Will Leaving my Garage door open affect the indoor temperature?
This is a tricky and complicated question to answer and comes up a lot in the summertime months.
Leaving your Garage door open can affect the temperatures inside your home, but how depends on your setup of your garage and the layout of your homes interior.
If your garage is properly ventilated, or better yet it is air conditioned, a closed door policy is best to avoid letting the hot air in.
If your garage is NOT properly ventilated or climate controlled, as is often the case, a hot enough day can turn the space can turn the space into a convection oven.
This can be problematic, especially if your home has rooms over the garage, as this heat will escape upwards and into your home, exacerbating the all too common issue of a perpetually hotter 2nd floor.
In the latter case, cracking the garage door every once and while to air it out can help lessen the effect, but at the end of the day , a properly conditioned or ventilated garage is ideal.