Well, it’s deep into December and temperatures throughout the greater Tampa Bay area having lows in the high 50’s and highs of around 80 degrees on average, which is well above the low of 38 degrees Fahrenheit that we hit during the cold snap on November 11, 2025 (Source: NOAA). Do you have sufficient window insulation for your home?
With temperatures that can swing wildly from a frosty forty degrees to a hot upper 80’s, it can be difficult to keep your home comfortable while minimizing your energy consumption. Your AC might have to work hard to keep your home cool during the day when the sun’s beating down on your house with all of the heat and fire that gargantuan ball of fusion can muster.
At night, when the temperatures drop, the warmth can get sucked right out of your home, leaving you feeling frozen in your bedsheets and congested in the morning. Even as your heating system tries to keep your home warm, a lack of proper insulation can leave your house bleeding heat and let the cold creep in.
One of the best ways to keep your home comfortable whether it’s hot or cold outside is to improve the insulation throughout your home as much as possible. With better insulation, less heat transfers between your home and the outside world. This means you home stays warmer when it’s cold out, and cooler when it’s hot out.
A key point at which heat can enter or leave your home is the windows throughout the structure. Windows can be a weak point for your home’s insulation, especially older, single-paned clear glass windows that have poor insulation.
What can you do to improve window insulation and turn this gap in your home’s temperature control into a strong point?
How to Improve Window Insulation: Check & Replace Weatherstripping
Weatherstripping, or the material that is applied around a window (or door) to seal gaps, helps to reduce air infiltration and boost your window’s energy efficiency.
However, over time, weatherstripping can become cracked and damaged. This leads to gaps in the weatherstripping that lets air pass through more easily, compromising the seal around your window.
The time this takes varies depending on the type of weatherstripping you have. Weatherstripping is commonly made of materials like self-adhesive foam, vinyl, rubber, felt, or silicone, depending on the application. For example, garage doors often use rubber along the bottom since it’s slightly flexible and highly durable, able to take pressure without permanently deforming.
The U.S. Department of Energy strongly recommends “Vinyl, which is slightly more expensive” because it “holds up well and resists moisture.” In the Florida market, that second property of resisting moisture is of paramount importance, as homes near the coast are frequently subjected to moisture-rich air and heavy rainfalls.
If you’re having trouble keeping your home a comfortable temperature, check the weatherstripping around your window frame for signs of wear and tear. If it’s compromised, consider removing the old weatherstripping and replacing it with fresh material. This can be a useful thing to check at the start of the year.
To remove old weatherstripping, you’ll need to use a putty knife or pliers, clean the adhesive off with a soapy rag (or, if the weatherstripping was stapled on, use epoxy or wood putty to fill the holes), and let the window dry.
Once the old material is removed, then you can measure, cut, and apply the new weatherstripping to your window. That should help reduce the flow of air between your home and the outside, and it’s a fix you can do yourself!
How to Improve Window Insulation: Adding or Replacing Caulk
Another common gap in your window’s insulation is the area just around the frame of your window where it connects to the window opening. There may be tiny air gaps here that let heat move between your house and the outdoors. This is why any window installer worth their salt will carefully seal the area around your window with a layer of caulk.
However, when installations are done on the cheap, the installer might skimp on the caulking, leaving the gap between window and wall unprotected. Or, caulk might dry out and decay over time, creating cracks that let air leak in or out.
Whichever the case may be, putting caulk around your window frame can be a great, cost-effective, and relatively simple solution for improving window insulation.
To remove cracked old caulking, you can scrape the majority of it off with a putty knife, then go in with a soapy cloth and scrub the remainder off. Once dried, give it another round of cleaning with a dry cloth to remove any leftover chips or excess cleaner.
To apply new caulking, load your caulking gun, cut the tip of the caulk tube’s nozzle at a 45-degree angle, then hold the caulking gun at a 45-degree angle to the wall. The goal is to create a smooth, flat bead of caulk to the gap between the window and the wall. The steadier you can hold your hand and the pressure on the caulking gun as you move it up or down the line, the better.
When you’re done putting the caulk around the window, you can use a caulking tool or a damp finger to smooth out the bead further so it looks smoother and cleaner.
One optional step some homeowners might take to create a clean caulk line is to apply painter’s tape around the edge of the window frame. This lets you be a bit messier with the caulk and still get a clean line when you remove the tape right after you finish smoothing the caulk out.
How to Improve Window Insulation: Using Window Film Kits (AVOID)
Some stores sell DIY ‘window film kits’ that are advertised as being able to improve a home’s insulation by putting the equivalent of plastic wrap around a window to seal potential gaps.
There are, however, a few problems with these kits, even when you install them correctly.
While the kit may help fill an actual air gap, it doesn’t do much to improve the insulation of a window that doesn’t have a large air gap. This is because the layer of film on your window doesn’t do anything to improve the window’s Solar Heat Gain Coefficient (SHGC) or overall thermal transfer resistance.
The plastic wrap might restrict air flow if there’s a minor crack or gap in the glass in your window sash, but outside of that, you won’t see a major improvement in window insulation quality. If you have such cracks or gaps, you’ll probably be better served by replacing your windows rather than sticking a band-aid on them.
Window film kits really don’t do anything to fix the underlying issues that make a bad window less energy efficient. They’re a temporary “fix” that should be avoided.
How to Improve Window Insulation: Replacing Old Windows with New Ones
If you’ve done some basic DIY window insulation fixes and noticed that you’re still experiencing a lot of thermal bleed around your window openings, you might need to go a step beyond simply trying to “fix” your existing windows and replace them with more energy efficient windows.
This is especially useful if your windows are older and don’t meet modern energy efficiency standards. For example, say you’re in an older home with single-pane windows rather than the double-paned windows used in more modern construction.
Or, say that you have an aluminum-framed window that transfers heat easily. Even when metal windows are properly insulated, they tend to be less energy efficient because of how easily thermal energy transfers between them compared to more modern vinyl windows.
As noted by The Engineering Toolbox, Aluminum has a thermal conductivity of 237 W/m K (Watts per meter Kelvin). Meanwhile, polyvinylchloride (PVC) has a thermal conductivity of 0.19 W/m K.
In other words, for every unit of thermal energy that vinyl transfers, aluminum will transfer 1247.36 units of thermal energy.
Using windows that have at least two panes of glass with an air gap between them also significantly reduces heat transfer between your home and the outdoors by providing extra separation between the inside and outside of your home.
Another issue with some older windows or ones that weren’t installed properly is that the insulation around the window frame might be weak. Some installers who don’t specialize in window installation might underestimate the importance of window insulation when putting in new windows, skimping on the foam insulation around the installation site, creating a drafty space for air to pass through more easily.
Even the best windows won’t provide good insulation if the installation was handled poorly.
So, to fix your window insulation on a more permanent basis, replacing your windows entirely with brand new, expertly installed models that are up to the modern ENERGY STAR v7.0 standard is the best, most comprehensive solution.
For some homeowners, replacing old single-pane glass windows with ENERGY STAR-compliant windows can reduce their energy bills by 12% (Based on data from an ENERGY STAR survey).
Need Help Replacing Your Windows?
If you’re looking to maximize your window insulation and improve energy efficiency in your home, reach out to the experts at Karoly Windows & Doors!
Karoly Windows partners with top-rated window manufacturers in Florida to source high-quality windows that surpass ENERGY STAR standards. To maximize your energy savings, we also follow a specific process for installing new windows that ensures strong insulation around the window opening.
We can guarantee high-quality installation because we only ever use in-house labor for installing new windows. We never outsource to a third party subcontractor. Our installers are all in-house team members who we hold to do things the right way. The Karoly Way.
Get energy savings that last for decades by ordering new window installation from Karoly Windows & Doors!
