I have Pella low-E glass windows, approximately 40 windows. To have them professionally cleaned is costing approximately $400. Due to the low-E glass they are difficult to clean. When I do it, if the sun shines in they look like they haven't been cleaned in ten years. Any suggestions would be welcomed. I hate to keep throwing away money on something that I could easily do if I could get good results.
There are s few positives to paying a professional to clean your windows, one is the transferring of risk from you to a professional.
If you are not getting the results you are wanting and are using the right cleaning mixture there might be a few reasons.
1. Make sure you are using enough cleaner to suspend the particulate and film build-up. It might be necessary to clean a few times before buffing to a streak-free shine.
2. Degree of difficulty increases as temperatures gets warmer, cleaning in direct sunlight takes a lot of practice, patience and personal hydration.
Micro-fiber rags are the best choice. There are different types though, some are very absorbent and others are not absorbent at all. Use the absorbent ones for cleaning and the non-absorbent for polishing at the end.
Hope this is helpful.
Is this low-E on a glass panel that you can take out with clips? If so, you may have damaged the low-E coating if you are using products such as Windex to clean it. Cleaners that are ammonia- or alcohol based can cause permanent damage. Pella recommends a vinegar-based solution.
If the low-E glass is not removable then you aren't actually cleaning the low-E coating. When two pieces of glass are sealed together, the low-E is on the interior side of the glass and you wouldn't be able to touch it.
Owner's manual can be found here (the first link in the "Support Section"):
Try spraying with white vinegar and water mixture, and use a squeegee.
I don't have Pella but a less expensive brand of low E glass windows. I have found using a microfiber cloth with only water works the best and lasts the longest of anything I have tried and much cheaper than hiring a cleaning company. I use one cloth to wash and one to dry.