Environmental Systems, Lighting, and Acoustics
What this domain tests
This domain tests coordination of HVAC, electrical, plumbing, lighting, and acoustics within the interior. You need to size, locate, and check systems without designing them from scratch.
Core rules and concepts
- HVAC capacity is often expressed in tons (12,000 Btu/h) and airflow in cfm. Ducts need clearance for insulation, fire dampers, and access; diffusers should not blow directly on seated occupants.
- Lighting metrics include footcandles (illuminance), lumens (output), color temperature in kelvin, color rendering index, and lighting power density in W/sf. Glare and uniformity matter as much as raw output.
- Acoustics uses STC for partition sound transmission, NRC for absorption, and reverberation time for room character. Background noise from HVAC can mask speech or annoy occupants.
- Plumbing requires slope, venting, and access; electrical requires panel capacity, receptacle circuits, and dedicated equipment loads.
Worked example
A 2,000 sf office at 0.75 W/sf has a lighting budget of 1,500 W. At 30 W per fixture, that is 50 fixtures before controls and ballast allowances. Ventilation at 5 cfm per person plus 0.06 cfm/sf for 14 people gives 70 + 120 = 190 cfm. Check that supply diffusers and returns do not conflict with the ceiling grid or sprinkler layout.
Traps
Confusing STC with NRC; sizing lighting by fixture count instead of power density; placing diffusers without checking throw; and ignoring access to valves and dampers.