Attic Temperature Vs Outside Temperature

Your insulating and heating cooling the house not the attic.

Attic temperature vs outside temperature.

What should be the difference between outside inside temperature of an attic on a summer day versus a winter day. For an indoor temperature of 68 f and an outdoor temperature of 8 f the temperature at the interface between the batt and the foam will be 27 f effect of indoor and outdoor air films is omitted. 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.

Ideally you don t want it any hotter than it is outside but reality generally prevent this from happening. Attics can reach temperatures of 150 to 160 degrees f during a summer day although outside air temperatures are only 95 to 97 degrees f. Warner is right that the attic should be close to the outside temp. What should the attic temperature be relative to the outside and house temperatures assuming a new supposedly well insulated house.

I have recently added a ridge vent to my roof and have also been taking temperature readings. A check the temperature an hour before sunrise. The technique applies to any number of component layers in an assembly. I hit 130 degrees in my attic when the outside temperature was.

Should there be a difference between a 78 degree day and a 98 degree day. Table 1 shows the calculation for the example in figure 1. Simply undertstand that the insulation in your inner envelope ceiling attic floor must insulate the inner envelope of your house living area against whatever temp is in your attic.