CH-93-18-2 -- Analysis of Furnace-Mount Humidifier for Microbiological and Particle Emissions, Part II: Particle Sampling and Results PDF

A ductwork loop was constructed that simulated a home, forced-air heating system to test the transmission of naturally occurring particle matter. Three common types of furnace-mount humidifiers were operated over 90-day periods under controlled conditions. Air samples were collected and evaluated using an impactor, a gravimetric sampler, and a light-scattering device. Collected samples from the airstream and scale from the humidifiers were analysed using EDS XRF. Scale samples were also analysed using X-ray diffraction. The impactor and gravimetric samples were taken from the fresh air inlet duct and the furnace outlet duct. A light-scattering device continuously monitored the airstream in the duct to determine whether there were increases in particle matter when the humidifier was operating. There was no evidence from any of the sampling that particle matter was transmitted from the humidifiers to the ductwork.

KEYWORDS: humidifiers, boilers, air pollution, indoor, bacteria, particles, sampling, ducts, warm air heating, testing, calculating, x radiation, diffraction, monitoring, operations.