Freeze Time and Ambient Temperature

Freeze Time and Ambient Temperature

Ever wondered why the performance of your Klaris machine undergoes intriguing shifts with the changing seasons? There is a perfectly logical explanation behind it and we're here to break it down for you. Let’s dig in!

Heat pumps are devices designed to transfer energy from cooler to warmer spaces. They play a vital role in a multitude of applications such as air conditioning, dehumidifiers, refrigerators, and yes, even ice makers. While refrigeration stands as the common heat pump architecture in today's ice makers, with impressive efficiency, it comes with drawbacks - its large size, considerable noise output, and the utilization of ozone-depleting and flammable chemicals. On the other hand, we have the innovative thermoelectric technology, harnessed by the Klaris machine. Although less efficient, this cutting-edge approach offers unmatched advantages. Its compact design grants a smaller footprint and reduced weight, while eliminating the need for harmful chemicals altogether.

How it works

A thermoelectric is fed power (Q1) and with that power it can pump energy (Q2) across itself using the Peltier effect to form a cold and hot sideThe power fed (Q1) is always greater than the power pumped (Q2). For the system to work properly, Q1 & Q2 must both be removed from the hot side of the thermoelectricIf the energy is not removed from the hot side, the heat pumping capability will go to zero. This energy dissipation is normally done with a heatsink (thermal conduction) and a fan (thermal convection).

Thermal Conduction

Thermal Conduction is a process by which heat is transferred from a hot side to a cold side of an object. Materials like aluminum and copper transfer heat well while plastics do not. The larger the temperature differential between the hot and cold side of the object, the more energy that can be pumped. This is represented in the equation Q = -k*dT where Q is energy moved, k is the thermal conductivity of the object and dT is the temperature difference between the hot and cold sides. In the Klaris device, a heatsink made up of heat pipes and aluminum fins is used to transfer energy to a larger surface area away from the thermoelectric device.

Thermal Convection

Thermal Convection uses the movement of a fluid to transfer heat from one place to another. Thermal convection is calculated using the equation Q = h*A*dT where h is the heat transfer coefficient, A is the surface area of the material and dT is the difference in temperature between the surface and the fluid. In the Klaris system, a fan is used to blow room temperature air across the heatsink conducting energy away from the hot side of the TEC.


PC: Fan and Heat sink 

Looking at the principles of thermal conduction and convection, there are a few levers that can be pulled to increase the energy removed from a system including the fan speed, heat sink surface area, heatsink thermal conductivity and/or ambient temperature. Due to product constraints (ie. Size, weight, noise and cost), Klaris has been optimized to the best of its ability. This leaves just the ambient environment as the main lever for improved performance.

As the seasons shift, it is not uncommon for the performance of the machine to fluctuate responding to the ever-changing ambient air temperature. As warmth covers the surroundings, the machine's ability to extract energy from the heatsink encounters a subtle shift, ultimately influencing the energy transported through the thermoelectric system. Consequently, this dance of thermal dynamics manifests as extended freeze times, adapting to the rhythm of the seasons. 


Average Freeze Times (hr)

Assumed Ambient (F) 













Some recommendations to improve freeze times:

  • Move machine to a cooler location (<72F). 
  • No direct sunlight. 
  • Avoid drafty and/or small rooms. 
  • Refrigerate water before placing into the machine.

Understanding the principles of thermal conduction and convection highlights the significance of ambient environment especially when it comes to your machine. Implement some of the recommendations above which will ensure you a delightful ice-making experience throughout the year. Thank you for reading and stay tuned for our next blog!!

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