@kevint70 Thanks, that makes sense. My windows do have a slight tint but I'm pretty sure there's no Low-E coating. I think I'll start budgeting for an upgrade in the next couple of years. The comfort and air leakage points you made resonate with me. Appreciate the insight!
This might be a silly question, but here goes: I recently had Low-E windows installed and on some mornings I see condensation on the outside of the glass. It scared me the first time because I thought the seals had failed or something. But it's on the exterior and it dries up once the sun comes out. Is this normal with energy-efficient windows? I never noticed it with my old single-pane windows.
@writer78 Not a silly question at all – I actually called my installer about the exact same thing after our new windows were put in! Exterior condensation on new high-efficiency windows is actually a sign that they’re working well.
What's happening is, at night the outside of the glass can cool down by radiating heat to the night sky (especially with good Low-E coatings, the heat from inside isn't leaking out to warm the outer pane as much). If the outside air is humid (hello, Florida) and the glass surface drops below the dew point, you get dew on the outside of the window.
With old single-panes, you probably had interior condensation in winter because the glass was cold inside. With new double-panes, the inside glass stays much warmer, so no more interior condensation in winter. Instead, the outside of the glass might be a bit cooler than old windows, causing dew on the exterior on cool mornings.
Bottom line: if you see a little exterior dew/condensation, it's normal and actually indicates your windows are insulating properly. As long as it goes away as the day warms up, no need to worry. Just don’t mistake it for moisture between the panes (that would indicate a seal failure).
@history_gandalf Whew, that's a relief. Thanks for explaining it so well! I won't worry about the morning dew on the glass then.
Has anyone here replaced their sliding glass door with an energy-efficient one as part of the project? I have a big old aluminum slider to my patio. It's like a giant energy leak (you can feel the heat coming in and the cold air escaping). I'm already doing the windows, but I'm on the fence about doing the slider at the same time because of cost. Any experiences with upgraded sliders in terms of energy savings or comfort? Do they make as much difference as the windows?
@yoga674 Yes! As I mentioned earlier, we replaced an old single-pane aluminum sliding door with a new impact-rated sliding door (with Low-E glass and argon) when we did our windows. The difference was huge in terms of comfort. Before, on a hot day, if you stood next to that old slider, you'd feel the heat like an oven door was open. The new slider is so much better – the glass stays relatively cool. No more feeling that blast of heat when you walk by it.
It also improved the AC situation in the adjacent room; we used to have to crank the AC to keep our family room comfortable because of all the heat coming through the old door. Now it stays cooler with normal AC settings.
If the slider is old and not insulated, I'd say it's worth replacing if you can budget it. It will likely cost as much as a few windows (our 8-foot slider was about the price of 3 windows, and a 12-foot one can be like 5 windows). But remember it's like a big window. In our case, doing it together made sense because the installers were already there and it was all under one permit.
Energy savings from just the door might not be dramatic on your bill by itself, but comfort-wise it's very noticeable. Also, new sliders have better weatherstripping, so less air leakage too. And if you get one with Low-E, it will cut down on UV fading and glare, just like the windows.
One more thing: the new sliders (at least the one we got) have double-pane tempered glass and a tight seal, so they're a lot quieter and actually more secure (harder to break) than the old single-pane door.
In short, if you can afford to do the door along with the windows, you'll likely be glad you did when that summer sun is baking the side of your house. If not, you can always do it later, but then you'll pay a separate installation trip. For us, bundling it was worth it.
I'm curious about triple-pane windows in Florida. I know up north they sometimes use triple-pane for better insulation, but is anyone here using triple-pane windows? Is it overkill for our climate? Do they help enough with energy or noise to justify the extra cost and weight?
@matthewcoder3090 I looked into triple-pane when I was researching (mostly out of curiosity). The short answer: for Florida's climate, triple-pane is generally overkill for energy efficiency. The extra pane does improve the U-factor a bit, but our bigger issue is solar heat, which Low-E coatings already address very well. You can get a very low SHGC with double-pane + good Low-E. The incremental benefit of a third pane (and possibly krypton gas) is relatively small for the cost.
Triple-pane windows are heavier and more expensive, and not many Florida-oriented manufacturers even offer them (since there's not much demand here). They also might reduce the visible light slightly more (since there's an extra layer of glass).
That said, triple-pane can help with noise reduction a little, and if someone lives right by a highway or airport and really needs quiet, a laminated double-pane (impact glass) or a triple-pane could be considered. But for most homes, a quality double-pane is more than enough.
I ended up with double-pane and have been very satisfied. My house is quiet and cool. If I were in Minnesota or something, I'd consider triple-pane; in Tampa, not so much.
Hey everyone, I haven't checked this thread in a while, but reading through the latest posts and @jmartin52's update, I wanted to share my outcome. I posted earlier about deciding on the high-performance "solar" Low-E glass for my west-facing windows. Well, I went for it and got my windows installed two months ago.
I am happy to report the windows look great and the heat reduction is very real. Those rooms are so much more comfortable in the late afternoon now. Visually, you can't tell the difference in glass unless you're actively looking for a slight reflection. None of my neighbors noticed anything odd about the windows' appearance. Inside, the light is just as bright, but we no longer get that harsh glare. So I'm really glad I chose the better Low-E option.
Thanks to everyone who weighed in – it gave me the confidence to go with the more efficient glass. And as a bonus, I did end up getting a small rebate from Duke Energy (about $200) because I did their free energy audit and the windows qualified. Win-win!
@drummer573106 Awesome, glad to hear it worked out! It's always nice to hear back about the results. Enjoy the cooler rooms!