Featured Research

from universities, journals, and other organizations

Using Liquid To Cool Grocery Cases Saves Energy, Better For Environment

Date:
April 9, 1998
Source:
University Of Illinois At Urbana-Champaign
Summary:
Refrigerants leaking from systems that chill supermarket display cases are a leading source of environmental pollution. Recent tests by a team of University of Illinois researchers indicate that an alternate method of refrigeration can reduce leakage and save money.

CHAMPAIGN, Ill. -- Refrigerants leaking from systems that chill supermarket display cases are a leading source of environmental pollution. Recent tests by a team of University of Illinois researchers indicate that an alternate method of refrigeration can reduce leakage and save money.

Related Articles


"There are approximately 30,000 large supermarkets in the United States, and the typical supermarket leaks about 1,500 pounds of refrigerants annually," said Predrag Hrnjak, a professor of mechanical and industrial engineering and a researcher at the university's air conditioning and refrigeration center. "This is a huge problem. In fact, supermarkets are second only to automotive air-conditioning systems in polluting the atmosphere with refrigerants."

One potential solution is to replace the high-pressure gas used in conventional refrigeration systems with a low-pressure liquid, Hrnjak said. "Circulating a liquid refrigerant a technique called secondary cooling can increase energy efficiency, reduce refrigerant leakage, and utilize a centralized refrigeration unit that is more reliable and less expensive to operate."

While thousands of European supermarkets have switched to the secondary cooling technology, the idea has been slow to catch on in other parts of the world. In the United States, for example, about 100 supermarkets have been converted.

One reason for the slow acceptance, Hrnjak said, is that "few tests have been performed to determine which system is actually more efficient. Nor do we know which fluid is the best one to use."

To answer such questions, Hrnjak, research engineer Yanhui Mao and graduate research assistant Wilson Terrell Jr., compared the performance of a typical supermarket display case operating with a conventional refrigerant (R404A) and with two different secondary coolants (potassium formate and potassium acetate). The researchers placed a display case, filled with simulated food packages, in an environmental chamber and monitored package temperatures as a function of refrigerant temperature.

"We found that the display case performed better with potassium formate as a secondary coolant than with the conventional refrigerant," Hrnjak said. "Our tests showed that the same product temperature could be achieved with a higher operating temperature of secondary coolant.

"For example, to maintain frozen foods at the proper temperature, the R404A refrigerant must have an inlet temperature of -32.5 degrees Centigrade," Hrnjak said. "The same product temperature, however, could be achieved with potassium formate at an inlet temperature of only -26.5 degrees Centigrade. This is a significant difference in temperature and the amount of refrigeration required."

The preliminary results "indicate that secondary cooling is a cost-effective and energy-efficient alternative to conventional refrigeration. And it's better for the environment," Hrnjak said.

The researchers presented their findings at the International Institute for Refrigeration conference, held in Cambridge, England, March 29-April 1.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Using Liquid To Cool Grocery Cases Saves Energy, Better For Environment." ScienceDaily. ScienceDaily, 9 April 1998. <www.sciencedaily.com/releases/1998/04/980409080701.htm>.
University Of Illinois At Urbana-Champaign. (1998, April 9). Using Liquid To Cool Grocery Cases Saves Energy, Better For Environment. ScienceDaily. Retrieved March 29, 2015 from www.sciencedaily.com/releases/1998/04/980409080701.htm
University Of Illinois At Urbana-Champaign. "Using Liquid To Cool Grocery Cases Saves Energy, Better For Environment." ScienceDaily. www.sciencedaily.com/releases/1998/04/980409080701.htm (accessed March 29, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, March 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Inspectors Found Faulty Work Before NYC Blast

Inspectors Found Faulty Work Before NYC Blast

AP (Mar. 27, 2015) An hour before an apparent gas explosion sent flames soaring and debris flying at a Manhattan apartment building, injuring 19 people, utility company inspectors decided the work being done there was faulty. (March 27) Video provided by AP
Powered by NewsLook.com
Facebook Building Plane-Sized Drones For Global Internet

Facebook Building Plane-Sized Drones For Global Internet

Newsy (Mar. 27, 2015) Facebook on Thursday revealed more details about its Internet-connected drone project. The drone is bigger than a 737, but lighter than a car. Video provided by Newsy
Powered by NewsLook.com
Robot Returns from International Space Station and Sets Two Guinness World Records

Robot Returns from International Space Station and Sets Two Guinness World Records

Reuters - Light News Video Online (Mar. 27, 2015) The companion robot "Kirobo" returns to earth from the International Space Station and sets two Guinness World Records. Sharon Reich reports. Video provided by Reuters
Powered by NewsLook.com
Residents Witness Building Explosion, Collapse

Residents Witness Building Explosion, Collapse

AP (Mar. 26, 2015) Witnesses recount the sites and sounds of a massive explosion and subsequent building collapse in the heart of Manhattan&apos;s trendy East Village on Thursday. (March 26) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins