Frequently Asked Questions on Efficient Attics
Aren't the most airtight homes the most energy efficient?
No. In fact, a certain amount of air transfer is necessary to prevent
indoor air quality, humidity and other issues from becoming problems in
your home. With efficient attics, ventilation and air transfer is done
in a very controlled and designed manner. In inefficient homes, more air
could be leaking than you want. Sealing unwanted air leaks is vital to
a homes energy efficiency. However, controlled ventilation in your attic
is also very necessary.
How does attic ventilation improve energy efficiency?
Ventilation promotes a cooler attic in the summer and a drier attic in
the winter. By not allowing as much heated air to reside in your attic,
a good ventilation system will help keep the rest of the house cooler
with less energy usage. In cold months, ventilation prevents moisture
build-up in the attic. As warm, moist air rises into a cold attic, it
can condense under the roof deck, causing the decking and shingles to
distort and deteriorate. Excessive heat and excessive moisture can both
lead to serious roof damage. In addition, family valuables can become
damaged due to extreme heat and/or moisture.
Where does moisture in the winter come from?
Many household activities naturally create moisture, such as showers,
laundering and cooking. These activities can release as much as three
to five gallons of water vapor a day. Water vapor rises. If this vapor
becomes trapped in the attic, it can cause major damage to your roof decking,
shingles and personal belongings.
What kind of ventilation system do you recommend?
Solutions vary depending on many aspects in the home. The most common
solution employs a ridge vent at the peak of the roof plus vented soffits
under the eaves. However, depending upon the structure of your roof, other
systems may be recommended, such as wind turbines, air hawks, and a variety
of powered and solar-powered vents.