Indoor Air Quality Flashcards

Which active radon mitigation system is most commonly installed in homes with basements or slabs-on-grade to reduce indoor radon levels?

Answer: Sub-slab depressurization (SSD) system

Sub-slab depressurization draws radon from below the foundation slab and exhausts it outdoors before it can enter the living space, and is the most effective active mitigation method.

What is the recommended primary strategy for reducing VOC concentrations in a newly constructed or recently renovated home?

Answer: Aggressive ventilation with outdoor air to flush out off-gassed chemicals

Source ventilation (sometimes called a 'bake-out') involves opening windows and running ventilation at maximum capacity to rapidly dilute and expel VOCs released by new materials.

Lead-based paint in older homes poses the greatest health hazard when it is in which condition?

Answer: Deteriorating, peeling, chipping, or disturbed during renovation

Lead paint becomes hazardous when it deteriorates or is disturbed through sanding, scraping, or demolition, generating lead dust and paint chips that can be ingested or inhaled.

Asbestos-containing materials (ACMs) in older homes present the greatest health risk when they are in what state?

Answer: Friable, crumbling, or mechanically disturbed, releasing fibers into the air

Asbestos fibers become airborne and inhalable when ACMs are friable (easily crumbled) or disturbed by cutting, drilling, or demolition, dramatically increasing health risks.

What is the primary purpose of the combustion safety test sequence performed during a BPI whole-house assessment?

Answer: To identify conditions that could cause backdrafting or spillage of combustion gases into the living space

The combustion safety test sequence evaluates draft, spillage, and CO levels under worst-case depressurization to ensure appliances vent properly and do not endanger occupants.

Which term describes the reversal of normal flue gas flow in a vented combustion appliance, causing combustion byproducts to enter the living space?

Answer: Backdrafting, where negative house pressure reverses flue gas direction

Backdrafting occurs when negative indoor pressure or insufficient draft causes flue gases to flow in reverse, spilling dangerous combustion byproducts including CO into the home.

According to BPI standards, what is the maximum acceptable carbon monoxide (CO) concentration in undiluted flue gases from a combustion appliance before it must be shut down?

Answer: 400 ppm

BPI requires that combustion appliances producing more than 400 ppm CO in undiluted flue gas be taken out of service until the condition is corrected.