Ducted vs Ductless Fume Hoods: A Complete Comparison
Choosing between a ducted and ductless fume hood is one of the most important decisions in lab design. The right choice depends on what chemicals you use, your building infrastructure, and your budget. This guide covers the key differences.
How Ducted Fume Hoods Work
Ducted fume hoods connect to the building’s HVAC exhaust system. Room air enters the hood face, passes over the work area capturing fumes, and is exhausted through ductwork to the building exterior. The air is never recirculated.
Best for:
- Labs using a wide variety of chemicals including acids, bases, solvents, and carcinogens
- High-volume chemical work and extended-duration reactions
- Labs handling perchloric acid, hydrofluoric acid, or radioisotopes (which require specialty hoods)
- Facilities with existing HVAC infrastructure and ductwork
How Ductless Fume Hoods Work
Ductless (recirculating) fume hoods pull air through activated carbon or HEPA filters, remove contaminants, and return cleaned air to the room. No ductwork or building modifications required.
Best for:
- Labs with limited or no ductwork infrastructure
- Teaching labs, prep labs, and light-use chemistry applications
- Temporary or portable lab setups
- Facilities where adding ductwork is prohibitively expensive
Comparison Table
| Feature | Ducted | Ductless |
|---|---|---|
| Chemical compatibility | Nearly all chemicals | Limited to filter type |
| Installation cost | $15,000–$40,000+ (with ductwork) | $3,000–$12,000 (no ductwork) |
| Operating cost | $3,000–$8,000/year (energy) | $500–$2,000/year (filters) |
| Portability | Fixed installation | Can be relocated |
| HVAC impact | Exhausts conditioned air | No impact on HVAC |
| Filter replacement | None | Every 3–12 months |
| Safety level | Highest — no recirculation | Good — depends on filter match |
| Regulatory acceptance | Universal | Check with your EH&S officer |
Key Decision Questions
- What chemicals will you use? If you work with carcinogens, perchloric acid, HF, or a wide chemical mix — go ducted.
- Does your building have ductwork? If not, ductless saves $10,000–$30,000 in construction.
- How often will you use the hood? Heavy daily use favors ducted. Occasional use favors ductless.
- Is this a permanent installation? If you may relocate, ductless is portable.
Need Help Choosing?
Our lab design team will review your chemical inventory and recommend the right hood type and size. Contact Labs USA for a free consultation.