LED, HPS and metal halide: a comparison table
Power with ballast, flux, depreciation and life: a 250 W HPS lamp, a 400 W metal halide lamp and an LED Prom 200W by catalogues, the EU regulation and the IES file.
Contents
Short answer: on system power and efficacy an LED luminaire beats both lamps, but not “several times over”. A 250 W HPS lamp draws about 275 W and gives 30,000 lm, a 400 W metal halide lamp about 440 W and 32,000 lm, and the LED Prom 200W 200 W and 26,000 lm by its IES file. The gain starts where a site is recalculated to the norm, not where a luminaire is fitted one for one.
All lamp figures are data sheet values from manufacturers’ catalogues and EU Regulation 245/2009. The luminaire figures come from the 2018 IES file: they are calculated values, and the LM-79 report on the assembled luminaire is in progress.
Comparison table
| Parameter | HPS 250 W | Metal halide 400 W | LED Prom 200W |
|---|---|---|---|
| Power with ballast | 275 W (up to 294 W at the minimum ballast efficiency) | 440 W | 200 W |
| Flux of a new lamp or luminaire | 30,000 lm (Lisma DNaT 250-5M) | 32,000 lm (Philips HPI-T Plus 400 W) | 26,000 lm by the IES file |
| Flux per system watt (calculated) | about 109 lm/W | about 73 lm/W | about 130 lm/W |
| Flux depreciation, EU regulation minimum | at least 85% at 16,000 h | at least 80% at 12,000 h | per the LM-80 of the module maker, not published |
| Catalogue life | 24,000 h (Lisma) | per the lamp data sheet | calculated, per LM-80 and TM-21 |
| Colour rendering | Ra about 25 | per the lamp data sheet | per the product data sheet, in preparation |
| Where the light goes | part of the flux goes up to the roof in a round reflector | depends on the housing | the intensity curve from the IES file |
Lamp flux and flux out of a luminaire are different quantities: the reflector and glass of an old housing absorb part of the light. We do not know that efficiency and do not include it, so the “flux per watt” row looks better for the lamps here than it does on site.
What a one-for-one swap gives
- 250 W HPS to Prom 200W: 275 W against 200 W, 27% less power, but flux of 30,000 against 26,000 lm, 13% less. A luminaire-for-luminaire swap does not pass on flux; it is designed to the norm.
- 400 W metal halide to Prom 200W: 440 W against 200 W, 55% less power, flux of 32,000 against 26,000 lm, 19% less at the nominal flux of a new lamp. By 12,000 hours the lamp holds at least 80% at the regulation minimum, about 25,600 lm, and after that the lamps are replaced across the whole hall.
- The design to the norm decides: a typical road on 27 HPS luminaires gives about 30 lx where ShNK asks for 4-6 lx on category V service roads. The figures are estimates and are not guaranteed before measurement on site.
Where each lamp is found
HPS is the most common lamp in warehouses, halls, streets and fuel stations. Metal halide lamps are found in halls and sports venues. HPS is not used in a hall with quality control: colour rendering Ra is about 25, and labels cannot be read under such light. An LED luminaire is chosen by its intensity curve and a calculation to the norm, not by power.
How to compare on your own site
- Take the data sheet of the old lamp and the IES file of the new luminaire: the IES viewer draws the curve and checks the flux against the one stated in the file.
- Set the norm from the summary table and the maintenance factor MF.
- Calculate the number and layout in DIALux, and the savings in the calculator. The calculator shows a warning itself if the flux of the new layout is below the old one.
The detailed HPS replacement calculation is in Replacing HPS with LED.
Frequently asked questions
Which is more economical: LED, HPS or metal halide?
On system power the LED luminaire draws less: 200 W against 275 W for a 250 W HPS lamp and 440 W for a 400 W metal halide lamp. But the luminaire flux is also below the lamp’s nominal flux, so the outcome is calculated to the illuminance norm, not by power.
How many times more economical is an LED luminaire than HPS?
Not “several times” in a one-for-one swap: by the catalogues it is 27% less power for a 250 W HPS lamp replaced with Prom 200W, at 13% lower flux. The gain is much larger where the old layout is over-lit relative to the norm.
What flux depreciation does the EU regulation allow for these lamps?
At the minimum of EU Regulation 245/2009 a metal halide lamp must hold at least 80% of its flux at 12,000 hours and an HPS lamp at least 85% at 16,000 hours. This is the regulation minimum, not data for a specific lamp.