What you are buying, and what it costs you
An air-curtain multideck has no doors between the customer and the product. That is the whole point: no door to open means no hesitation, and in most categories an open display outperforms a closed one on sales per metre of aisle.
The cost is energy and, in a humid climate, condensation. With no physical barrier, the cabinet exchanges heat and moisture with the shop continuously. Depending on climate class and aisle conditions, an open multideck can consume meaningfully more energy than an equivalent glass-door cabinet doing the same job — the figure most often quoted is in the range of thirty to fifty per cent, and in a hot, humid store it can be worse.
So the question is not whether an open multideck is efficient. It is whether the sales uplift in your category is worth the running cost, and whether the cabinet you buy is at the good end or the bad end of that range.
Number 1: the load line and effective display area
Every multideck is designed around a load line that the air curtain has to pass over. Product stacked above that line deflects the curtain outwards into the aisle, which both warms the product and loads the refrigeration system.
This makes the quoted shelf area a marketing figure and the usable display area a real one. If a cabinet claims a shelf depth that only works when it is half empty, the extra depth is decorative. Before comparing two cabinets, compare the shelf depth available below the load line at every level.
Measured on the display, not on the drawing
- Clear depth of every shelf below the marked load line
- Vertical pitch between shelves at the setting you would actually use
- Total usable area in square metres — not total shelf area
- The height of the tallest standard pack you sell, checked against the top shelf
Number 2: the temperature the product actually sees
Open cabinets quote a discharge air temperature, which is the coldest air in the cabinet. What matters commercially is the warmest product surface position, which is usually the front of the top shelf where the curtain has picked up the most heat.
The gap between those two figures is the honest measure of a multideck design. Ask for the measured product simulator temperatures at three positions: back of the bottom shelf, middle, and front of the top shelf. A cabinet that holds all three within its stated band at the design ambient is doing real work. A cabinet that quotes only the discharge temperature has told you nothing you can use.
Two open multidecks can carry the same discharge temperature and differ by four degrees at the front of the top shelf. Only one of them is selling safe food.
Number 3: ambient class and the real energy figure
An open multideck tested at class 3 and installed in a hot, humid aisle is the single most common specification mismatch in retail refrigeration. Because there is no door, the cabinet is directly exposed to whatever the store does — and stores are hot near entrances, near bakery ovens, and wherever the air conditioning does not reach.
- Ask for the energy consumption figure at your climate class, not the lowest one available
- Ask what the figure becomes at the aisle ambient you actually measure, in the worst month
- Check the aisle for air-conditioning diffusers aimed at the cabinet face
- Confirm the store has humidity control if the cabinet will run in a coastal or tropical market
Number 4: night covers and their payback
This is the cheapest improvement available on an open cabinet, and it is left out of most quotations because it is sold as an accessory. A night blind pulled down at close reduces the cabinet load for the hours when the store is empty and the doors are shut.
The economics are straightforward: the blind adds a small fraction to the cabinet price and recovers several per cent of daily consumption, assuming staff actually pull it down. That assumption is the entire risk. If the closing routine does not include the blind, the accessory is a cost with no benefit, so it is worth agreeing the routine at the same time as the order.
| Parameter | Open air-curtain multideck | Glass-door cabinet |
|---|---|---|
| Sales effect in impulse categories | Higher | Lower |
| Energy consumption | Higher — no physical barrier | Lower |
| Condensation risk on the front | On product and shelves | On the glass only |
| Loading discipline required | High — load line is critical | Low |
| Night blind or cover | Strongly recommended | Not applicable |
| Best suited to | High-traffic impulse categories | Staples, chilled convenience |
How to make the decision
Compare the cabinets on usable display area, product temperature at the worst position, energy at your aisle ambient, and the cost of the night-blind routine. If the open cabinet wins on all four, buy it. If it wins on sales but loses badly on energy, a hybrid aisle — open for the impulse categories, glass doors for the staples — is usually the better answer than either extreme.
Chen has specified cabinets for markets in the Gulf, West Africa and South-East Asia since 2014, and handles hot-climate RFQs at Dixue.
