Whole-home energy efficiency and indoor comfort rely on the cooperation of three major systems: roof, attic, and ventilation. Air sealing is also an essential part of that equation. While many homeowners know the importance of a well-maintained roof and updated insulation, less pay attention to whether or not their home is well insulated.
Importance Of Ventilation In The Attic
Ventilation includes the process of moving stale or warm air out of the attic while moving fresh air back in. Exhaust systems move air out of the home; air intake systems bring fresh air into the attic.
Higher energy consumption and elevated utility bills
More frequent insulation and roofing repairs/replacement
Vulnerability to mold, mildew, and structural rot
Poor indoor air quality
A professional attic inspection determines whether or not your home is properly ventilated. We’ll also provide a list of any red flags indicating your ventilation system needs repairs, replacement, or updating.
Different Types Of Attic Ventilation
Attic ventilation is divided into two separate categories: active and passive.
Active ventilation
Most attic ventilation occurs using active ventilation, mechanically moving stale or hot attic air outdoors while sucking fresh air into the space. Some ventilation systems require a power source of some type. Others operate via the "hot air rises" (convection) premise, so warm air rises up and is forced through the attic ventilation system.
Different types of active attic ventilation are:
Solar vents. If energy efficiency is a priority for you, speak to a licensed attic professional about solar power ventilation that uses the sun’s power to run the vents. If your home gets lots of western/southern exposure or tends to be hot during the day, these may not be the best option. They don’t run when charging, which may elevate AC use to maintain desired thermostat settings. However, if you live in an area with dappled sunlight with an efficiently insulated home, they can save you money.
Power vents. These vents use a small amount of electricity to suck hot air out of the attic when temperatures exceed a certain point. While solar vents are more efficient for homes with a mix of sun/shade and are designed to remain warm-to-cool, homes in full sun or that run hot benefit from the continuous ventilation of hot air provided by power vents.
Turbine vents. Also called “whirly birds,” turbine vents rely on convection (hot air moving upward). Warm air rises up and spins the turbine on its way out. That creates a small suction effect, encouraging warm air to flow upwards even on the stillest, wind-free days. When installed correctly, turbine vents are effective, completely circulating air through the attic as many as 10 to 12 times per hour. While there are visible slats, turbine vent design angles prevent rain, debris, or insects from getting in.
Ridge vents with a baffle. Ridge vents are part of a roof design and are a popular option for homeowners desiring to keep vents as invisible as possible. They are installed across the entire ridge of a roof. If they have a baffle, air channels through them, and they are the type of roof ventilation we call “active.” Ridge vents without a baffle are called “passive.” If you ridge vents, have a roofing contractor confirm they’ve been installed with a filter. Otherwise, they allow insects, dirt, and other debris to settle in the attic.
Passive attic ventilation types
Passive attic ventilation doesn’t rely on any power source or air movement. Rather, they sit in their (hopefully) well-chosen spot to allow hot air to escape on its own. They are effective to a point, but if your home remains consistently warm or humid during late-spring to early-fall months, it could be a sign you need to add active ventilation options.
Examples of this type of attic ventilation are:
Static vents. These look like boxes on the roof. Their screened/filtered openings allow hot air out via convection.
Ridge vents without a baffle. Like static vents, ridge vents without a baffle have slits that allow hot air out. However, these also create an entryway for pests and debris.
Gable end vents. Installed on the exterior wall of an attic below where the two slopes of a roof meet, gable end vents rely on wind to move air inside and out of the attic. On still days, gable end vents are not an effective means of attic ventilation.
Schedule An Inspection To Assess Attic Ventilation
Suspect your attic ventilation system isn’t up to par? Schedule an inspection with Attic Solutions (510) 500-5007. A professional inspection will identify any holes in your attic’s energy efficiency systems. Any work we are unable to perform results in providing a list of local, licensed roofing contractors we trust.
