delta T fluid elements represent the state of current technology. Whilst formerly water filled and deep frozen accumulators were known, delta T now uses special fluids made of phase change material.
The fluid filling changes in its respective temperature range from solid into liquid state. Hereby, large quantities of heat are absorbed or released. This causes a very slow temperature rise at phase change temperature. delta T now have fluids for temperature ranges from -50°C to +37°C and offers many accu casing available.
The design of the cases are of delta T property.