Energysmart Greenhouses with Confluent Jets

Climate-controlled greenhouses offer the ability to control indoor conditions such as temperature and humidity to optimize yields, which can be increased up to 10-20 times, compared to traditional outdoor cultivation. However, the current high energy consumption to maintain these conditions poses a challenge for environmentally and economically sustainable cultivation. New opportunities for energy-efficient climate control in greenhouses have emerged through the use of Confluent Jet (CJ) technology such as Heating, Ventilation, & Air Conditioning (HVAC) systems.

Confluent Jets

The phenomenon of C J occurs when multiple interacting jets are emitted from a set of round nozzles that are positioned close to each other. Initially, the jets move side by side and then coalesce into a uniform beam at a certain distance downstream from the diffuser. The system is based on matrices of integrating and interacting round jets that come from nozzles in a supply air diffuser in the same level and flow in a parallel direction. After a certain distance, these rays unite to form a uniform jet stream. The behaviour of the rays means that they are not affected by other air currents in the greenhouse. The combined power of these confluent jets is preserved more efficiently than that of a single large jet, resulting in lower energy consumption, longer throw length, and thus lower operating costs. CJ technology also offers an all-in-one solution for regulating operational air temperature, airflow velocity, air turbulence intensity, relative humidity, and CO2 levels.

Purpose of the project

Seeds for Sustainability: Energy-smart HVAC systems in greenhouses with Confluent Jets aim to investigate and validate the use of CJ technology in greenhouse environments to reduce energy use and increase the profitability of crop production in greenhouses year-round. By addressing scientific knowledge gaps around energy-smart solutions for greenhouse cultivation and develop energy-efficient greenhouse designs that integrate CJ technology, the project aims to maximize food production per land area while reducing water consumption, energy use and CO2 emissions.

The purpose of the project is fulfilled using a combination of methods:

1. Field-based measurements of CJ in greenhouses
2. Simulations with computational fluid dynamics (CFD)
3. Energy simulations together with techno-economic optimization

Factors such as climate, different types of greenhouse constructions and crop types, will be taken into account to develop insights and solutions for the practical application of CJ technology.

Result

By working closely with external actors from industry and research institutions, the project aims to provide solutions that meet the diverse needs of both small and large-scale greenhouse growers, who face challenges of high energy use and high costs for cultivation all year round.