Open top display cooler - energy loss

In summary, the conversation discusses an energy analysis in a supermarket and the challenge of calculating energy usage for open top display coolers. The speaker mentions using a program called Coolpack which identifies air infiltration as the main issue. The conversation also suggests various ideas for measuring and reducing energy usage in open front supermarket display refrigerators. The conversation ends with a recommendation to use a clamp on ammeter and a link to an article discussing the physics of grocery store display cases.
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Homework Statement


I am working on a energy analysis in a supermarket. There is some open top display coolers, which is using a lot of energy - I don't have the opportunity to check excatly how much energy they use, so I have to calculate it. I don't have problems in calculating it when it is closed, but I have no clue on how to do it, when there is a "open 'wall'".
I know there are some uncertain variables, temperature, humidity and ventilation. But I'm going to make them constant:
Temp outside 22 degr C, humidity outside 50%, temp in cooler 2 degr C, humidity in cooler 85%.

I have been using the program called Coolpack (EESCooltools), and it is telling me, that my problem is the air infiltration! And I do agree :)

Homework Equations


The heat loss caused by infiltration can be calculated as

Hi = cp ρ n V (ti - to) (8)

where

Hi = heat loss infiltration (W)

cp = specific heat capacity of air (J/kg/K)

ρ = density of air (kg/m3)

n = number of air shifts, how many times the air is replaced in the room per second (1/s) (0.5 1/hr = 1.4 10-4 1/s as a rule of thumb)

V = volume of room (m3)

ti = inside air temperature (oC)

to = outside air temperature (oC)
Sources ^^ = http://www.engineeringtoolbox.com/heat-loss-buildings-d_113.html

Would it be possible to measure the windspeed in the cooler with a anemometer. Then check the speed every 3 cm from the products to the top, and so multiply it by the cross-section and breadth and take the average?My other idea is to measure the temperature 10 cm above the products and then: 1) Create a frame of flamingo, cover it with a lid of acrylic 2) Measure the temperature here and then find the difference between an open and a closed.All ideas will be appreciated, thanks in advance.
 
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  • #2
A google image search, "supermarket open display refrigerator"

https://www.google.com/search?hl=en...&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi

Came up with,

http://kaixue.en.alibaba.com/product/489461622-212510680/supermarket_open_display_cooler_showcase.html

Which gives size and power usage half way down the link above.

What you need is a clamp on ammeter with a time analyzer if such a tool exists.

See also google search,

https://www.google.com/webhp?hl=en#...w.,cf.osb&fp=577f5846657ec0b7&biw=734&bih=439

which turns up,

http://www.washington.edu/news/arti...of-grocery-store-display-cases-to-save-energy
 
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FAQ: Open top display cooler - energy loss

1. How does an open top display cooler contribute to energy loss?

Open top display coolers are designed for easy access to products, but this also means that the cold air inside the cooler can escape more easily. This results in a constant need for the cooler to work harder to maintain the desired temperature, leading to increased energy consumption and higher electricity bills.

2. Can energy loss be reduced in open top display coolers?

Yes, there are several ways to reduce energy loss in open top display coolers. One option is to install energy-efficient LED lighting instead of traditional fluorescent lights. Another option is to use insulated glass doors or curtains to cover the open top when the cooler is not in use. Regular maintenance and cleaning of the cooler's components can also help optimize its energy efficiency.

3. How does the temperature of the surrounding environment affect energy loss in an open top display cooler?

The temperature of the surrounding environment can have a significant impact on energy loss in an open top display cooler. If the cooler is placed in a hot or humid environment, its compressor will have to work harder to maintain the desired temperature, resulting in increased energy consumption. It is important to consider the location of the cooler and its surroundings when trying to reduce energy loss.

4. Are there any regulations or standards for energy efficiency in open top display coolers?

Yes, there are regulations and standards in place for energy efficiency in open top display coolers. In the United States, the Department of Energy has set standards for energy consumption in commercial refrigeration equipment, including open top display coolers. Additionally, many countries have their own energy efficiency regulations that manufacturers must comply with.

5. How can businesses balance the need for energy efficiency with the need for product visibility in open top display coolers?

It is possible to strike a balance between energy efficiency and product visibility in open top display coolers. As mentioned earlier, using LED lighting and insulated glass doors or curtains can help reduce energy loss while still allowing customers to see the products inside. It is also important to regularly assess and adjust the temperature settings to ensure they are optimized for both efficiency and product preservation.

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