Introduction to greenhouse structures
The majority of greenhouses worldwide are designed for commercial use, with the primary goal being economic profit. In commercial greenhouses, selecting a suitable location based on the crop, proximity to consumer markets, low operational costs, energy supply, regional advantages and security, easy access to information, and skilled labor are essential factors for success. These types of greenhouses are typically built on relatively large areas.
In greenhouses that produce seasonal crops, operations cease at the end of the growing season. However, in year-round greenhouses, the production period is much longer, requiring more equipment to maintain optimal climatic conditions across different seasons. Most of these greenhouses are covered with polyethylene materials.
Research greenhouses
The purpose of these greenhouses is research. This research may focus on production methods, studying pests and diseases, or planning high-efficiency production. The dimensions of these greenhouses are smaller, but they are equipped with more advanced and precise systems.
In research on diseases and pests in experimental greenhouses, we face limitations in ventilation and air exchange between the inside and outside of the greenhouse. Reliability and backup systems are of particular importance in research greenhouses, as system failures can ruin the results of months-long experiments. Monitoring systems and data loggers are more commonly used in these greenhouses.
Educational greenhouse
Educational greenhouses share similar characteristics with research greenhouses. Due to their educational purpose, using low-noise equipment is important. Unlike commercial greenhouses, where aisle widths are minimized, educational greenhouses feature wide and spacious aisles to accommodate large groups of students working simultaneously.
These greenhouses must support both soil-based cultivation and tabletop (bench) growing systems. Safety and the use of durable coverings are also essential requirements for educational greenhouses.
Recreational greenhouse
Greenhouses that are built in homes or nursing homes and the goal is to connect more with flowers, plants, and nature are called recreational greenhouses. If a greenhouse is built in a nursing home, it should be wheelchair accessible and have a suitable entrance slope. The climatic conditions of these greenhouses are generally chosen for the maintenance of all plants.
Shop greenhouse
Retail Greenhouses, like all retail spaces, must be designed and built to maximize customer dwell time. A high ceiling is particularly crucial in retail greenhouses.
Key requirements include:
Aesthetic appeal and proper plant arrangement
Wide aisles to accommodate shopping carts
Dedicated climate zones (for tropical and cold-weather plants)
A potting/packaging station for repotting and wrapping purchases
Customer flow design, including:
Pathways from checkout to parking
Easy plant transport to vehicles
Adequate parking and hassle-free accessibility
These elements are critical for optimizing the retail experience in greenhouse settings.
Greenhouse classification based on coverage
1. Polyethylene (PE) Covering
The majority of commercial greenhouses worldwide use polyethylene (PE) films. In fact, the modern greenhouse industry began and expanded with the advent of wide polyethylene plastics.
Key Advantages:
Lightweight and adaptable for large-span structures.
Manufactured in wide rolls, including triple-layer PE films for enhanced durability.
Special additives such as:
Anti-UV (to block ultraviolet radiation)
IR (Infrared) blockers (for better thermal control)
Anti-dust (to maintain light transmission)
Anti-fog (to prevent condensation droplets)
Optimized performance makes PE the preferred choice, driving its increasing adoption in greenhouses globally.
Structural Considerations:
PE-covered structures are classified as lightweight frameworks.
The lifespan of PE films is limited by environmental conditions (e.g., sunlight, wind, temperature fluctuations).
Double-layer inflated PE systems (with compressed air) are often used to improve thermal insulation.
2. Polycarbonate Covering
Polycarbonate coverings are primarily used for permanent structures and in regions with significant day-night temperature variations, where they demonstrate superior performance. This material is also widely employed for the sidewalls of polyethylene greenhouses.
Key Considerations:
Requires specialized profiles for proper installation
Demands precise installation to prevent:
Moisture infiltration into inner layers
Subsequent algae and fungal growth
Technical Advantages:
Excellent thermal stability for extreme temperature fluctuations
High durability for permanent structures
Commonly combined with polyethylene structures for enhanced performance
Note: Proper installation is critical to maintain the material's integrity and prevent biological contamination between layers.
3. Glass Covering Systems
Glass coverings are primarily utilized in two key scenarios:
Permanent greenhouse structures requiring long-term durability
Maximum light transmission applications where optimal photosynthesis is critical
Technical Advantages:
High-tech integration: Supports seamless installation of advanced mechanisms and climate control systems
Superior light penetration: Delivers 90-92% light transmission for enhanced plant growth
Structural classification: Considered premium technology in protected agriculture
Operational Considerations:
Requires robust framing systems to support weight
Higher initial investment but extended lifespan
Ideal for research facilities and high-value crop production
Note: Modern glass greenhouses often incorporate smart glazing technologies and automated environmental controls for precision agriculture applications.
In all greenhouse models, the goal is to absorb maximum light and then increase the temperature in the greenhouse (greenhouse effect). The direction of transpiration inside the greenhouse and the type of covering are effective in the appearance of the greenhouse. The figure below shows all the common models in the greenhouse.
