LEDs save energy twice
The first saving is direct: an LED strip produces the same useful light on the product with less electrical power than a fluorescent tube. The second is indirect: less power in the cabinet means less heat for the compressor to remove. In a closed cabinet almost all of the lamp's power ends up as heat inside or at the edge of the cold space, so the indirect saving can be substantial.
LEDs like the cold; tubes do not
Fluorescent tubes give less light when they are cold, and inside a freezer they can be slow to start and dim. LEDs are semiconductors that generally perform better at low temperatures, with good output from the moment they switch on. That makes them particularly well suited to freezers and ice-cream display cabinets.
LEDs are also directional. They can be placed on door mullions or shelf fronts to put light on the product instead of lighting the inside of the cabinet roof.
LED versus fluorescent in display cabinets
| Aspect | LED | Fluorescent tube |
|---|---|---|
| Power for similar product lighting | Lower | Higher |
| Heat added to cabinet | Less | More, including ballast heat |
| Performance in cold | Good, instant full output | Reduced output, slower start |
| Light direction | Directional, can target shelves | All-round, more wasted light |
| Breakage risk | No glass tube | Glass tube can shatter in food areas |
| Dimming and controls | Easy to dim or switch with sensors | Limited |
Light quality still matters
Saving energy is pointless if products look dull. Colour temperature and colour rendering affect how fresh produce, meat, cakes and drinks appear. Cool white suits drinks and dairy; warmer tones often suit bakery and pastry displays. Ask for a colour rendering figure and, if possible, see the cabinet lit with your products in it before you buy.
Controls add more savings
- Switch cabinet lighting off or dim it when the shop is closed, ideally from the controller or a timer.
- Motion sensors on low-traffic cabinets can dim lights until a shopper approaches.
- Separate switches for canopy and shelf lighting allow partial lighting in quiet hours.
- Make sure light controls are linked to night blinds or eco modes where the cabinet has them.
Estimating the saving before you switch
You can estimate the direct saving with simple arithmetic. Add up the wattage of the existing tubes and ballasts, subtract the wattage of the proposed LED fittings, and multiply by the hours the lights are on each day. That gives the daily kWh saved by the lamps themselves.
Then remember the indirect saving. Heat from lamps inside the cabinet has to be removed by the refrigeration system, which uses electricity to do it. The exact figure depends on the cabinet's efficiency, so treat the indirect part as a bonus on top of the direct saving rather than a precise number. If you want certainty, meter one cabinet for a week before and after the change.
- Example: two 36 W tubes plus ballast losses replaced by LED strips of about 30 W in total, lit 16 hours a day, saves roughly 0.7 to 0.8 kWh a day directly (illustrative figures).
Retrofitting older cabinets
LED retrofit kits are available for many older cabinets. A proper retrofit replaces the tube, holder and ballast, and uses fittings rated for cold, damp conditions. Avoid cheap 'plug-in' tubes that are not designed for refrigerated use; condensation and cold can shorten their life. Have the work done by someone who understands both the electrical safety and the food-zone requirements.
Frequently asked questions
- Will LED lights make my cooler colder?
- They reduce the heat added inside the cabinet, so the compressor runs less to hold the same temperature. The set point stays the same; you simply use less energy to reach it.
- Do LEDs work in deep freezers and ice-cream cabinets?
- Yes. LEDs generally perform well at freezer temperatures and switch on at full brightness, which is one reason they have become standard in frozen display.
