Comparison Between Compact Double-Deep And Very Narrow Aisle Pallet Rack Systems
When talking about compact storage solutions, double-deep and VNA (very narrow aisle) easily come into our minds. Both are developed from the standard selective pallet racking system, whereas they have their own features and also share many connections. Warehouse owners tend to choose between them when storage capacity is at a premium.
Common details of warehouse racks
| Name | Storage rack | Material | Roll-formed steel |
| Rack levels | 2~15 tiers per bay | Color | Customized, Green, Orange, Blue, Yellow |
| Upright Frame Height | 2500mm~15000mm | Load Capacity | 500~3000kg per level |
| Beam Width | 1000mm~3900mm | Upright Depth | 700mm~1500mm |
| Finish | Epoxy powder coated for corrosion prevention | ||
| Usage | Pallet loads storage, warehouse storage, carton and boxes items storage | ||
| Package | Plastic stretch film, corrugated paper, cartons, wooden bars, crates, metal strips, etc. | ||
| Accessories | Bolts and nuts, upright protectors, wire decks, etc. | ||
| Certification | RMI/AS4084-2012 /CE/ ISO9001 | ||
| Delivery time | 7~25 days as per order quantity | ||
| Assembly & installation | Detailed assembly instructions are available | ||
Similarities
►Both use standard selective pallet racks as their basic storage unit;
►Both have denser storage capacity compared to selective racking;
►Both can store more products and save a lot on building footprint costs;
►Both need special forklifts for product handling: VNA forklifts and deep-reach forklifts.
Differences
►Different configurations
In a very narrow aisle racking system, the rack configuration stays the same with standard pallet racks in one row against the wall and two rows back-to-back. Also, its storage bay is relatively high for space-saving with a maximum height reaching up to 18m;
But in a double-deep racking system, three or four rows of racks stand together showing a layout of 3 or 4 pallets deep as the drawing indicated below. And the overall height of this structure is limited by the maximum reach height of double-deep forklifts.
►Different aisle width
VNA system uses narrowed aisles ranging from 1.8~2.5m for space-saving, while double-deep maintains spacious aisles by eliminating its quantity.
►Different accessibility and selectivity
Very narrow aisle pallet rack offers direct access and full selectivity with only one pallet deep, while double-deep are compromised with several pallets deep structure.
►Different stock rotation
The very narrow aisle rack follows "first pallet in, first pallet out" principle, but the double deep system obeys "last product in, first product out".
►Different storage items
VNA system best suits high-turnover products with great access and selectivity, taking full advantage of floor space, while double-deep only offers medium inventory flow and access, providing a great solution to similar products with fewer SKUs. Especially popular among freezers and cold warehouses, the double-deep racking system is widely used in the food, beverages and tobacco industry.
