Turnkey closed-loop greenhouses

When closed-loop greenhouses are needed

Closed-loop greenhouses suit clients who need not simply a harvest, but a reproducible environment with verified parameters. Typical applications:

• Production of virus-free planting material for potatoes, berry and fruit crops
• Meristem propagation and growing of elite seedlings
• Breeding centres working with parent lines and original seed material
• Pharmaceutical production using medicinal plants as raw material
• Research institutes and experimental stations with a phytosanitary regime
• Vertical farms and growth chambers with hydroponics or aeroponics
• CEA facilities that require repeatable conditions from cycle to cycle

All these tasks share one thing: control over pathogens, a repeatable microclimate and a sealed envelope. Without these conditions the result either cannot be verified or requires rework after every growing cycle.

Engineering systems of a sealed greenhouse

Closed-loop greenhouses differ from ordinary industrial facilities not in the frame itself, but in the set of engineering systems. The level of sealing, filtration and automation determines the cost of the facility, the time needed for certification and its suitability for a particular task.

Envelope and sealing

The frame is assembled from galvanized profiles produced at our own plant. Translucent structures (tempered glass, insulating glass units or polycarbonate) are installed with seals that prevent air leakage. All utility entries pass through sealed penetrations. An airlock or vestibule is provided for staff entry — this keeps the envelope intact every time someone goes in.

Climate control and ventilation

The specified temperature, humidity and CO₂ concentration are maintained inside the block. Air is recirculated through a heat recovery unit and, where necessary, through a heat pump or a chiller. The number of air changes and the direction of the airflow are calculated for the crop and the operating procedure. CO₂ enrichment is used with supplementary lighting and intensive photosynthesis.

Air filtration (HEPA H13–H14)

This is the key component of a closed-loop greenhouse. HEPA H13 or H14 filters are installed on the supply line: they retain fungal spores, pollen and most pathogens. The same stage is installed on the exhaust when the facility works with quarantine objects. The pressure drop across the filters is monitored by sensors and displayed in the SCADA system.

Water treatment and plant nutrition

Nutrition is delivered by a hydroponic or aeroponic system with dosing of the solution. EC and pH are measured in real time. Water passes through reverse osmosis and UV disinfection, which rules out infection entering with irrigation. Drainage is collected in a closed loop, disinfected and returned to recirculation.

Lighting and supplementary lighting

Growth chambers and vertical farms use LED grow lights with a defined spectrum and adjustable intensity. In tall greenhouse blocks with supplementary lighting, dynamic control by growth phase is added. The spectrum and the number of lighting hours are selected for the crop.

Automation and SCADA

All parameters are brought together in a SCADA system with logging and alarms. The operator sees the microclimate of each zone, the pressure drop across the filters, nutrient solution consumption and the status of the airlocks. Every deviation is recorded — a requirement both for certification and for the procedures of work with phytosanitary facilities.

Basic microclimate parameters

The exact values are selected for the crop, the operating procedure and the biosafety requirements.

Cost and lead times

The price of a facility depends on its area, the filtration class, the set of systems and the crop. Indicative lead times:

• A simple growth chamber with HEPA filtration and basic automation — from 8 months for design and construction
• A full sealed greenhouse with climate control, hydroponics and SCADA — 10–14 months
• Facilities for pharmaceuticals and work with quarantine pathogens — to an individual schedule that allows for certification

Costing is done on a project basis. A price per square metre cannot be given in advance for facilities of this kind: the requirements for filtration, sealing and automation vary too widely. Once the input data has been collected, an engineer prepares an indicative estimate and the list of engineering systems.