Hot summers. Freezing winters. Lots of drastic temp swings in the spring.

LoE-270 has a visible light transmission of 70%.

LoE-366 has a visible light transmission of 66%.

But with just a loss of 4% of visible light you gain:

U Factor: LoE-270 is .37, LoE-366 is .24

Solar Heat Gain Coefficient (SHGC): LoE-270 is .37, LoE-366 is .27

All values are for the glass ONLY, the whole window will carry different values.

Unless you are trying to gain more heat through passive solar heating in the winter, the 366 is a great choice. I did a simple 40"x78" casement and the upcharge was about $40.

They also offer a LoE-340 glass. This is the "Turtle Glass" from coastal areas and significantly reduces the visible light (40%). I only use this as an alternative to tinted glass. "Turtle Glass" is required to prevent hatching turtle from going toward shore vs. the ocean. Make sure you don't get the wrong LoE-3!

Excellent choice in window brand!

Normally in your climate, Low-e 2 is all you need. Dealer may have quoted Low-e 3 because you mentioned your art collection. It does give added UV protection but is darker etc. as mentioned.

+1 to the previous comments. Arkansas is still a Heating Degree Day dominated climate. While the Low-e 3 will further mitigate summer radiant heat issues, you will be doing so at the expense of some free winter time heat. You definitely should not do so under the deck.

Climate Zone Data

Yes you are correct. I had used my power-point printout from a recent Cardinal Glass training in Warroad for the numbers, sorry! This is from the Cardinal Glass website:

Thank you for the correction!

Here's the Cardinal direct link Tri-County.

Cardinal Glass Performance Stats