As part of a major remodel, we are installing vinyl replacement windows throughout the house. I have several estimates, but am getting different information from the different contractors. One company is telling me that the windows with the spring loaded system is best, while another is telling me that the ballast systems are better. I did notice on the spring loaded demo window that when I raised the window, it slid back down a quarter of inch. My wife says it possibly because the window has been used for so demos.

My first question, which is better spring or ballast windows?

A second question is what is the difference between LowE and LowE2? Is it worth paying extra money for the LowE2?

Thanks in advance for any information you can give.

you answered your question about the balance. If the window was sliding down a little because it was used. What is to say your not going to use it youself? Hmmm makes you think.
As far as what works best depends on the manufacture of the window and what kind of warranty they have on their balance system.
Also the operation of the window has a lot to do with the quality of the installation.
Low-E2 glass has an additional film that they put between the glass panes which increases the performance of the glass. This is important if you live in real hot or real cold areas and you have a lot of large glass panels that simply cannot be covered with drapes or window treatments. If you live in a typical home style with normal sized windows that can be closed up both during the hot summer months and cold winter nights. I am not sure I would go for the extra bucks for this upgrade in glass.

LowE coating is designed to block heat transfer. LowE2 coating is designed to block heat transfer. Doesn't sound like much of a difference unless you understand the "type" of heat that each coating blocks.

There are two primary types of LowE coatings on the market - hard coat and soft coat. LowE can be either a hard coat of a soft coat. LowE2, on the other hand, is only available as a soft coat.

The primary heat blocking ingredient of a hard coat LowE is tin oxide. The primary heat blocking ingredient of a soft coat LowE is silver. Silver works much better than tin oxide in that application.

LowE coatings are designed to block far infrared heat, but they do nothing for near infrared heat - or direct solar heat gain.

This makes a LowE coating a good choice for someone who wants maximum solar heat gain (near infrared), but who also wants to retain that heat as well as containing the heat from their heating system (far infrared) in their home.

LowE2 coatings are designed to block both near infrared and far infrared, so that LowE2 coatings block both direct solar gain as well as heat from other sources.

LowE2 is not the best product if someone wants passive solar heat gain, but it is better at blocking heat (in general) than either hard coat or soft coat LowE coatings.

Whereas the soft coat LowE coating contains a single layer of silver - as well as several layers of other metals and metallic oxides - a LowE2 coating contains two layers of silver - again as well as other layers of metals and metallic oxides. This extra layer of silver - working in concert with the other layers of metals and metallic oxides - is why the LowE2 can block both near and far infrared energy.

Thanks to both of you for your replies, they were very informative and helpful. We have signed the contract for our window replacement and hopefully have made the right decision.

I have experienced the same problem,this post is also useful to me!thank you all.