I spent a lot of money recently on insulation. This was not for my house itself. It was just for the windows. The reason I had to buy all this insulation was because I was needing to put in a few window air conditioning units. I chose to get rid of my central heating and air conditioning system recently because it just cost too much money to run. With the rising cost of energy bills, running a central heating and air conditioning system was just a killer on my bank account. There was really no energy saving tip in the world that could have made me keep my central heating and air conditioning. I had read about getting space heaters and ductless mini split air conditioning systems. However I would have had to spend a small fortune just to have enough of those to be able to heat and cool my entire home. So I got a hot water boiler for my heating and I am putting in these window air conditioning units for my cooling. The insulation is needed because the windows are slightly larger than the actual window air conditioning units. By putting the insulation in it makes it not only so the window air conditioning unit will fit into place. But it also keeps the nice air conditioned cool air going strong throughout all the rooms in my house that I am placing these window air conditioning units in. The window air conditioning units really do the job great in cooling my home. I can not believe that I did not think of this sooner.