<h2>The 8 Numbers That Matter</h2>
<h3>1. Delivered Lumens (Not LED Lumens)</h3>
<p>LED lumens = raw output from the chip. <strong>Delivered lumens</strong> (also called fixture lumens or system lumens) account for lens losses, thermal degradation, and driver efficiency. Always compare delivered lumens. A fixture claiming "20,000 LED lumens" might deliver only 17,000.</p>
<h3>2. System Efficacy (lm/W)</h3>
<p>Delivered lumens ÷ input watts = efficacy. Above 130 lm/W is good. Above 160 lm/W is DLC Premium territory. Anything under 100 lm/W is below current standards — don't buy it.</p>
<h3>3. Input Wattage (Not LED Wattage)</h3>
<p>The wattage your electric meter sees. Always calculate energy savings on input watts, not LED watts. They can differ by 5-15%.</p>
<h3>4. CCT (Correlated Color Temperature)</h3>
<p>2700-3000K = warm white (restaurants, retail). 4000K = neutral white (offices, schools). 5000K = cool white (warehouses, parking lots). Don't overthink it — 4000K or 5000K covers 90% of commercial applications.</p>
<h3>5. CRI (Color Rendering Index)</h3>
<p>CRI 70 is minimum for commercial. CRI 80 is standard and required for DLC Premium. CRI 90+ for retail/art display only — it costs more and rarely justified for industrial or outdoor applications.</p>
<h3>6. L70 Lifespan</h3>
<p>The hours until lumen output drops to 70% of initial. 50,000 hours is baseline. 100,000 hours is premium. At 12 hours/day operation, 100,000 hours = 22 years. Don't pay premium for 150,000 hour ratings — the driver will fail long before the LEDs do.</p>
<h3>7. IP Rating</h3>
<p>First digit: dust protection (6 = fully sealed). Second digit: water protection (5 = spray, 6 = powerful jets, 7 = immersion). IP65 is minimum for outdoor. IP66 for carwash, heavy rain, or hose-down environments.</p>
<h3>8. Surge Protection Rating</h3>
<p>Measured in kV. Minimum 6kV for general commercial. 10kV for outdoor. 20kV for areas with frequent lightning strikes. Undersized surge protection is the #1 cause of premature LED driver failure.</p>
<h2>Specs You Can Usually Ignore</h2>
<ul>
<li><strong>Power factor (>0.90)</strong>: All commercial-grade fixtures exceed this. Only matters for very large installations.</li>
<li><strong>THD (<20%)</strong>: Same — standard in any quality fixture.</li>
<li><strong>Operating temperature range</strong>: -40°C to 45°C covers everywhere in North America.</li>
</ul>
<p>Every ForgeLightCo product page includes a downloadable cut sheet with all 8 of these numbers clearly listed. If a competitor can't provide them, that's your answer.</p>