I concur with the comments regarding Martin Muller with Double-Hung. Though not inexpensive (we paid about $350 a window but that included "unsticking", new weights, ropes, etc.) the price was worth it. Martin was prompt, courteous, tidy and on budget. Its amazing the difference "working" double hung windows can make with regard to the air flow throughout your home. For those unfamiliar with the term "double hung" it refers two windows, typically older wood windows, where both the top and bottom halves of the window can move up and down. This allows for hot air to escape at the top and cooler air to enter at the bottom. The solution is much more energy efficient then air conditioning and there's no noise or big box sitting in your window.