Which statement about odor control in HVAC systems is accurate?

Which statement about odor control in HVAC systems is accurate?

• A. No odors can be removed by filtration.
• B. Some odors can be eliminated with activated charcoal filters.
• C. Odors are always eliminated by standard air cleaners.
• D. Odor control is unrelated to filtration.

Answer: (B)

Odor control in HVAC relies on filtering gases, not just particles. Ordinary particulate filters capture dust and pollen but don’t remove many smells because odors come from volatile compounds in the air. Activated carbon filters, or carbon-impregnated media, have a porous structure with a large surface area that adsorbs gas-phase odor molecules as air passes through. This adsorption can noticeably reduce odors, especially common ones like cooking fumes or solvent vapors, provided the carbon bed is appropriately sized and maintained (adequate contact time and timely replacement). So, the best statement is that some odors can be eliminated with activated carbon filters. Other options overstate or misstate filtration’s role: standard filters don’t reliably remove odors, odors aren’t always eliminated by standard air cleaners, and odor control is not unrelated to filtration.

Odor control in HVAC relies on filtering gases, not just particles. Ordinary particulate filters capture dust and pollen but don’t remove many smells because odors come from volatile compounds in the air. Activated carbon filters, or carbon-impregnated media, have a porous structure with a large surface area that adsorbs gas-phase odor molecules as air passes through. This adsorption can noticeably reduce odors, especially common ones like cooking fumes or solvent vapors, provided the carbon bed is appropriately sized and maintained (adequate contact time and timely replacement).

So, the best statement is that some odors can be eliminated with activated carbon filters. Other options overstate or misstate filtration’s role: standard filters don’t reliably remove odors, odors aren’t always eliminated by standard air cleaners, and odor control is not unrelated to filtration.