Evaporator units in walk-in coolers are such a common item to many commercial refrigeration contractors that their installation and service may sometimes be taken for granted. However, when you consider the importance of these units to your customers, you'll understand that they deserve careful attention: after all, a restaurant owner could easily have an investment of tens of thousands of dollars of food at stake in his or her walk-in.
To ensure that evaporator units work well from day one, be sure to follow the manufacturer's specifications for minimum clearance around the evaporator. This may seem like a basic point, but you might be surprised by how often we are called to service units in walk-ins that are improperly mounted and don’t have enough clearance to ensure proper air circulation. Remember when hanging evaporator units that they'll need to be serviced eventually, so it's very important to leave easy access to all parts of the unit.
Also, be sure to check the evaporator's superheat to ensure it's within the manufacturer's specs. Again, this is an often-overlooked, yet vital step.
When piping refrigeration lines that will supply the unit, be sure to allow adequate room for a good solid horizontal mount for the TXV bulb, typically at the "5 o’clock" position on the line.
When piping the drain line, install the line with plenty of slope — typically ¼-in. of slope per foot of line, and mount it securely to the wall. Clean outs and unions may not be required, but they are very helpful. Remember that heated and insulated drain lines are a must for walk-in freezers.
Finally, seal all the penetrations from the refrigerant lines to keep moisture and warm air out of the walk-in cooler, and your unit's nice cold air in. Then, treat yourself to dinner at the restaurant to celebrate a job well done.
Danny Essary is director of service, Almcoe Refrigeration, Dallas, TX. The company is Contracting Business.com magazine's 2009 Commercial Refrigeration Contractor of the Year. Essary can be reached at 214/381-2113 ext. 106, or by e-mail, at firstname.lastname@example.org.