Air Conditioning Systems for Mushroom Cultivation: Choosing the Right Sensors Is Crucial

When cultivating edible mushrooms, certain climatic conditions must be observed in order to ensure a maximum yield of the highest quality. From compost preparation through the growth phase to harvesting the mushrooms, it is important to ensure the optimum temperature, humidity and CO2 levels. The challenge for mushroom growers and system managers is to measure and control these climate parameters as precisely as possible. The demands on the technology required for this are high and need to be considered right from the outset.

Precision Air Conditioning Creates Natural Conditions

Conditions which only exist in nature in autumn must be ensured all year round with the help of air-conditioning systems: optimal temperature and humidity conditions and the right CO2 concentration for mushroom growth. The individual components of an air conditioning and humidification system, such as humidifiers or measuring devices/data loggers for monitoring temperature, humidity and CO2 therefore need to be closely examined. The challenge: in mushroom cultivation, the technology has to cope with particularly high levels of humidity and the released fungal spores.

The Individual Phases of Mushroom Production

Ensuring mushroom growth indoors means reproducing the natural growth conditions as accurately as possible. The requirements for an air-conditioning system in mushroom cultivation are therefore driven by the individual phases of the growth process.

Phase 1: Compost Preparation and Spawning – Constant Temperature, High Humidity and CO2 Concentration

Fresh compost is the basis for mushroom cultivation. The mushroom threads (mycelium) are spread on it and completely penetrate the compost within 2-3 weeks. In this phase the conditions must be very humid, stuffy and dark.

  • Phases of mushroom production

Phase 2: Mushroom Bed Arrangement and Initiation – Gradual Lowering of Temperature

In the next step of industrial mushroom cultivation, the matured compost is spread onto mushroom beds in special growing cells. This is followed by a precisely defined process, which begins with keeping the temperature constant and a regular supply of light and air. Then the mushroom bed is supplied with water for several days and the humidity is increased to up to 100 % RH by gradually reducing the temperature. This causes the mycelium to begin to contract and form small buds from which the mushrooms develop.

 

  • In this phase, temperature, humidity and CO2 concentration have a decisive influence on the growth of the fungi.
    If the measurement data are faulty, this impacts on the entire harvest.

 

Phase 3: Growth and Harvest – Keeping Conditions Constant

In the growth phase up to harvesting, the temperature, humidity and CO2 concentration are kept constant for a maximum of seven days. Within one week the mushrooms reach the ideal size of 3 cm (1.2 inch) for harvesting.

Measuring Humidity, Temperature and CO2 in Mushroom Cultivation

During these individual phases, the right kind of climate control is crucial for the success of mushroom cultivation. The sensors used play a crucial role here. They need to measure the temperature, humidity and CO2 concentration accurately and reliably in a particularly demanding environment. Any undetected deviation, or inaccurate measurement results, impact on the quality of the mushrooms and cost money.

To choose suitable sensors, it makes sense to define the requirements precisely, taking into account the specific environmental conditions.

Mushrooms Like Things Moist and Dirty – Sensors Don’t

Optimum environmental conditions are required for the best possible mushroom growth. The constantly high humidity and the contamination by the released spores pose a particular challenge for the measurement technology.

 

  • Condensation and condensation-related deposits on the sensitive sensing elements can impair the measuring performance and lead to corrosion.
  • The spores released by the fruit body with a size of 3-15 μm settle in the whole system. The mycelium (fungal threads) formed here cover the surfaces and can lead to false readings and thus to the loss of the entire harvest.

 

Measurement technology for industrial mushroom production has to be very tough. This means that the decision as to which sensors to integrate into the mushroom growing climate control system must be taken with particular care.