Keep the hot air out in the summer.
Building interior window insulation panels.
Topher belknap is a fellow member of the midcoast green collaborative here in maine and he came up.
They will stop drafts dust air infiltration.
Push them into the opening inside your existing windows to create an insulating pocket of air.
Energysavr window inserts are effective interior window insulation panels.
Windowtherm insulation panels formerly known as advanced energy panels are interior panels not storm windows and not replacement windows.
Rather they are affordable custom built and environmentally friendly window insulation panels specifically designed to increase your comfort level and save you money.