Yep, "lite" is the correct spelling/usage for a window glass pane.

And yep, laminated glass does block 99% (or a little bit better) of UV light from entering your home thru the windows but keep in mind that UV blocking isnÂt the same as keeping heat out of your home; consider UV blocking to be a side benefit.

In terms of heat transfer, there are two aspects to consider - U-value and Solar Heat Gain Coefficient or SHGC.

In the environment that you are building, SHCG is more of a consideration than is U-value. In a nutshell, U-value is concerned with far infrared heat and SHGC is concerned with near infrared heat. Near, or shortwave, infrared is direct solar gain. This is what you feel when standing directly in a sunbeam. This is primarily what you need to stop from coming into your home in the Virgin Islands.

Heat is transferred in three ways, conduction, radiation, and convection.

Conduction is the transfer of heat energy thru a substance by atomic or molecular interactions - or, more simply put - when you touch the aluminum handle of a frying pan on the stove and the handle is hot to the touch, then you are experiencing conductive heat transfer.

Convection is transfer of heat energy thru mass motion of a fluid (yes, air is a fluid) resulting from the movement of the heated fluid from the source of the heat. An example is warm air rising and displacing cooler air which then falls and warms up and then rises replacingÂetc.

Radiation is heat transfer by the emission of electromagnetic waves which carry energy away from the emitting object. In other words, when you stand in direct sunlight and you become warm, you are being warmed by radiation.

About 2/3's of the heat energy that enters thru your windows does so as radiation. The remaining 1/3 is conduction. By limiting direct radiant solar gain (SHGC) you will be affecting the significant portion of unwanted heat from entering your home.

Your current Schuco windows with dual pane and LowE and argon fill are designed to limit heat transfer including radiant (LowE coating), conductive (air space with argon fill), near infrared (LowE coating), and far infrared (LowE and airspace with argon fill). Or, more simply, your current windows are designed to perform both winter and summer. They keep heat out and they keep heat in  depending on the season and the requirement.

In your new environment keeping heat out is what really matters  not so much keeping it in.

As you may have already noticed, it is the LowE coating that limits the direct solar gain that will be warming the inside of your home when the windows are closed. And to finally address your question directly, if you were to opt for a single laminated lite, rather than the IG units of your current windows, is it possible to get the same level of performance that you get with the IG windows?

Yes and noÂyou wonÂt get quite the same overall performance with a single laminated lite that you do with an IG because with a single laminated lite you donÂt get the U-value advantage that you get with the IG Â but as mentioned, you probably donÂt need it in the Virgin Islands.

You can get some very nice SHGC numbers though when using a single laminated lite with the coating laminated to the interior of the laminated "sandwich". SHGC numbers that are very close to those that you can get with a dual pane IG.

A number of the laminated glass manufacturers laminate glass with softcoat LowE between the lites. Also, there are some window manufacturers who offer tinted or reflective hardcoat LowE coatings that would be on the exterior of the glass.

The primary positive of the exterior hardcoat is that it actually blocks a bit more solar gain that the internalized softcoat. The negative is that being highly reflective  and often tinted  in some cases it can look like you have colored mirrors in your windows. You can often see this mirrored effect in high-rise buildings that have reflective coatings.

The softcoat LowE will be much more color neutral  even unnoticeable, depending on the coating  but the SHGC may be a bit less than the exterior hardcoat performance.

There are two primary products available in laminated glass  Polyvinyl Butyral or PVB, and Sentry Glass Plus or SGP.

Another little interesting fact concerning your question is that the largest manufacturer of residential LowE coatings in the world (who also happens to have a laminating division), does not offer a PVB laminate with an internal LowE coating. They do laminate a LowE coating inside with SGP interlayer though - and which is readily available in a monolithic version from several window manufacturers.

What is interesting is that LowE coatings tend to corrode when exposed to moisture. PVB is very hygroscopic in the right environment whereas SGP doesnÂt seem to absorb moisture nearly as much  so one has to wonder if there is concern (with at least one company) that placing a LowE coating between against a PVB interlayer could eventually be a problem? While they are apparently happy using SGP against their LowE coatings? Something to consider...

Okay, this is really long (typical), but I have attempted to offer a bit of background rather than a simple "yes/no" so that when you are chatting with window / contractor / designer folks you will have a better understanding of how these things work.

Please feel free to ask more questions if you have some (and after this I suspect that you will)Â

Oberon Thanks! I will have to digest the above, but it is just what I needed. I also gathered from your other posts that I need to be worried about air infiltration just as much as design pressure...especially since the on-island window manufacturers may have mostly been putting them in non-AC homes and wouldn't care much about air infiltration.

It is interesting they are very pro-wood and anti-aluminum and anti-vinyl...on the latter, the theory being that your windows will suffer environmental damage no matter what, it is better to see your paint or varnish bubbling than to have a wall-full of stucco fall off below a window due to infiltration under the vinyl.

I always enjoy the fact that glass is a liquid too.

Good morning,

My answer did go pretty far in depth, but hopefully that long answer gives some measure of useable information when you are chatting with the builder.

So far as the choice of wood, vinyl, aluminum it is really personal preference as long as you go for quality and service. I might alos suggest that you look into fiberglass sash/frame material. Fiberglass might be a very nice choice where you are building.

There is a very short, but excellent thread about "unhappy with vinyl" that addresses the quality issue. Like anything else, purchasing (and in the case of windows - installing) quality is often much less expensive than buying mediocre - and it is often not entirely a price issue.

If you want wood windows then I would say go for it - again keeping in mind that you want a very high quality product. If you prefer vinyl or aluminum, then find the window that you want and go with it.

I suspect that the builder's concern over long-term environmental performance of one product over another is much more personal preference (or prejudice) than verifiable fact.

One of the interesting things about glass is that it has attributes of both a liquid and of a solid. Even within the heavy-duty research community there is disagreement as to whether glass should be classed as a liquid or as a solid.

Some research folks refer to glass as a supercooled liquid - which is correct to the definition - while others refer to glass as an amorphous solid - which is also true and correct to the definition.

Solids can be described as having ordered or crystalline molecular structure tightly bound in a regular lattice...

whereas in liquids (or fluids) the molecules are disordered and are not rigidly bound.

But glass molecules are disordered and are rigidly bound - again attributes of both liquid and solid.

Some folks will suggest that glass is neither liquid or solid but is another state entirely - although I think that most research folks probably don't agree with that definition - but it is a cool idea nonetheless.

Personally, I am with you and I see glass as a super-cooled liquid. But, we all have our opinions as they say!

Excellent tip about fiberglass windows, I have never heard of them, will start researching. Since I have nice wood-grain fiberglass doors I suppose I can get nice wood grain fiberglass windows. I was not happy with the idea of exterior wood but I understand the concept of 'pick your problem'. I think you are 100% correct that construction-related people on the island will have obvious economic biases (like anywhere), the difference being that they can scare you into believing them because of the unique attributes of the climate and topography about which they supposedly know everything and you certainly know almost nothing. On the other hand I have done plenty of remodeling and people working for me ALL say "gee we never tried that/did it that way/used that product before but it worked" so I just have to trust that I can make sensible decisions even if they are not the typical decisions. I'm off to read the vinyl thread, THANKS.