Sensible Cooling

The removal of heat from the air while maintaining the same level of humidity is the definition of sensible cooling. On the psychrometric chart (on the right), the progression of the cooling process may be seen as a horizontal line moving from right to left. The humidity ratio (W) and the temperature at which the dew point (DP) is measured in the air do not shift as a result of this process. The wet bulb temperature (Twb), relative humidity (percent RH), specific volume (v), and enthalpy (h) all go through shifts in value. Because there is no moisture removal during zone sensible cooling, the cooling coil always works in a dry environment. This is one of the most distinguishing features of this type of cooling. In order to achieve this goal, the temperature of the chilled water that is provided to the coils needs to be maintained at or above the dew point for the room. This is commonly referred to as medium temperature chilled water, despite the fact that it is warmer than the chilled water that is utilised in conventional HVAC systems.

Sensible Cooling Load

The term “sensible cooling load” refers to one of the two different kinds of cooling loads that together constitute the entirety of the “design cooling load.” The quantity of heat energy that must be taken from a building in order to keep the internal temperature at the design temperature, even when the exterior conditions are at their worst, is referred to as the design cooling load. Let’s imagine you reside in Florida, where the temperature is 98 degrees Fahrenheit (37 degrees Celsius), and the humidity is at one hundred percent. These conditions are rather intolerable, and they can place a burden on HVAC systems that are working to keep the temperature at 77 degrees Fahrenheit (25 degrees Celsius) while reducing the humidity as much as possible. Instead of actively chilling the space itself, this method involves redistributing the heat energy that is already present.

There are several different aspects that contribute to the total sensible cooling load. There are many different types of openings, including glass windows and doors, sunlight penetrating the building, exterior walls, partitions, floors over open crawl spaces, air infiltration between cracks, ceilings under an attic, people occupying the building, equipment and appliances being used, lights, different types of roofing, ductwork, and insulation throughout the home.

The exterior temperature and humidity, the size of your home, and the direction your property faces are the only ones of these characteristics that are beyond your control. The sun’s rays will bring in more heat into your home if it faces south or west. This is because these directions receive the most sunlight. The following are examples of factors that are under your control: air leaks, degrees of insulation, heat infiltration through windows, and heat-producing appliances located within your home. It is possible to stop air from escaping through cracks and leaks, add more insulation, and schedule the use of appliances that produce heat for the evening hours.

Sensible Heat

Sensible heat, as its name suggests, refers to the type of heat that we are capable of feeling or sensing (sense-able). The temperature is typically used as the unit of measurement.

The temperature is higher when there is a greater amount of perceptible heat.

To put it another way, the bigger the amount of sensible heat present in a room, the greater the amount of sensible cooling capacity that is required for air conditioners to successfully chill the room.

As a result, air conditioners are required to have sensible cooling capacity, however this is not necessarily the case for latent cooling capacity.

Latent Heat

Hidden is another word that can be used interchangeably with latent. Because of this, one may also refer to latent heat as concealed heat. It is the heat that we are unable to feel or perceive, as the name of the phenomenon suggests.

When we bring a bowl of water to a boil, the temperature of the water stops rising after that point on the thermometer. This is due to the fact that heat energy is required to transform water from its liquid state into its gaseous state, and the heat energy in question is latent heat.

On the other hand, if we wish to remove moisture from the air, which would involve converting the water that is currently in the form of a gas back into the form of a liquid, we will need to remove a sufficient amount of the latent heat that is given off by the water.

Conclusion

The sensible cooling load is a measurement of the amount of energy that must be removed from something, like the air inside of a building, for example, in order to maintain a certain temperature, regardless of the temperature outside. This can be done in order to keep a comfortable temperature inside the building. When determining the capacity of a cooling system, it is necessary to take into account the amount of cooling load.

During the sensible cooling process, the temperature of the dry bulb (DB) and the temperature of the wet bulb (WB) of the air both drop, but the temperature of the latent heat of the air and the temperature of the dew point (DP) of the air do not change. In most cases, the sensible cooling process consists of moving the air over the coil in order to achieve the desired temperature.