The formation of condensation in the interior of the motorhome as well as in the garage is moisture in the form of steam that is present in the room air. Warm air can absorb more moisture than cold air. If the warm room air cools down, the water condenses and precipitates as visible water on cooler surfaces (state of the art).
That means: Condensation describes the process when the moisture in the air turns into visible water droplets. Cold air can absorb less water damp than warm air. So condensation always occurs when the air cools down.
The formation of condensation can be avoided and reduced if the relative humidity remains as low as possible. This requires a balanced combination of temperature and humidity at every point in the room, i.e. adequate ventilation and sufficient heating must be provided.