The ideal temperature outside is at least 5 degrees fahrenheit below the desired indoor temperature.
Attic cooler than house.
Attic fansare most effectiveduring the hottest part of the day and they are usually controlled by a timer thermostat 2 or humidistat.
Insulation can only slow and not stop the energy transfer.
So everything else being equal any house would benefit from a cooler attic.
If you ve got an older home or poorly installed insulation there s a good chance upping your r value and air sealing in the attic will make your upstairs cooler and more comfortable in summer.
But other factors impact this sort of thing too.
Attic fans perform this ventilation by pushing hot air out into the environment while also pulling fresh cool air into the attic.
Maybe but not always.
The result is a cooler attic space with plenty of air exchange.
In many houses it is impractical to increase the insulation in the attic.
In contrast whole house fansare most effective in the cooler temperatures of the evening and early morning.
Which way does your house face.
In summer the ideal is to have lots of air movement so the attic is as cool as possible.
Proper attic ventilation has year round benefits.
The third graph shows attic temperatures from the middle of the attic for several different types of roofing as well as a sealed attic.