Operating Conditions for the AMARU Freeze Dryer

This topic actually makes up a large part of the entire AMARU Maintenance category on this blog. Every device requires certain operating conditions, and how well these conditions are met will also affect how often the user — or even our service team — needs to intervene.

So why not take a closer look at this subject?

Temperature

We have already written quite extensively about the temperature required for operating the AMARU freeze dryer in the article Temperature Matters.

AMARU requires an ambient operating temperature between 15°C and 25°C. If the temperature is lower, it has a negative effect on both the electronic components and, more importantly, the rubber parts, such as the chamber seal and internal vacuum connectors. Naturally, it also affects the oil in the vacuum pump.

On the other hand, when the temperature rises towards 30°C and above, even pressure measurement can be affected, which may influence the final result of the food drying process.

Repeated starts at temperatures below 15°C may also damage the refrigeration unit.

Humidity

The maximum permitted humidity for operation is 60% without condensation.

Higher humidity can have a negative impact, especially on the electronic components inside the freeze dryer. In addition, dried food will start absorbing moisture again quickly after being removed from the freeze dryer. For this reason, it is advisable to keep the room humidity at the usual level of 40–50%.

In other words, if stalactites are growing from the ceiling in the intended room, it is definitely not a suitable place to operate a freeze dryer — even if it is not hot there.

Ventilated Space

Room ventilation is closely connected to temperature. The AMARU freeze dryer cannot simply be placed in a tiny 2 × 2 metre storage room and expected to perform well.

Based on our own experience, a room of at least 10 m² is ideal. After all, you will also need some handling space, and running two rooms away to wash the product trays is not exactly practical.

At the same time, the room must be properly ventilated — either by a window that can air the room sufficiently, or by a dedicated ventilation system.

Illustration: minimum space required for operating the AMARU freeze dryer

Stable Power Supply

AMARU only requires a standard 230 V socket, but it must have its own 16 A circuit breaker.

This is important to keep in mind when purchasing a stacked AMARU setup, where each unit will require its own 16 A circuit breaker. It is also advisable to have a residual-current device installed.

Another important factor is the stability of the power supply. In larger towns and cities, this is usually not a problem. However, operating AMARU in a village where voltage drops occur several times a day may lead to damage to the freeze dryer’s control unit.

An occasional power outage is not such a major issue, as AMARU is usually able to resume the process from the point where the power was interrupted.