Diffuse reflective glass—also widely known as scattering glass or anti-reflective (AR) glass—is a high-performance glazing material purpose-built for modern agricultural greenhouses. Unlike traditional clear glass that creates harsh shadows and uneven light distribution, this specialized glass optimizes light diffusion and transmission, directly boosting crop yields and energy efficiency. As Dutch horticultural research firm Wageningen University & Research (WUR) confirms, over 90% of new commercial greenhouses in the Netherlands rely on diffuse glass for superior growing conditions. This guide explores its core properties, critical specifications, and expert selection tips aligned with industry best practices.
Core Optical Concepts: Haze & Transmittance
When evaluating diffuse glass, two metrics are crucial: haze and hemispherical transmittance. According to the international standard ASTM D1003, haze refers to the percentage of light rays that are deflected at an angle greater than 2.5° after passing through the glass—light rays within 2.5° are considered direct light, and the remainder are diffuse light.
Haze & Scattering: Higher haze = stronger light scattering (e.g., 70% haze delivers more uniform light than 10% haze).
Haze & Transmittance: A critical tradeoff exists—greater haze reduces hemispheric transmittance (total light passing through), while lower haze boosts transmittance but increases direct shadows.
Crop Impact: Diffuse glass extends daily light exposure for crops by 1–2 hours compared to standard glass, with WUR noting 5–10% higher yields for tomatoes and cucumbers.
Anti-reflective glass is simply coated scattering glass. The AR coating minimizes surface reflection, elevating transmittance while retaining customizable haze levels. Top-tier AR greenhouse glass achieves up to 98.5% light transmittance—the highest in commercial horticulture.
Key Specifications of Greenhouse Diffuse Glass
Professional diffuse reflective glass has four standardized parameters, validated by leading manufacturers like Migo Glass and Yuhua Glass.
1. Size
Common dimensions range from 900×1000mm to 1220×2600mm (tempered), with custom sizing available. Pro Tip: Finalize sizes with manufacturers pre-order to align with factory production standards—this cuts waste and secures factory-direct pricing.
2. Thickness
Two options dominate commercial use: 4mm and 5mm low-iron tempered glass.
4mm: Industry standard (68% market share), 1% higher transmittance than 5mm, and 20–30% cheaper. Ideal for mild climates with moderate heating costs.
5mm: Better insulation for cold regions, suitable for greenhouses prioritizing heat retention with favorable lighting.
3. Light Transmittance
Two primary grades meet global horticultural demands:
Standard Scattering Glass: 91.5% transmittance, ~$40 per square meter (budget-friendly for small-scale operations).
AR-Coated Glass: 97.5% transmittance, ~$60 per square meter (premium choice for large, high-yield farms; boosts crop capacity by 3–5% vs. 91.5% glass).
4. Haze Levels
Haze (10–75%) is the core functional attribute, tailored to climate and crop type:
Low haze (5%–30%): High transmittance, ideal for low-light regions or winter crops.
Medium haze (40–50%): Balanced performance, perfect for most vegetables (tomatoes, peppers).
High haze (70–75%): Maximum light uniformity, prevents leaf burn in hot, sunny climates.
Expert Buying Best Practices
Verify Optical Properties In-Person: Always inspect glass at the manufacturer’s facility—validate haze, transmittance, and coating quality with professional tools (per GB/T 2680-2021 standards). Never rely solely on product brochures.
Match Haze to Environment: High-haze glass suits tropical/subtropical regions; low-haze options work for temperate zones with limited sunlight.
Prioritize 4mm AR Glass for Most Cases: It balances cost, transmittance, and durability—backed by 80% of commercial greenhouse builders.
Final Summary
Diffuse reflective glass is the backbone of modern high-yield greenhouses. Its core specifications are:
Size: 900×1000mm (standard)
Thickness: 4mm (preferred) / 5mm
Transmittance: 97.5% (AR-coated) > 91.5% (standard)
Haze: 10%, 20%, 30%, 40%, 50%, 70%, 75%
Hemispheric Transmittance: Crop-specific (82–87% for 50% haze glass).
With data from WUR and leading glass manufacturers, it’s clear: investing in the right diffuse glass drives long-term profitability via higher yields, lower energy use, and reduced crop loss.
