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Fact vs. Fiction...
Common Myths about our Homes
Myth #1: Dry indoor air in the winter is caused by forced air
heating systems and a humidifier is the answer.
Fact: Dry indoor air is caused by thousands of tiny holes in
the outside walls and ceiling of your house. Seal the holes,
and your indoor relative humidity is usually quite comfortable
given normal levels of cooking, cleaning and bathing - without
additional humidification. In fact, additional humidification
can lead to condensation in the exterior walls and microbial
growth in the ducts.
Myth #2: Fiberglass batts are an effective insulation product
for walls and ceilings.
Fact: Fiberglass batts are almost impossible to install without
leaving compressions, gaps and voids, which cause extensive
heat loss. One of the reasons fiberglass is so cheap is because
installations
are usually rushed. Also, fiberglass offers virtually no
resistance to air flow leading to extensive heat loss through
leaky exterior
walls.
Myth #3: Traditional
framing at 16” OC (on center) is better
than 24” OC framing because you get a stronger house,
and there are no unsightly waves in the sheetrock on the
exterior walls.
Fact: 16” OC framing with 2x4’s has been the standard
for years but puts more wood in the wall (up to 25% of the wall),
and wood is a poor insulator. 24” OC framing with 2x6’s
produces a very strong house and leaves more room for insulation.
Upgrading to 5/8” sheetrock (instead of ½”)
will prevent waving and reduce sound transmission.
Myth #4: There is nothing wrong with the standard practice
of running air ducts in unconditioned basements and attics.
Fact: Testing reveals that forced air systems in the
northeast typically leak 20-40% of the air they carry.
This leads
to much wasted energy, if the ducts are outside the conditioned
envelope,
and can lead to the distribution of insulation particles,
moisture, radon, and mold spores throughout the house.
Myth #5: Natural draft water heaters can be safely used
in any home.
Fact: The safety of natural draft combustion appliances
is dependent upon the air pressure relationships within
the
house and between
the indoors and outdoors. These pressure relationships
can be dramatically affected by range hoods, dryers,
and bath
fans.
Every combustion device should have a dedicated source
of combustion air to prevent the backdrafting of combustion
by-products, such
as carbon monoxide, into the living environment.
Myth #6: An air-tight home is dangerous because it
creates moisture problems and can lead to sick building
syndrome.
Fact: An air-tight home eliminates uncontrolled air
infiltration into the exterior walls, which is the
real cause of both
moisture and microbial problems. Only in an air-tight
home are the occupants
in control of the air, heat, and moisture flows,
allowing for the controlled introduction of fresh
air 24/7/365.
A home with
leaky exterior walls will allow excessive uncontrolled
air infiltration in the winter, leading to heat loss
and dry
air. In the summer,
even leaky exterior walls will not admit adequate
fresh ventilation air (smaller temperature differences
than
in the winter create
lower air pressure differences, with little air leakage
through the outside walls), contributing to stale
air and the accumulation
of indoor contaminants.
Myth #7: Oversized
heating and cooling equipment is better for your home because
it gives you reserve
capacity.
Fact: Oversized
heating and cooling equipment will not be able
to properly control the temperature
of the conditioned
space
because it produces more heating and cooling than
the home needs. The unit will cycle on and off
frequently (short
cycle),
continually
overshooting the desired set points, and costing
more
to operate. Short cycling on the cooling side reduces
the
unit’s
ability to remove moisture, leading to air that
is both cold and damp.
Myth #8: Replacing your single-glazed windows with
double-glazed can save you up to 50% of your
heating bill.
Fact: Your savings will depend on the amount
of glass surface area in your home in relation
to
the size
of your home.
A typical home will see savings more like 20%.
If the windows were poorly
installed, then air infiltration around the windows
can be
a significant energy loss, and proper air sealing
will save more
energy.
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