Quick Wins (do these this week)
- Raise outdoor air intake to meet or exceed design (target CO₂ ≤ 800–1000 ppm during occupancy).
- Upgrade filters to MERV 11–13 (or highest your fans can handle without excessive pressure drop).
- Run systems early/late: start HVAC 1–2 hours before occupancy and purge 1–2 hours after.
- Keep RH 40–60% to reduce irritants and help comfort.
- Ban strong scents & aerosols; switch to low-VOC cleaning supplies.
- Add local HEPA air purifiers in crowded/poorly ventilated rooms (meeting rooms, call centers).
2) Ventilation & Fresh Air
- Verify minimum outdoor air (OA): open OA dampers to the designed position; avoid “economy” set-backs that starve air.
- Use demand-controlled ventilation (DCV) only if it’s tuned correctly—set CO₂ setpoints 800–900 ppm, not 1200+.
- Cross-ventilate naturally where safe: operable windows + security/insect screens; avoid drafts on occupants.
- Door undercuts/transfer grilles ensure air gets into enclosed rooms (boardrooms, clinics, server rooms).
- Purge cycles: schedule pre- and post-occupancy flushes (see schedules below).
3) Filtration (central & portable)
- Central AHU/FCU filters:
- Aim for MERV 11–13. Check fan capacity and coil/fan cleanliness to handle added resistance.
- Seal filter frames to prevent bypass.
- Portable HEPA units:
- Choose CADR to deliver ≥5 equivalent air changes per hour (eACH) for the room.
- Position away from obstructions; keep intakes/outlets clear.
4) Humidity, Temperature & Comfort
- Target RH 40–60%; use humidification/dehumidification as needed.
- Maintain 22–25 °C in cooling seasons (or your local comfort band).
- Insulate cold surfaces to prevent condensation and mold.
5) Source Control (remove pollutants at the source)
- Print/copy rooms: isolate with exhaust.
- Storerooms: seal and vent paints, solvents, and cleaning chemicals.
- Pest control: prefer traps/gel baits; avoid broad-spray pesticides during working hours.
- Fit entry mats (3-stage: scrape/absorb) to reduce dust tracked indoors.
- No smoking/vaping anywhere inside; place exterior zones downwind.
6) Cleaning & Materials
- Low-VOC paints, sealants, adhesives for renovations.
- Microfiber + HEPA vacuums; wet mop dusty areas.
- Schedule “off-gassing”: leave fresh furniture/carpets to off-gas in a ventilated area before use.
7) Monitoring & Targets
- CO₂: keep ≤1000 ppm (ideal ≤800 ppm).
- PM₂.₅: aim ≤15 µg/m³ average; investigate spikes.
- TVOCs (optional): use as a trend indicator (improve cleaning/ventilation if high).
- Dashboards: install low-cost IAQ sensors in busy zones and share weekly snapshots with staff.
8) Preventive Maintenance Schedules
Daily / Weekly
- Check OA dampers open per setpoint.
- Confirm fans running during occupied hours + purge periods.
- Inspect high-use spaces (meeting rooms) for stuffy air or odors.
Monthly
- Inspect and vacuum pre-filters.
- Check filter pressure drop; note trends.
- Clean return/transfer grilles; clear blockages.
- Verify condensate drains (clear and disinfect if slimy).
Quarterly (or per manufacturer)
- Replace main filters (MERV 11–13) or sooner if pressure drop exceeds design.
- Clean coils (evap/condenser) and blower wheels.
- Calibrate OA and CO₂ sensors; validate DCV setpoints.
- Inspect ductwork for leaks/dirt; spot clean as needed.
Biannually / Annually
- Test airflow & air changes in key rooms; rebalance if layouts changed.
- Audit fresh-air fractions and energy recovery ventilators (ERV/HRV).
- Mold inspection in plenums, insulation, and around windows.
- Review IAQ logs; adjust targets before seasonal changes.
9) Meeting Rooms & High-Density Areas (special attention)
- Boost ventilation rates during bookings (BMS event triggers).
- Add room-based HEPA units sized for ≥5 eACH.
- Auto-reset between meetings: 10–15-minute purge.
- Display CO₂ readouts; if >1000 ppm, shorten meeting/ increase purge.
10) Policy & People
- Occupancy management: avoid overcrowding; stagger schedules for dense spaces.
- Hot-desk hygiene: wipes and hand gel available; discourage desk plants that mold.
- Education: short staff brief on vents (don’t block them), scents, and window use.
Sample BMS/Manual Schedules (copy-paste)
- Weekdays:
- 05:30–07:30 Pre-purge (OA max or purge mode)
- 07:30–18:00 Occupied (normal setpoints; DCV 800–900 ppm)
- 18:00–20:00 Post-purge
- Saturdays: Half-day occupied + purge.
- Public holidays: Purge 1–2 hours morning + afternoon if security/staff present.
Troubleshooting Quick Guide
- Stuffy/odors? Check OA damper, CO₂ >1000 ppm, filter clog, fan schedules.
- Condensation/mold? Check RH >60%, insulation gaps, blocked drains.
- Dust build-up? Upgrade to MERV 11–13, seal return leaks, increase cleaning HEPA vacuums.
- Headaches/irritation? Review cleaning chemicals (swap to low-VOC), increase purges, add HEPA units.
Procurement Cheat Sheet
- Filters: Ask for MERV 11–13, low initial pressure drop, good dust holding, correct sizes, gasketed frames.
- Purifiers: True HEPA (H13/14), CADR sized to room volume (≥5 eACH), quiet mode <50 dB, replaceable filters with indicators.
- Sensors: CO₂ NDIR type; PM₂.₅ laser sensor; cloud dashboard or local export; calibratable.
Bottom Line
Great office air is filters + fresh air + discipline. Upgrade to better filtration, ventilate generously (with smart purges), and lock in simple, recurring schedules—then watch comfort and productivity rise while complaints fall.
