2021 RETA Breeze May-June

MICROBIAL HAVEN TO SAFE HAVEN

RoomTemperature is the First Key Room temperature is, perhaps, the most obvious component of temperature and condensation problems. To understand how room temperature creates issues within an area in your facility, begin by cataloguing a history of the temperature control problems. Does it only get warm during a certain time of day? Is the temperature problem localized within the room (e.g., one area within the room is warmer than others)? Answers to these questions may point to an undersized refrigeration system. Next, look at how the room is being used. Are forklift users or others who have business in the room leaving doors open for convenience sake? You’ll also need to look at the recommended storage or process condition for the room, a factor typically set by a Quality Control (QC) or Quality Assurance (QA) department. How does the temperature of the room compare to that number? Finally, you’ll need to identify the temperature of all the surfaces within the room, identifying any cold surfaces that may promote the formation of condensation (i.e., surface temperatures that are below the dew point temperature of the air). RoomHumidity Another Likely Culprit Because it can lead to condensation, increased room humidity is the next piece of the temperature/condensation puzzle. Just like room temperature, you need to begin by understanding when the increased humidity is occurring. Is it seasonal (e.g., more condensation during the summer), or does condensation only occur at a particular time of day? Location is also important. Is there condensation throughout the room or is there condensation only on certain surfaces? To understand how the room is being affected by humidity, you must calculate the dew point temperature (see “Helpful Definitions,” page 4) of the room air at various locations and during various times

of the day. Does that dew point temperature of the air fluctuate or remain constant? You may also want to calculate the percentage of relative humidity (see “Helpful Definitions,” page 4). If surface temperatures are lower than the dew point temperature of the air, then condensation will form on those surfaces. Some typical surfaces that could be below the dew point temperature of the room air include: • Cold product transfer lines • Refrigerant or chilled water lines that are inadequately insulated • Supply air ducts/diffusers • Unit cooler casing and drain pans • Floors and door frames that connect to a colder adjoining room • Room ceilings and walls which are cold due to refrigerated supply air Surfaces that are below the dew point temperatures of the air may need to be insulated or heat traced. Sanitation is another big factor contributing to room humidity. Is the room a fog bank during the sanitation cycle? If so, this is creating saturated

room conditions, leaving all surfaces wet and requiring a longer time to dry out. You also need to determine exactly how long it takes for the room to dry out after sanitation. If the room never gets drier, then the unit coolers may not be sized properly or the extra latent heat load (see refrigeration system to handle. The Importance of Air Flow and Pressurization Room temperature and condensation issues caused by sanitation, room openings/doors and improperly insulated or heat traced pipes and equipment aren’t the only reasons why rooms inside meat plants can be at less-than-ideal conditions. Air flow and room pressurization are also important factors to consider. To understand air flow, you’ve first got to measure it. Which direction is the air flowing? How much? How fast? What are the sources of air coming into the room? Are there doors being left open? Are there exhaust fans creating areas of negative pressure? “Helpful Definitions,” page 4) being generated may be too high for the

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