I am looking to buy a window insulation kit. How much temperature increase would it cause? I live in an area where it goes 45 degrees Fahrenheit during the winters.
Since the temperature is controlled by the thermostat, this product will not cause any temperature increase at all.
This product is a window insulation kit and, if properly installed, should reduce heat (not temperature) loss through the window. The net result should be a reduction in energy cost through the window.
The amount of heat loss prevented is quite difficult to determine in advance as it depends on a number of factors. The best way is to use an infrared heat sensor camera before and after installation and one on of the tools that come with those types of camera to estimate the heat loss reduction.