Peltier Cell Help: Exploring 92W vs. 38W Efficiency

[junkfunkydude]

A while back, I purchased a 38W peltier cell on ebay. It wasn't powerful enough, so I'm looking at something along the lines of a 92W. I noticed, however that my 38W and the 92W have the same dimensions and the same number of junctions. Also, dT of the 92W is only 1 degree C above the 38W.

How is this possible?
Are the sellers providing false information?
Is one made out of a material with a higher Seebeck coefficient?
If so, will one be more efficient than the other?

Also, a general explanation as to how the different factors effect a cell would be greatly appreciated.

 

[vadslram]

I remember reading that there is some falloff of efficiency with size and that using multiple cells is a better way to go.
I got my first chip on a 80286 processor cooler (6 mhz ) and been playing with them ever since. I heard that the 08 Chrysler Sebring is coming out with heated and cooled cup holders...I can bet how they're going to do that.

 

[ravenprp]

It is not uncommon for sellers to provide false or misleading information when it comes to technical specifications of products. It is important to do thorough research and read reviews before making a purchase to ensure you are getting a reliable and accurate product.

One possible explanation for the similar dimensions and number of junctions between the 38W and 92W peltier cells is that they may be using different materials or manufacturing processes. The Seebeck coefficient, which measures the amount of voltage produced per unit temperature difference, can vary depending on the materials used. So it is possible that the 92W cell is made with a material that has a higher Seebeck coefficient, resulting in a higher power output.

However, it is not always a direct correlation between Seebeck coefficient and efficiency. Other factors such as thermal conductivity, temperature difference, and heat dissipation can also play a role in the overall efficiency of a peltier cell. Generally, a higher temperature difference and better heat dissipation can result in a more efficient cell.

In terms of how these different factors affect a peltier cell, the Seebeck effect is the principle that allows peltier cells to convert heat energy into electrical energy. When a temperature difference is applied across the junctions of the cell, it creates a voltage difference and generates an electric current. The thermal conductivity of the materials used in the cell determines how well heat can be transferred across the junctions, which affects the temperature difference and ultimately the power output. Heat dissipation is also important as excessive heat can damage the cell and reduce its efficiency.

Overall, it is important to carefully consider all the factors and specifications when purchasing a peltier cell to ensure you are getting the most efficient and reliable product for your needs.