# How the Baseboard Heating Element works

A student report prepared by Mickey T. Phagoo and David Scotti

Figure 1.

Figure 2.

The above diagram illustrates a schematic of the temperature of the water, as it leaves the boiler, enters a room and then returns to the boiler.

• The diagram shows the temperature of the water at its highest value, when the water is in the boiler.
• As the water leaves the boiler the temperature of the water begins to decrease very slowly.
• As the water enters the BHE unit in a room , there is a more dramatic loss in the heat of the water .
• And as the water exits the BHE on its way back to the boiler , the temperature of the water continues to decrease , but note the loss in temperature is not as pronounced as in the room.
• When the water reaches the boiler, the water is heated and the cycle continues again.

Figure 3.

• The above diagram show the motion of air as it circulates around a room.
• Air flow is developed  ( convection ).
• The heated BHE fins heat the surrounding cold air at the location of the BHE.
• As the air is heated, it expands and rises.
• As the warm air rises it cools and moves down to the floor .
• The cool air is then heated again and the cycle continues.

Figure 4.

The above diagram illustrates a schematic for the regions of a BHE fin, where the rate of heat transfer has varying levels of efficiency at different points on the fin.

• Region 1 shows the portion of the fin that is the most efficient . Note this region of the fin is the closest to the floor and to the pipe.
• Region 2 is the second most efficient part of the fin. Note it is also the second region  that is in direct contact with the pipe.
• Region 3 is the third most efficient part of the fin. Note this region is also the closest to the floor
• And region 4 is the least efficient part of the fin. Note this region is to the uppermost portion of the fin and is neither closest to the pipe or floor.

Figure 5.

The above diagram illustrates the temperature of the air, as it moves upwards along the fin.

• From the diagram, the lowest part of the fin( region 3  figures 4  ), depicts the temperature of the air at its lowest point.
• The temperature of the air begins to increase as it moves along the fin until it reaches the middle of the fin ( region 1  figure 4 ). Note at this point the temperature of the fin is the greatest.
• At the highest part of the fin ( region 4  figure 4 ), the temperature continues to increase but at a decreasing rate. Until the temperature levels out.

Figure 6.

The above diagram illustrates the temperature along the fin.

• At the lower region of the fin ( region 3  figure 4 ) temperature is at its lowest , but its increasing.
• At the middle portion of the fin ( region 1  figure 4. Note the fin is in direct contact with the pipe ) the temperature of the fin is at its maximum.
• At the highest part of the fin ( region 4  figure 4 ) the temperature increases at a decreasing rate and at some point begins to level out, almost asymptotically.

Figure 7.

The above diagram illustrates the fin temperature and the air temperature, as a function of the distance from the lowest part of the fin.

• As depicted by the diagrams ( Figures 7 & 4 ),the region of the fin that loses heat most efficiently is found at region 1 . This is so because of the difference between the fin temperature and the air temperature is the greatest.
• The second region that loses heat efficiently is found at region 2. Note the difference between the fin temperature and air temperature is smaller than at region 1.
• Note that the region that loses heat the least efficiently is found at region 4 . Note also that the difference between the fin temperature and air temperature is the smallest when compared to regions 1, 2 & 3.