I must confess. I used to work in a factory that made environmental control units for computer rooms. They heated, cooled, de-humidified, humidified and atomised any dust, all in one unit. The evaporators were made in the factory and all pipework was brazed on the line. My job was filling and sniffing, but it was done with a charging station. We had very few units fail in the factory and they all worked perfectly when they arrived in the USA. We lost the contract to a Chinese plant.