Shelly Miller, PhD – University of Colorado – The Weatherization, Ventilation & Respiration Puzzle

Air Date: 1-18-2019|Episode 530

This week Shelly Miller, PhD joins us to discuss some recent research and thoughts on weatherization, ventilation & respiration. We hear a lot that we need to tighten homes and ventilate them. What does that do with respect to occupant health? Today we will go over some results from work Dr. Miller has done.

Dr. Miller is an Associate Professor at the University of Colorado Boulder in the Mechanical Engineering Department and faculty in the interdisciplinary undergraduate Environmental Engineering Program. At the University of Colorado Boulder Dr. Miller investigates indoor air quality, assesses exposures to air pollutants, and develops and evaluates air pollution control measures. Her research has included studying weatherization of homes and indoor air quality, understanding the role of ventilation systems in the transmission of infectious agents in buildings, engineering controls for reducing exposures to infectious diseases, studying ultraviolet germicidal coil cleaning technology, source apportionment of particulate matter and associated health effects, characterization of indoor air quality and the microbial communities in homes, and investigating urban air quality issues including industrial odor episodes.  Dr. Miller has received funding for her research program from the US EPA, CDC, NIOSH, NSF, NIH, ASHRAE, HUD, Alfred P. Sloan Foundation, and various private foundations and industry sponsors.

Z-Man’s Blog:

Weatherization, Ventilation & Respiration Puzzle

Shelly Miller, PhD is a Professor at the University of Colorado, Boulder
where she investigates indoor air quality, assesses exposures to air pollutants, and
develops and evaluates air quality control measures.
Nuggets mined from today’s episode:
Her current research focus is the role of ventilation on respiration and health.
We learned from reaction to energy crisis in the 1970s that the combination of tightening
buildings and building emissions had an adverse impact on human health. We are
tightening buildings again due to climate change, how will tightening impact human
Colorado Home Energy Efficiency and Respiratory Health study AKA CHEER
study. Had the opportunity to study 216 homes whose residents were at risk, low
income households. Many of the homes were older with ventilation systems installed in
a crawl space or attic. Many of the homes had existing radon mitigation systems.
Homes weatherized to different levels on a 5 Point Scale using weather-stripping,
caulking, foam sealing and duct sealing. More energy efficient appliances were also
installed.  Two teams visited the homes: the engineering team using blower door testing estimated the annual average air exchange, using a written survey and spirometry test (for suitable candidates) and a written survey the medical team measured lung function. In test
homes building age and volume related to the ventilation rates. Window weather
stripping and duct sealing were the two most effective tightening tactics.
Asthma is exacerbated by poor indoor air. Low ventilation rates increase infectious
disease (flu), irritate the central nervous system, cause headaches and other sick
building symptoms, disrupt endocrine function, lead to cancer, result in excessive
exposure to solvents.
Higher ventilation rates are linked to better health and savings in health costs.
However, traffic related air pollution + leaky homes affects health.
IAQ indicator, occupants of homes with higher ventilation rates had increased coughing;
a very surprising finding. Homes near high traffic roads had more coughing likely
caused by outdoor pollutants drawn indoors.
Challenge: What can we do creatively to bring more fresh filtered air inside and remove
all combustion related air outside, with cost effective, easy retrofit in mind?
CO levels are 4-7 times higher indoors than outdoors. Cooking in passive homes isn’t
being accounted for as it should. Find a better way.

Low CO levels in homes is an area of interest. Studying with sensitive CO sensors built
in house.
The outliers to the CHEER home study were 12 newer green standard homes built by
the City of Boulder and/or Habitat for Humanity.
A two year summer sub study was done on wildfires, traffic and indoors. Found wildfires
increased PM 2.5 and black carbon indoors while levels of Nitrogen Dioxide and Carbon
Monoxide remained consistent. During wildfires we need to quickly deploy technology
such as Air Filtration Devices to homes. A forced air heating system, recirculating with
coarse filters will remove some particulate. Preferred system is balanced ventilation with
filtered air.
Spirometry measurements, lung function association with air changes. Spirometry is a
physically challenging test which some occupants couldn’t perform. While the modeling
is unstable, it appears there is an association between more ventilation=better lung
Forests create VOCs. Ozone turns VOCs into particles.
Ozone from outdoors is highly reactive and is removed by materials indoors.
The closer we live to roads the higher the indoor concentrations of traffic related
contaminates will be excepting ozone.
Colorado Home Energy Efficiency and Respiratory Health study AKA CHEER study
found: Increased Ventilation = Increased Symptoms.
We need more clean air.
Wood burning is a big contributor to air pollution globally.
Where do we go from here? The CHEER study is a cross section of data from one
inspection. Shelly is interested in revisiting the homes for follow-up and see the affects
of new ventilation standards.
Z-Man signing off


Trivia Question:
What is the common thread running among management consultant: W. Edwards
Deming, band leader Glenn Miller, astronaut Scott Carpenter and actor Robert
All are alumni of UC Boulder
Answered by: Tom Barnes, Greenville, NC