The respective advantages of multi-span greenhouses compared to film multi-span greenhouses

1. **Light Transmittance**:
- Glass multi-span greenhouses: Utilizing high-quality glass materials, they offer a high and stable light transmittance, providing excellent lighting conditions conducive to plant growth.
- Film multi-span greenhouses: Although modern agricultural films have good light transmission properties, their light transmittance is slightly lower compared to glass. Moreover, over time, the light transmittance may decline due to aging and other factors.

2. **Insulation Effect**:
- Glass multi-span greenhouses: The glass material itself has a relatively high thermal conductivity coefficient, so its insulation performance is relatively poor in cold seasons; however, by installing double or even triple-layer insulating glass, the insulation effect can be effectively improved.
- Film multi-span greenhouses: The film material is relatively thin and light, and its insulation performance is not as good as that of glass. However, in summer, the indoor temperature can be regulated by adding shading nets, etc., and in winter, additional insulation measures such as adding insulation covers need to be strengthened.

3. **Cost and Maintenance**:
- Glass multi-span greenhouses: The initial construction cost is relatively high, including the design and construction of the frame structure and the purchase of high-quality glass materials; however, in the long term, glass is durable and less prone to damage, resulting in relatively low maintenance costs.
- Film multi-span greenhouses: The initial investment is lower, making it suitable for situations with limited budgets. However, the film is prone to aging due to ultraviolet radiation and needs to be replaced every few years, increasing the operational costs in the later stage.

4. **Flexibility**:
- Glass multi-span greenhouses: Once constructed, it is relatively difficult to adjust the spatial layout or expand the scale.
- Film multi-span greenhouses: The structure is relatively simple and flexible, making it easy to renovate and upgrade according to actual needs or quickly build new units.

In conclusion, the choice of which type of multi-span greenhouse to select depends on specific usage purposes, geographical location, climatic conditions, and budgetary factors. If long-term stable and efficient production is pursued and sufficient funds are available, a glass multi-span greenhouse can be chosen; for those who wish to start a project quickly at a lower cost and are willing to undertake certain subsequent maintenance work, a film multi-span greenhouse solution may be more suitable.