Home Energy Health Assessment - Focus
Points
Building envelope
The shell or “building envelope” of a home is designed to
protect occupants from outdoor elements. Unfortunately, most
existing and older homes have building envelope air leakage,
known as infiltration, through windows, doors, walls, floors and
ceilings, as well as attics and crawl spaces. This leakage
allows air, moisture and outdoor pollutants to penetrate indoors
making the home uncomfortable and causing high energy bills.
Studies show that 35 to 40% of heating and cooling costs pay for
infiltration alone.
HVAC
Duct System
Leaky ducts are a leading cause of poor indoor air quality
as pollutants are drawn into the system, re-circulated and
distributed throughout the house through the heating and
cooling units. Leaky ducts also contribute significantly to
a home’s energy loss. Homeowners lose 10% to 30% of heating
and cooling energy through leaky ducts. HVAC systems leak at
the air handler and plenum seams, and at the duct-to-vent
joints. Contractors use tape, which degrades with time.
Our team uses the Duct Blaster® equipment to pinpoint
leakages in the HVAC ductwork with a theatrical smoke
machine to dramatically highlight any imperfections or holes
in the system. We can test your system with Duct Blaster to
show total leakage, then pinpoint the leaks with smoke
testing and tactile inspection. We will reseal your system
with bucket mastic and retest with Duct Blaster® to ensure
your duct leakage is minimal. Learn more
Equipment size, layout, efficiency, and fresh air intake
levels
Accurate sizing of HVAC equipment is crucial to a home’s
energy efficiency. A well-sealed building with properly
installed duct work may qualify for a smaller, less
expensive unit. Our home energy modeling software will help
you determine which HVAC equipment is best for your home.
Insulation
Insulation is only effective if it is a continuous thermal
barrier, with no air gaps or voids, and is in continuous contact
with the air barrier or building envelope. Wall insulation, to
have the maximum effect, must be encapsulated on all six sides
by air barrier backing, such as a stud cavity. One reason why
bonus rooms are so notoriously hot and cold is because there is
no backing on the attic side of the insulation batts in the
kneewalls.
Batt insulation is very often improperly installed, stuffed into
stud cavities, with gaps and voids between the batt and the
drywall. When insulation is compressed, it loses R value. Batts
are often stuffed in front of or behind piping and wiring in
stud cavities, compressing the insulation and leaving an air
gap.
Moisture and mold
Attic
An effective thermal barrier can prevent
humid outside air infiltration. If there are flaws in that
barrier, breaks and leaks, this moist air can be drawn into
the conditioned space. Negative pressures from an imbalanced
ventilation system can accelerate this infiltration. This
water vapor will condense on any surface below dew point,
such as cold spots, caused by breaks in the insulation.
Moisture build up like this will breed mold and mildew. (not
sure how to explain about attic moisture; soffit to ridge
vent airflow is designed to cool roof deck) During the
winter months, if warm air leaks from the home, it will
condense on the cool attic sheathing and create an
environment for mold.
Crawl space
Crawl space vents are supposed to keep the space ventilated
and dry, but in our mixed-humid climate, they work the
opposite. Humid air from the outside is drawn in and
condenses on surfaces that are below the dew point (floor
joists and rimbands, etc). This moisture promotes mold
growth. If there are leaks in the crawlspace return ducts,
mold spores can be drawn into the ventilation system. If
that system is not pressure balanced, negative pressures in
the main return area can pull moldy, crawlspace air into the
living space through air leaks in the framed floor. Our
Sealed Healthy Crawlspace can prevent moisture from
infiltrating infiltration.
Room Imbalances
Pressure and indoor drafts
Bedrooms and bathrooms usually have a forced air supply but
no return path except through the door. If bedroom and
bathroom doors are shut pressures build, causing low
pressures in the main central area. These negative pressures
in the central area can multiply create a vacuum effect
which pulls air infiltration through the adjacent building
shell, from the garage, attic, crawl space, around windows
and doors. In the winter this would be cold and drafty air,
in summer, hot and humid.
Temperature
Hot and cold spots in walls, ceilings, and floors radiate
uncomfortable temperatures. They are caused by improper
framing-breaks in the air barrier, missing or improperly
installed insulation.
Combustion
appliances
Combustion appliances need fuel and air to operate properly.
Room pressure imbalances in a house can quickly lead to
dangerous consequences resulting in the back drafting of a hot
water heater or gas furnace.
Carbon monoxide levels
Carbon monoxide is a natural byproduct of the combustion fuel
process. It’s important that CO levels be controlled and
appliances properly vented to ensure the safety and well-being
of your family.
Indoor air pollutants
Toxins are commonly found in our environment in the form of
mold, pollen, carbon monoxide, pesticides, chemicals and
fertilizers. Controlling these pollutants inside homes is the
key to improving indoor air quality (IAQ) levels and your
family’s health.
Water usage levels
The easiest and most cost-effective way to decrease your
family’s water consumption is to install low-flow shower heads
and faucets throughout your home.
Rainwater
management site inspection
Rainwater drainage can rot roof sections where rooflines join at
right angles if they are not properly flashed. Grading must
divert stormwater away from house foundation. Foundation drains
should be installed (separately from gutter drain lines) around
the perimeter of the house to move groundwater away from the
foundation.
