What are ASHRAE 90.1-2022 LPD targets by space type?

Open office: 0.79 W/sq ft. Retail: 1.26 W/sq ft. Warehouse: 0.33 W/sq ft. Hospital patient room: 0.62 W/sq ft. Corridor: 0.41 W/sq ft. Classroom: 0.71 W/sq ft. These are ~30% lower than 2013 standards.

How do I calculate lighting power density?

LPD (W/sq ft) = Total fixture wattage / Floor area. Include LED driver input power, not just lamp wattage. Multiply by local kWh rate and annual hours to get annual lighting energy cost.

Can I reduce LPD below code with LED?

Modern LED luminaires achieve 100-160 lumens/watt vs code-assumed 80-90 lm/W. Highly efficient offices can achieve 0.4-0.5 W/sq ft with daylight sensors and occupancy controls while meeting IESNA illuminance recommendations.

Commercial Lighting Watts Per Sqft Target Calculator

Calculate lighting power density (LPD) in watts per square foot for commercial spaces. Compare to ASHRAE 90.1 and IECC targets by space type.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the patient or scenario you are assessing. Calculate lighting power density (LPD) in watts per square foot for commercial spaces. Compare to ASHRAE 90.1 and IECC targets by space type. Use the lighting w/sqft result to inform your clinical assessment.

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Frequently Asked Questions

What are ASHRAE 90.1-2022 LPD targets by space type?

How do I calculate lighting power density?

Can I reduce LPD below code with LED?