How Much Hotter Is An Attic Than Outside

During the summer this leads to the hot air from the attic seeking out the cooler conditioned floors below.

How much hotter is an attic than outside.

Here is statistics over the same period of the temperature rh and dewpoint of my unconditioned attic. At night outside temperatures have dropped to 70 f but after leaving windows open all night the indoor temperature is still at about 79 f. Ideal attic temperatures shouldn t be more than 10 to 20 degrees hotter than outside temperatures. A good sign is when you open your attic in the winter and you don t see any frost on the nails poking through.

The frost is frozen condensation from the warm air meeting the cold air and not ventilating if that. Under side of roof deck is not much warmer than the attic air temperature. Now if the ridge vent is only partial or if the attic air temperature is excessive 20 degrees higher than the outside air fans may prove beneficial pick the right fan. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Warner is right that the attic should be close to the outside temp. This is most notable in the case of attics. Your insulating and heating cooling the house not the attic. Intake vents located at the lowest part of the roof under the eaves allow cool.

All the heat stored in the insulation filters into the house rather than venting to the outside. 105 in the hot summer in the south if outside temp 85 90 35 40 in the dead of winter in the south if outside temp 20 30. Watson s hunch is there isn t enough attic ventilation. If your attic soars above 100 degrees and reaches the 150 mark its time to consult.

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.