Open Multideck or Glass Doors? Do the Maths Before You Buy

Ask whether an open multideck or a glass-door display fridge is “better” and you will get the wrong argument very quickly.

One side talks about energy. The other talks about sales. Both can be right, and both can miss the point.

The real decision is whether the extra accessibility of an open cabinet produces enough operational or sales value to justify its higher energy demand in that particular position.

Why open cabinets use more energy

Every refrigerated display is trying to maintain a cold internal environment while standing in a warmer shop. A glass door creates a physical barrier. An open multideck relies on a moving curtain of refrigerated air, which is far more exposed to warm air, draughts and disturbance.

TEFCOLD previously published a comparison between one of its open multidecks and a glass-door model. Its example showed a very large difference in annual electricity consumption. The calculation used historical European energy pricing, so it should not be copied as a current UK payback claim, but the underlying lesson remains valid: frontage can have a major effect on running cost.

Use your electricity tariff, not somebody else’s headline

The basic annual-cost calculation is simple:

Annual electricity use in kWh × your effective price per kWh = estimated annual energy cost

For example, a difference of 3,000kWh a year costs £750 at £0.25/kWh or £1,050 at £0.35/kWh. The same cabinet comparison can therefore produce a very different payback depending on the contract and site.

This is an estimate, not a promise. Ambient temperature, loading, maintenance, door opening, ventilation and positioning all affect real consumption.

Then measure the retail job

Energy is only half of the calculation. Record what the fixture is expected to do.

• How many units does it sell each day?
• Is it serving a breakfast or lunchtime rush?
• Do customers approach with a basket, a phone or a coffee already in hand?
• Would doors obstruct the aisle?
• Is the display next to an entrance or another source of moving warm air?
• Is stock left in the cabinet overnight?

A door-equipped model can still merchandise brilliantly. An open cabinet can still be the correct commercial decision. What matters is that the reason can be demonstrated.

Craven’s verdict

For many stores, doors provide a compelling route to lower energy use. For some rapid food-to-go positions, the accessibility of an open front remains commercially valuable.

Do not let either side win with a slogan. Compare annual kWh, usable display space, the customer journey and the actual product margin. Then make the decision cabinet by cabinet.

The stunt — The £1,000 Shelf: Choose one metre of existing chilled display and calculate its annual electricity cost, gross product margin and waste. Put the three numbers on a card above the cabinet for the management team. Suddenly, “just a fridge” becomes a measurable part of the business.

Source: TEFCOLD open-front versus closed-door comparison