and reduce some of this wasted energy, a team of engineers at the University of Washington and Kettering University led by Mazyar Amin used physics to improve the designs of open-front refrigerator cases (it was his thesis project). In a recent paper in Applied Thermal Engineering, they show that energy usage can be reduced by 10 to 15 percent with simple modifications—and if these changes are made nationwide, hundreds of millions of dollars in energy costs could be saved.

Refrigerated display cases in supermarkets are ubiquitous, practically invisible pieces of technology—but use about 36 percent of a typical supermarket’s energy. On average, US grocery stores use about 194 kWh per m2 on refrigeration. This works out to 828,000 kWh in a year (and $87,600 based on an average cost of energy of $0.1058 per kWh) for a store of the median national size. With over 30,000 larger supermarkets in the US, that’s almost $3 billion on refrigeration alone. Obviously, even a small reduction in energy usage means a huge savings nationwide (and possibly thousands per store).

Open-air refrigerator cases actually use something called an air curtain to help keep the cold air in and the warm air out. This is a jet of cold air blown down across the opening as a sort of shield—these significantly decrease the amount of warm air mixing in compared to a completely open case, but they aren’t perfect. In fact, the air curtain can actually capture some warm air (entrainment), which you want to minimize. The engineers showed that, by changing a couple of controlling factors, you can do just that.

http://arstechnica.com/science/news/2011/10/redesign-improves-energy-efficiency-of-supermarket-cold-food-cases.ars

[flvegan]

1. Now, how to "redesign" the morons who stand with the doors open

trying to decide what to grab? Yeah, cuz that glass isn't see-through. Oh, wait...

[DainBramaged]

2. Baby steps, baby steps

These industries are resistant to change unless you show them the money. The problem is retrofitting a myriad number of case designs to fix the immediate use problem.

[flvegan]

4. And I do applaud

the subject of your OP. I was your first Rec. I just oft let real life idiots rule how I post here.

Good to see you.

[DainBramaged]

6. I'm not chest-thumping about wall street, this will sink or go to zero

I'm posting less and less, the real-life idiots rule now. If it's American made, they don't give a shit. And they wonder why we're the 99%.


Be well.

[flvegan]

7. Hey, just for you

I saw my first (and probably only, ever) CTS-V wagon on the HF Bridge around 3 weeks ago. License tag "V WAGON" and driven by a woman loving every minute of it.

WANT! WANT WANT WANT WANT WANT!! Holy $hit y'all got that one right.

[FarCenter]

3. Always buy milk at places where the refrigerator cases have doors

If you want it to last after you get it home.

[texanwitch]

5. At Target and Krogers the freezer lights turn on when you walk by.

So cool.

[Ikonoklast]

8. Those are DNA scanners.

They are making replicas of each of their customers, one little bit at a time.

Then, one day when you aren't looking, they grab you off the store floor, sedate you, put your clothes on the cloned replacement and send them home.

They then take you back to the meat cooler, and...did you ever wonder where Cure 81 hams came from?

[Poll_Blind]

10. .

:rofl:

:thumbsup:

PB

[texanwitch]

11. That is why Cure 81 tastes so good.

Pork, the other white meat.:hide:

[DocMac]

9. ALL stores think Sq. footage and placement.

Thats what they do. Why don't they think "under" the floor?

You could have solar power to generate enough power to sink a display down into the cooler and back up.

Visual displays could desciribe what is below and when you decide to buy that item, just choose that section and it comes up and get what you want.

Just a thought.

[KamaAina]

12. Believe it or not, this was used as an excuse for why corner stores don't carry produce

at a recent healthcare conference. Supposedly the cases are such energy hogs that the poor, put-upon store owners can't cope. Yet they use them for beer, energy drinks, et al. without batting an eyelash. :eyes: