There’s a plethora of different window options available for consumers these days!! Wood, aluminum clad, to vinyl laminated windows. How do you know what’s the best & the most important features of your new product? If you are doing the work yourself, make sure you find a knowledgeable salesman from the supply company you are dealing with. Start by asking questions about style, function , & energy values. Energy value is one of the most important factors & how the ratings stack up against other offered windows! One other question is do they qualify for the energy tax credit from the government? Yes, this is still available, however the credit is lower than prestimulus levels.
There’s two critical measuring sticks regarding windows & energy. The U-factor measures the non solar heat loss or gain through a window or skylight. The lower the number, the better. U- factor energy ratings for windows are opposite of the r-value used to measure insulation energy values. Think of U-factor as a two way street in that it measures heat gain from outside & heat loss from inside your house. The solar heat gain coefficient measures the solar radiation through a window. Again. the lower number equates to less heat transfered into the inside of your house. The SHGC can be thought of like a shading ability. Check with your supplier to see what climate zone you live in. This will ensure you that your windows meet the energy star standards for your region.
One other thought , think about cleaning windows that are located on the second story height level!