Configuring Attic Ventilation Based On Outside Temperture

Attic moisture usually appears because of condensation.

Configuring attic ventilation based on outside temperture.

As the florida study found attic ventilation only made about a 10 degree difference to attic temperature maximum. Luckily my wife and i were upstairs and hear the rafters crackling looked outside and saw the wall of fire and got our. Roof shingle temperatures will be higher during no wind conditions leading to a higher heat load on the attic. So my house burned down a couple of years ago.

Therefore the greatest need for attic ventilation is when there is little wind pressure to force air in and out of the attic. Do you have a chart showing temp changes in the attic using a vent cap on a roof. Calculations indicate that on a july day in texas a ventilation rate of one air change per minute for a typical attic using 95 degree f air will lower the peak attic temperature to about 101 degrees f. Lowering the temperature in the attic can lower the temperature in the rest of the home reducing the amount of time the home s air conditioner spends running.

Example if the outside air temp is 90 95 100 105 ect degrees what is the air temp in the attic. If you have high temperatures and high humidity in your attic then you may also have a problem with mold. Then stack effect is the prime air mover driven by the attic to outside air temperature difference. Attic fans draw cooler outside air into the hot attic area through attic vents located either on the roof or on the wall near the gable to reduce the space s temperature.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Temperature attic temperature depends on the outside temperature and it also depends if your house is insulated. Ventilation is another key factor. If your attic soars above 100 degrees and reaches the 150 mark its time to consult.

Providing half air change per minute will lower the temperature to about 106 degrees f. The fire started on an outside wall went up the wall and into the attic space spread across the entire house in the attic with no smoke coming into the house until the ceiling was about to collapse which was far too late. A standard powered exhaust vent turns on when the temperature inside the attic.