ASHRAE Journal - September 2013 - 68

technical feature

table 1 Building processes linking IEQ, health, and building energy use.15
Process

outdoor air
ventilation

Heating

MecHanical
cooling

Particle
filtration

HuMidification

air
recirculation

building
Pressure
control

Hvac
Maintenance

Hvac cleaning

68

link to energy

link to ieQ and HealtH

• Energy used to transport and thermally condition air

• Serves to dilute indoor-generated pollutants, but also brings outdoor pollutants and
moisture into the building
• Higher rates associated with improved symptoms, respiratory health, perceived air quality,
and work performance
• In some climates (and for some systems and approaches): inadequate ventilation leads to
increased humidity, condensation, mold, and possibly allergens and vermin in houses
• Window opening may bring in noise and pollutants, create drafts, and create a security
issue

• Energy used to heat and transport air

• Affects thermal comfort
• Risk of combustion product entry to indoor air for some systems and installations
• Affects emission rates of pollutants, especially VOCs, formaldehyde, and lighter SVOCs
• Affects occupant response to pollutant exposures

• Energy used to cool, dehumidify and transport air

• Affects thermal comfort
• Risk of microbiological contamination of wetted surfaces
• Risk of condensation on occupied space surfaces when warm, humid air enters cooled
interior
• Associated dehumidification may help reduce moisture problems and microbiological
contamination
• Associated with increased health symptoms
• Can be a source of unwanted noise
• Can reduce pollutant emissions of VOCs
• Can reduce moisture content of air and condensation

• Energy used to overcome airflow resistance
• May save energy by preventing fouling and obstruction of
heating and cooling coils and ductwork

• Reduces indoor particle concentrations with indoor or outdoor origin
• Reduces soiling of surfaces
• Filters can be odor sources
• Filters, if wet, can be contaminated microbiologically

• Energy used to evaporate water

• Affects comfort
• Potential source of microbiological and chemical pollutants in the HVAC system
• May lead to condensation and microbiological growth on occupied space surfaces
• Linked to respiratory illnesses from humidifier contaminants
• Possible link to person-to-person respiratory illnesses transmission

• Energy used to transport air

• Allows filtration of recirculated air
• Causes dispersion of indoor pollutants
• Reduces concentrations of indoor pollutants near sources
• Potential source of noise in occupied space

• Energy used to transport air

• Sealing moisture pathways
• Affects pollutant and moisture transport through building envelope, ductwork, and among
rooms
• May reduce or cause moisture problems in building envelope
• Affects infiltration-related drafts and comfort problems
• Can increase likelihood of back drafting of combustion appliances

• Improves HVAC system operation, expected to save
energy

• May improve ventilation, air distribution, thermal comfort, humidity control, and pressure
control
• Lack of maintenance may lead to microbial contamination and combustion safety problems

• Cleaning of coils reduces air pressure drops and
improves heat transfer, potentially reducing HVAC energy
use

• May reduce, or temporarily increase, pollutant emissions from HVAC systems
• Debris, microbiological contamination, and poor draining from cooling coil drain pans are
associated with increased respiratory symptoms

ASHRAE JouRnAl

ashrae.org

Septem ber 2013
ASHRAE Journal - September 2013

Table of Contents for the Digital Edition of ASHRAE Journal - September 2013
