In the garage is an access door to the attic.
Attic vent open in summer.
When the attic becomes part of the home to be heated and cooled open wall gable vents and roof vents are no longer feasible but the underside of the roof the sheathing and rafters can still get.
During this brutally hot summer of 2012 i ve left the garage access door open and it dropped the temperature in the attic substantially.
Some can have manual switches while others use a thermostat to turn them on and off automatically.
Also you place it on the roof top or gable mounted.
The narrow soffit slits allow air to flow freely into your attic.
Effective attic ventilation systems reduce damaging heat and moisture in your attic promote energy efficiency by helping to reduce the load on your air conditioner in the summer and also reduce the risk of ice dam formation on your roof.
During the summer this leads to the hot air from the attic seeking out the cooler conditioned floors below.
They need to be open in the summer.
This insulation resists the heat from the terrace to pass it directly to the living room.
Insulation at least r 38 or more is there for heating and cooling.
Since attics are often under insulated poorly sealed and poorly ventilated the temperature environment can be drastically different in an attic than in the rest of the home.
The house has roof gable and soffit vents.
Attic fans come with different models.
Although air should circulate year round through the attic your house will probably be more comfortable if you cover the foundation vents in the winter.
One last thought attic ventilation is not there to get rid of heat it is there to get rid of excess moisture accumulating from the home.
Typically these devices are used in summer when the temperatures are high exceeding 49 degrees celsius.
These are exhaust vents that are installed on the ridge of your roof i e.
It can do both.
Your attic acts as an insulation between the terrace and the living room.
The airflow pushes the hot air out which is exactly what you need to keep your attic cool during the summer.
Best ventilation is open soffit venting to a open vented ridge vent.
Ridge vents are available in a series of pieces or as one long piece.
I think you should do the reverse one.
Hot air is rising so is it smart to open the attic stairs in summer.