Reading LED energy labels: watts, lumens and kWh per 1,000 hours

An LED energy label helps you compare energy performance, while lumens, watts and operating hours answer different questions. Keep those numbers separate when replacing a bulb: choose the light and fitting you need, then compare its energy information.

For a concrete model example, see the existing Integral Sunset ST64 E27 amber dimmable bulb. Integral’s current information for model ILST64E27D008 lists energy class D on the A–G scale. The example below uses that exact model; it does not assign a rating to other lamps.

Standard colour arrow generated with the GOV.UK energy-label template using Integral’s published D classification. See the manufacturer’s model information and confirm the actual supplied lamp and label.

Read the label and the specification together

The rescaled light-source label uses an A–G efficiency scale. Older A+, A++ and similar labels belong to a different scale. Compare current model information rather than ranking two lamps by letters taken from different label generations.

The model identifier matters: use the label and product information for the exact lamp and version. A similar-looking bulb, another cap version or an old packaging photograph may not represent the same specification.

Four fields to keep separate

Cap type, dimensions, permitted fitting conditions and dimmer compatibility remain separate checks. An efficiency class does not identify a B22 or E27 cap, establish that a bulb fits an enclosed fitting or confirm compatibility with an existing dimmer.

What “kWh per 1,000 hours” means

The light-source label states electricity consumption over 1,000 hours in on-mode. It is an energy quantity for a stated operating period, rather than a yearly household bill. The declared label figure is rounded up to a whole kWh, so keep the manufacturer’s stated power and label information available when comparing models.

Use your actual lamp power and operating hours for an estimate. Dimming, controls, standby functions and the operating conditions of the product can affect real use. A cost estimate also needs your current electricity unit rate; this guide makes no tariff, annual-saving or payback promise.

A manufacturer example: one model, several separate numbers

Integral’s current ILST64E27D008 reference lists:

• Energy class D on the rescaled A–G scale.
• 5.9W power and 806 lumens light output.
• 2200K very warm light, amber glass and an E27 screw cap.
• Dimming with a compatible control arrangement.

Those fields describe different aspects of the same model. The required cap, light output and colour still need to match your application. Confirm that the fitting has room for the ST64 shape and that any dimmer is compatible with the actual lamp. The 10W arithmetic example above is deliberately separate from this product’s specification.

A short check before buying a replacement

• Match the cap and confirm the space and fitting requirements.
• Choose the required lumens and colour temperature.
• Check whether dimming is needed and confirm compatibility.
• Compare the current model’s energy class, power and product information.
• Confirm the actual supplied reference and pack where matching an earlier lamp or a particular specification matters.

You can view the exact Integral Sunset ST64 E27 listing or ask APM to check a lamp reference before ordering. Send a safely obtainable photograph of the bulb or packaging details; do not remove electrical covers or disturb a fitting to obtain a photo.

Call 020 8702 8080 / WhatsApp the shop, or call 07737 263641 / WhatsApp the company mobile. See our Acton counter and contact details. Confirm availability and collection arrangements before travelling.

Sources

GOV.UK product energy-labelling guidance; GOV.UK light-source label fields and templates; Integral ILST64E27D008 product information. Checked 3 November 2026. This article explains reading and comparison; use the current supplier label and product information for the exact model.