Hussmann CHINO CID, Installation And Operation Manual

Rev. 0508 

17

Appendix C - Field Recommendations - Refrigerated

Recommendations for field evaluating the 

performance of retail food refrigerators and hot cases

1.0  The most consistent indicator of display 

refrigerator performance is temperature of the air 

entering the product zone (Refrigerated see 

Diagram 1, Appendix A). In practical use, the 

precise determination of return air temperature 

is extremely difficult. Readings of return air 

temperatures will be variable and results will be 

inconsistent. The product temperature alone is 

not an indicator of refrigerator performance.

NOTE:  public Health will use the temperature of the product in 

determining if the refrigerator will be allowed to display 

potentially hazardous food. For the purpose of this 

evaluation, product temperature above the FDA Food 

Code 1993 temperature for potentially hazardous food 

will be the first indication that an evaluation should 

be performed. It is expected that all refrigerators will 

keep food at the FDA Food Code 1993 temperature for 

potentially hazardous food.

1.1  The following recommendations are made for the 

purpose of arriving at easily taken and understood 

data which, coupled with other observations, 

may be used to determined whether a display 

refrigerator is working as intended:

a)  INSTRUMENT - A stainless steel stem-type 

thermometer is recommended and it should 

have a dial a minimum of 1 inch internal 

diameter. A test thermometer scaled only 

in Celsius or dually scaled in Celsius and 

Fahrenheit shall be accurate to 1°C (1.8°F). 

Temperature measuring devices that are 

scaled only in Fahrenheit shall be accurate to 

°F. The thermometer should be checked for 

proper calibration. (It should read 3°F when 

the stem is immersed in an ice water bath).

b)  LOCATION - The probe or sensing element 

of the thermometer should be located in 

the airstream where the air first enters the 

display or storage area, and not more than 1 

inch away from the surface and in the center 

of the discharge opening.

c)  READING - It should first be determined 

that the refrigerator is refrigerating and has 

operated at least one hour since the end 

of the last defrost period. The thermometer 

reading should be made only after it has 

been allowed to stabilize, i.e., maintain a 

constant reading.

d)  OTHER OBSERVATIONS - Other 

observations should be made which may 

indicate operating problems, such as 

unsatisfactory product, feel/appearance.

e)  CONCLUSIONS - In the absence of any 

apparent undesirable conditions, the 

refrigerator should be judged to be operating 

properly. If it is determined that such 

condition is undesirable, i.e., the product is 

above proper temperature, checks should be 

made for the following:

1.   Has the refrigerator been loaded with warm 

product?

.   Is the product loaded beyond the “Safe Load 

Line” markers?

3.   Are the return air ducts blocked?

4.   Are the entering air ducts blocked?

5.  

Is a dumped display causing turbulent air flow and 

mixing with room air?

6.   Are spotlights or other high intensity lighting 

directed onto the product?

7.   Are there unusual draft conditions (from heating/

air-conditioning ducts, open doors, etc.)?

8.   Is there exposure to direct sunlight?

9.   Are display signs blocking or diverting airflow?

10.  Are the coils of the refrigerator iced up?

11.  Is the store ambient over 75°F, 55% RH as set 

forth in ASHRAE Standard 7 and ASHRAE 

Standard 117?

1.  Are the shelf positions, number, and size other 

than recommended by Hussmann?

13.  Is there an improper application or control 

system?

14.  Is the evaporator fan motor/blade inoperative?

15.  Is the defrost time excessive?

16.  Is the defrost termination, thermostat (if used) set 

too high?

17.  Are the refrigerant controls incorrectly adjusted?

18.  Is the air entering the condenser above design 

conditions? Are the condenser fins clear of dirt, 

dust, etc.?

19.  Is there a shortage of refrigerant?

20.  Has the equipment been modified to use 

replacements for CFC-1, CFC-50 or other 

refrigerant? If so, have the modifications been 

made in accordance with the recommendations of 

the equipment manufacturer? Is the refrigerator 

charged with the proper refrigerant and lubricant? 

Does the system use the recommended 

compressor?

Appendices (Cont'd)