Thermoelectric assemblies deliver precise thermal management

A cell culture incubator is designed to maintain a constant temperature and high humidity for the growth of tissue culture cells under a CO₂ atmosphere. Typical temperature settings range from 4 to 80°C, with relative humidity between 95-98% and CO₂ concentrations ranging from 0.3-9.9%. Historically, temperature in CO₂ incubators was controlled either by a water bath that circulated through the walls of the cabinet (water jacketed), compressor-based systems or by electric coils that gave off radiant heat. Modern units now use solid-state thermoelectric-based cooling for temperature control.

Laird's TEAs, including the AA-230 Series and AA-250 Series, offer a high Coefficient of Performance (COP) to minimise power consumption when cooling or heating CO₂ incubators. Based on a standard platform, TEAs can be customised to meet application requirements. These TEAs offer 230 and 250W of cooling power at Delta T=0°C respectively. Using impingement flow to transfer heat, the AA-230 and AA-250 Series offer dependable, compact performance by cooling objects via convection. The solid state construction requires less maintenance than standard compressor-based cooling systems.

Temperature stability is vital in CO₂ incubators, and Laird’s TEAs, driven by the SR-54 programmable microcontroller, deliver temperature stability to within ±0.15°C of the temperature set point in cooling and heating mode. With built-in monitoring and closed loop feedback control intelligence, the SR-54 temperature controller provides monitoring and alarm functionality, including identification of a problematic fan, thermoelectric module, over-temperature thermostat and temperature sensor failure -- all of which are critical to maximising CO₂ incubator uptime. The ready-to-use controller requires minimal programming out of the box and is easily attached to a TEA or system enclosure. The controller also lowers operational noise, as fans are turned off once the specified temperature has been reached inside the respective incubator column.

Active humidity control ensures short recovery times after the door has been opened and minimises vaporisation in the interior.

"Laird's compact thermoelectric assemblies have a size-to-cooling capacity ratio that offers customers a significant design advantage compared to other technologies. When combined with the SR-54 temperature controller, our cooling systems reach the temperature set-point quickly, without temperature overshoots or significant ramp down, shortening the incubation cycle time," said Anders Kottenauer, Senior Vice President of Laird's Engineered Thermal Systems Business. "Standard off-the-shelf controllers are too complex, or do not have basic alarm and control features required to operate a TEA effectively. Installing this ready-to-use SR-54 bi-polar temperature controller can save engineers hundreds of product development hours, as it has been optimised to run thermoelectric assemblies."