You simply cannot buy a better tankless water heater. Each of the tankless water heaters on our shortlist is a top choice in its price/performance bracket. However, the overall winner of our âBest of the Bestâ award is definitely the Stiebel Eltron Tempra 24 Plus.
The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. 1000 lumens, concentrated into an area of one square metre, lights up that square metre with an illuminance of 1000 lux.
The lux (symbol: lx) is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area. It is equal to one lumen per square metre. In photometry, this is used as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface.