Best Windows for Florida Heat? Seeking Advice & Experiences (Tampa Bay Area)

@jmartin52 Welcome to the forums! I'm also in the Tampa Bay area (Clearwater) and went through a similar window replacement last year. Our home had those old aluminum single-pane sliders too, and replacing them made a huge difference.
We chose vinyl frame, double-pane windows with a Low-E coating and argon gas fill. Specifically, we went with a local company (Karoly Windows) for installation, and they used custom windows from PGT (a popular Florida window manufacturer). The Low-E glass they provided has a high-performance coating (I think it's a double or triple layer Low-E), and argon gas between the panes. All our new windows are Energy Star rated for the southern climate.

Energy savings & comfort: After installation, our energy bill dropped by around 15%. It went from about $250 in the summer to roughly $210–$220 on average. The house is noticeably cooler in the afternoons. We have a lot of west-facing glass, and before, you could feel the heat radiating through. Now with the Low-E glass, that radiant heat is way less. Our A/C still runs a lot (Florida, haha), but it definitely cycles off more often than it used to. We also noticed the home is quieter; the new double-pane windows cut out a lot of outside noise (bonus!).

Cost: We had 10 windows replaced. The cost was about $9,500 total, which was mid-range among the quotes we got. Karoly Windows wasn't the cheapest quote, but they had a great reputation and we’re glad we went with them – the installation was smooth and the quality of work was top-notch. No more drafts around the frames and no leaks during rainstorms.

One year later, we have no regrets. The vinyl frames have held up perfectly so far (no warping or discoloration). And the Low-E/argon combo really seems to work for our climate – our living room doesn't turn into an oven at 4 PM anymore. 😁

So based on my experience, I'd recommend: go with double-pane vinyl windows with a good Low-E coating (at least one layer, if not double Low-E), and argon gas fill (most come with it standard). And choosing a reputable installer like Karoly Windows paid off for us. Good luck with your project!

I'll chime in as well – I'm not far from Tampa (in Pasco County). I replaced my windows two years ago and did a lot of research on the technical side.
Low-E Coatings: In our climate, a good Low-E coating is a must because it reflects a lot of the sun’s heat. There are different types/brands, but generally you’ll see options like a single Low-E versus double or triple-layer coatings. More layers (like "LoĒ³" glass, which has three silver layers) will give you a lower Solar Heat Gain Coefficient (SHGC), meaning it blocks more of the solar heat. For Florida, you want a low SHGC. Many of the best windows for our area have SHGC around 0.25 or even lower. The trade-off can be a slight tint or reflective look to the glass, but in my experience it's barely noticeable. Definitely go for Low-E glass – it'll keep your home cooler and also block UV rays (protecting furniture from fading).

Gas Fills (Argon/Krypton): Most quality double-pane windows come with argon gas fill by default nowadays. Argon is an inert gas that slows heat transfer better than air, which improves the window’s insulating value (lowering the U-factor a bit). Krypton is another gas that insulates even better, but it's expensive and usually only used in triple-pane windows or special cases. For Florida, argon-filled double-pane is the sweet spot. Even if some argon leaks out over, say, 20+ years, the initial benefit is worth it (and good windows have warranties and low leakage rates). So yes, argon gas is a plus – just make sure whatever window you choose at least has argon.

Frame Materials: You'll mostly be looking at vinyl or aluminum frames here, though fiberglass and composite (like Andersen’s Fibrex) are also options.

Vinyl: Very common for replacements, and a good vinyl window has great insulation (vinyl doesn’t conduct heat much). High-quality vinyl is formulated for UV resistance – it can absolutely handle Florida sun without warping, as long as you stick to reputable brands. Vinyl is also resistant to corrosion (important in our humid, sometimes salty-air environment).

Aluminum: Strong and durable (and often used in older Florida homes and some current new construction), but aluminum conducts heat like crazy. Unless it has a thermal break (a piece of insulating material separating the inside and outside metal), an aluminum frame will let a lot of heat through. There are thermally broken aluminum windows (often used for some impact-rated designs) which are better than old aluminum but still not as insulating as vinyl. Aluminum can be a good choice if you need very large spans or thin frames, but expect more heat transfer than vinyl.

Fiberglass: More expensive, but very sturdy and also energy-efficient. Fiberglass doesn't expand/contract as much with heat and insulates well. Not as many companies offer fiberglass windows here, but there are a few (Marvin, etc.).

Composite (Fibrex, etc.): Also a solid option – kind of a mix of wood fibers and vinyl. Andersen’s Renewal line uses Fibrex and is known for durability and decent efficiency. They can be pricey though.

Impact Glass vs. Non-Impact: You mentioned considering impact-resistant glass. Impact windows are laminated and can withstand hurricanes. We opted not to get impact glass because we have hurricane shutters for all our windows. Non-impact double-panes were cheaper, and we just put up shutters when a storm comes. If you don't have shutters or hate putting them up, impact windows are very convenient (and some insurance companies give discounts for them). They also provide better soundproofing and security (harder to break). For us, the cost difference was about 30% more for impact glass, so we skipped it. But many window models can be ordered in either impact or non-impact versions (both with Low-E and argon). If budget allows and you want the peace of mind, impact is great – just not absolutely necessary if you already have protection.

Brand Recommendations: You've got quotes from Karoly and ProTech, which is good because local specialists know what's needed here. In terms of window brands:

PGT: Very popular in Florida (they make vinyl and aluminum impact windows, e.g., the PGT WinGuard and EnergyVue lines). Great for our climate; we ended up with PGT and have been happy.

Simonton: Another reliable brand (they have a StormBreaker Plus line for impact-rated windows).

Custom Window Systems (CWS): Florida-based manufacturer, good products for coastal conditions.

The big national brands (like Andersen, Pella) have offerings too (Andersen’s vinyl-clad or Fibrex windows, Pella has vinyl lines, etc.), but often the local Florida-focused brands give you more bang for your buck down here.

No matter the brand, check the window's NFRC ratings (they'll show U-factor and SHGC). For Florida, look for U-factor around 0.30 or below, and SHGC ideally 0.28 or below (lower = better for keeping heat out).

Lastly, installation is key: a great window can perform poorly if installed wrong. Sounds like you're looking at well-regarded companies (I’ve heard good things about both Karoly Windows and ProTech Windoors). Make sure whoever you go with pulls permits and installs to code (they should, in FL). Proper sealing (expanding foam, good caulk) around the windows during install will ensure you get the full benefit (no air leaks).

Hope this helps! Feel free to ask any specifics. I kind of nerded out on window research, so I'm happy to share. 😅

@jmartin52 We were in the same boat as you – old single-pane windows – and we also live in Tampa (Westchase area). We had our windows replaced about 6 months ago. I'll share our experience:
We ended up choosing double-pane vinyl windows with Low-E and argon (seems to be the standard combo these days). Specifically, we got Simonton brand windows. They are vinyl, non-impact, with Simonton's standard Low-E glass (Low-E2, I believe) and argon gas. We considered going for triple-pane or adding an extra tint, but decided it wasn't necessary for us.

After installation, the immediate difference in comfort was noticeable. Rooms that got harsh afternoon sun are much cooler now. Previously, even with the blinds closed, those rooms would heat up. With the new Low-E windows, the sunlight still comes in, but a lot less heat. We can actually keep the blinds open more often and enjoy the light without roasting.

Our energy savings have been decent. Comparing my July and August electricity usage to last year, we're seeing about a 10-15% reduction. It's hard to say exactly how much is from the windows alone (we also upgraded some insulation), but I’d attribute a good chunk of it to the windows because we really didn't change our A/C settings. The A/C does run less frequently to maintain the temperature.

Cost-wise, we paid around $800 per window (installed). That included a couple of large sliders which were about $1200 each and several smaller windows at ~$600 each. In total it was roughly $8,000 for 11 windows. We got quotes from three companies and ended up using a smaller local window contractor (not a big chain). They did a fine job.

One thing I’ll note: the Low-E coating on our windows has a very slight tint (a tiny bit greenish if you look from outside) but nothing you'd really notice unless you’re looking for it. From inside, the view is clear and the light looks normal – maybe slightly less harsh at peak sun, which is actually welcome. So don't worry too much about Low-E making your house dark; in our case it's still plenty bright, just not scorching.

Another benefit we love is the noise reduction. Suddenly, we don’t hear the lawn mowers and traffic nearly as much. We didn’t even think about that going in, but it's been a big plus.

Overall, very happy with the upgrade. If I could go back, the only thing I might have done differently is compare a couple more brands (just out of due diligence). But so far, Simonton has been great. No leaks, no condensation between panes, and they are easy to open and clean.

If you're on the fence, I'd say go for it. It sounds like you already have solid companies in mind. Just make sure to get at least a couple of quotes (which you did) and ask about warranties, lead times, etc. In Florida, it's a big investment but it definitely made our home more comfortable.

I have a question about the Low-E coatings. I've heard some people say that too much Low-E can make your windows look tinted or mirror-like. One of the window companies I talked to offers two options: a "standard Low-E" and an upgraded "solar Low-E" with extra coating layers. The rep said the solar Low-E blocks more heat (which sounds great for Florida), but I'm worried it might make the windows noticeably darker or reflective.
Has anyone noticed a big difference in appearance with the higher-performing Low-E glass? I do want the extra heat rejection for my west-facing windows, but not if it makes my house look like a mirror from the outside or makes the inside too dim. Any experiences with this?

@drummer573106 Great question. I opted for the "solar Low-E" (the one with the extra coatings) on my windows here in St. Pete, and I can share my experience.
In terms of appearance: from the outside, the windows with the higher-performance Low-E do have a slight reflective quality, but it's not like a mirror or anything extreme. In daylight, you might notice a mild greenish or grayish tint if you're really looking for it, and the glass is a bit more reflective than clear glass. However, it's subtle – my neighbors didn’t even realize we got "special" glass until I told them. At certain angles when the sun hits, you can see a faint reflection, but again, nothing like the shiny reflective windows you see on some commercial buildings.

From the inside, I honestly don't find it dim at all. We still get plenty of natural light. Colors might be ever so slightly cooler in tone because the Low-E blocks some of the infrared, but it's not something you'd notice unless comparing side by side. What we did notice is that the glare and harshness of the sunlight is reduced. It's more comfortable to sit by the window now.

Performance-wise: the solar Low-E made a big difference on the west side of our house. Those rooms are much cooler in late afternoon now compared to before. So for us, the tiny trade-off in appearance (which we barely perceive) is 100% worth the additional heat reduction.

If you are very particular about window clarity, you could ask the company if they have a sample piece of glass or a showroom where you can see the difference. I did that, and when I saw the "solar Low-E" glass in person, I was like, "oh, this is totally fine." It just looks like slightly tinted glass, similar to what cars have as a light factory tint (not the dark aftermarket tint).

So, my advice: go for the higher-performing Low-E, especially for west-facing windows. The cooling benefit outweighs any minor aesthetic difference in my opinion. And most guests or neighbors will never notice the subtle tint unless you point it out.

@jcoder32 Thank you, that’s exactly what I needed to know! 😊 I feel better about choosing the higher-performing Low-E now. I'll see if I can view a sample first, but it sounds like it won’t be an issue. Appreciate the detailed answer.

For those of you who got argon gas in your windows, did anyone mention how long the gas stays inside? I've read that argon can slowly leak out over many years. I wonder if after, say, 10-20 years, the windows lose that argon benefit (and does it make a huge difference anyway?).
Basically, should argon gas be a deciding factor? Or is it just a nice bonus that I shouldn't worry too much about?

@philosophy119 Good question. I'm not an expert, but I did ask the window installer about this when we got ours done. He said modern double-pane windows have a very slow leakage rate for argon – on the order of 1% per year or even less. That means after 20 years, you might still have ~80% of the argon in there (roughly).
Even if argon eventually dissipates, the impact on performance isn't huge. Argon might improve the window's insulation by maybe 10% compared to air. So if over decades it goes away, your window is still going to be functioning like a regular double-pane (just with air in between). The Low-E coating and the double-pane itself do most of the heavy lifting for energy efficiency; argon is like the cherry on top.

Most manufacturers seal the panes with materials that keep the gas in for a long time and often have warranties covering seal failures. A true seal failure (where you see fogging between panes) would cause argon to escape faster and moisture to get in, but then you'd likely get the window repaired/replaced under warranty.

In short: Argon gas is a nice benefit – it will give you slightly better efficiency initially and it doesn’t cost extra (most come with it standard). Over the life of the window, you might lose some, but it's not something to lose sleep over. I'd still choose a window that has argon fill, but I wouldn’t base my entire decision on minor differences in gas fill or worry that it'll all leak out quickly.

@andrew_mitchell Got it, thanks! Sounds like argon is a small plus but not a deal-breaker. I won't stress over it then.