Determining the performance of air conditioners requires testing on specific calorimeters. POLO designs and applies calibrated type calorimeters for testing air conditioners as defined in NBR 5858. These calorimeters enable the performance measurement of air conditioners with capacities between 7000 and 60000 BTU / h for window or Split The calorimeters in question consist of two independent environments for the simultaneous evaluation of the performance of the evaporator unit and the condensing unit. In each of them it is possible to control the temperature and the relative humidity of the air independently. The air speed is adjusted according to the standard settings. Calorimeter design includes electrical installation and signal acquisition design. Software for the acquisition of signals can also be developed according to the needs of the client company. The measuring sections for evaluating the performance of air conditioners are also developed and tested in accordance with the requirements proposed for the test. After assembly, the calorimeter is calibrated and the operating conditions are adjusted and verified to meet the requirements of standard NBR 5858.