Greenhouse humidity control is unlike any other industrial setting. This is due to the unique relationship between the plants and the air. Exposure to differing conditions throughout the day and over different seasons further differentiates the two.
Humidity control in greenhouses and indoor growing facilities is a necessity. Untreated humidity, in such settings, leads to major problems and inefficiencies. Crops grow slower, smaller and in lower quality when they experience suboptimal conditions.
Unchecked humidity will cause condensation inside any facility. The presence of this free water leads to the development of diseases such as botrytis and downy mildew, which can rapidly destroy large amounts of vegetables, cannabis or any other crop.
What is Humidity?
To understand the difference between agricultural and industrial humidity control, it’s important to understand what humidity is.
In short, humidity is the amount of water vapor in the air. In most cases, experts present humidity as relative humidity. This is the amount of water vapor in the air, as a percentage of the maximum water vapor the air can hold.
The most important aspect of relative humidity is also the least intuitive part of it. The colder air gets, the less water vapor it can hold. So there are two main factors affecting relative humidity – the absolute amount of water vapor and the air’s temperature.
Once relative humidity reaches 100%, either by moisture building up, or by the air cooling down, water starts to condense. This is known as the dewpoint and is exactly what growers try to avoid.
How Do Plants Generate Humidity?
One of the main differences between agriculture and industry, is that the crops themselves constantly emit water vapor.
Plants require water to perform the most basic physical processes. In most settings, the water will be provided through the ground. The plants take in water through the roots and emit water vapor from their leaves. Crops transpire as much as 90% of the irrigation water this way, constantly pushing the relative humidity upwards.
How Greenhouse Humidity Control Differs from Industrial Dehumidification?
Standardization is the leading principle behind industrial manufacturing. Most processes happen in highly controlled environments, in which climate conditions are strictly regulated and maintained. The processes usually expect and account for any water vapor or heat emissions.
Greenhouses, on the other hand, cannot apply the same level of standardization. Most greenhouse operations will experience fluctuating conditions. Outdoor temperature and humidity have a great impact on the conditions inside. The conditions differ throughout the day and over different seasons, making it impossible to account for changes beforehand. Rather, greenhouse growing is based on agronomical research, predictions and real-time responses to differing conditions.
Plants are living organisms. As such, their physiological behavior changes in reaction to their environment. The main factors affecting the rate of transpiration include temperature, lighting and radiation, plant size, and foliage density. All of which change constantly. These fluctuations in temperature and transpiration rates, throughout the day and night, lead to everchanging relative humidity levels.
One of the most common overlooked aspects when comparing dehumidification systems, is the expected or desired conditions in the facility. Many dehumidification manufacturers present their water extraction rates at a temperature of around 80oF. While most greenhouses aim to operate at lower temperatures, around 64oF. As colder air holds less water vapor, the extraction rates are much lower. Growers should keep this in mind when considering humidity control options.
Get Better Results with Dedicated Greenhouse Humidity Control
While most humidity control systems out there still cater to industrial needs, many newer manufacturers specialize in agriculture alone.
Dedicated dehumidifiers for agriculture are designed specifically for the conditions and challenges faced in greenhouses, glasshouses and indoor growing facilities. Manufacturers such as DryGair come from a background of greenhouse research and are designed and tested to operate specifically in ecosystems associated with crop cultivation.
When it comes to greenhouse growing, humidity control requires more than a dehumidification unit. It takes real know-how and understanding to reliably eliminate humidity problems, as well as maintaining efficient energy consumption in the process.
Working with companies that specialize in agriculture provides added value to growers. The ability to receive reliable consultation, based specifically on your growing space and climate conditions, can make a huge difference in crop quality and growth, as well as reduce operational costs.