Successfully heating or cooling your entire living space lives in a tricky niche: at the corner of “ridiculously expensive” and “necessary for survival”. Hopefully, you already have a major heating or cooling unit at home, but with older buildings, you may not be getting the most bang for your buck. What’s a person living on a budget to do?
To get to the bottom of this, I decided to try out a few relatively cheap, easy-to-use products that I found online. Each product promises to make your heating or cooling system more effective by reducing, blocking, or removing areas where the hot or cold air can escape. But do any of them work?
I put them to the test here at Reviewed.com HQ in Cambridge, MA, where outside temperatures can range from sweltering to bitterly cold. Here's what I discovered.
Duck Brand Indoor 10-Window Shrink Film Insulator Kit
This product is basically cling film secured with tape that goes over your external or internal windows. The kit is ideal for single pane or cracked windows, as it basically acts as a second layer of glass. Outside air has a difficult time getting through the plastic film, which means your warm or cool indoor air can’t get out either.
I used this in my office, where one of my windows has a big crack in it. Getting the tape to stay put was a nightmare, and the cling film did its best to cling anything and everything—including the last vestiges of my sanity—but things went much more smoothly once I had everything in place.
Admittedly, I did burn a hole through one of my cling films while using a hairdryer to smooth it into place (whoops!) but in the end, the cling film firmed up nicely. Another bonus of this product is that you can’t tell it’s been done at all; both the tape and the cling film are difficult to see, even if you know they’re there.
Pro Tip: Before you start, take note of the area around the window you want to cover. Just like regular tape, this product will not do well if you try to stick it to plain drywall, unpainted or unstained wood, or plaster.
How to install it:
- Clear out an area near the window you want to cover. This will be your workspace.
- The film is going to be stretched across the outer edges of the window, on top of the window frame. Measure the width and the height of the window, plus a 2” border that sits on the window frame. Give yourself some extra room, if possible.
- Measure it again, just to be safe.
- Roll out the double-sided sticky tape. Cut four pieces—two that match the height of the window plus your 2" border, and two that match the width of the window plus the 2" border.
- Unpeel the sticky tape from its backing and apply it to the window frame. Gently press the tape down with something that is not your finger, but will probably not stick to the tape. I used the flat head of a screwdriver.
- Unroll the cling film slowly. You may need to weigh it down with something heavy to keep it flat.
- Cut a piece of the cling film to the size of the window as you measured it earlier, plus that 2” buffer.
- Press one corner of the cling film to a corner of the sticky tape, leaving a bit of excess on the outer edge if you can. Here's where you'll be glad you cleared a workspace: As I learned, the cling film lives up to its name, clinging to anything that happens to lie between you and the window (toys, curtains, family pets) or even to itself. Move slowly and you'll be fine!
- Gently but firmly press the rest of the cling film onto the tape around the window, making sure that the film is not sagging at all. The film doesn’t have to be very tight, but there should be very little cling film slack in the middle of the window after you’ve pressed it across the entire window. You may notice slight crinkles or lines in the cling film; don’t worry about that for now.
- Take up your hair dryer or heat gun. Turn it on at a low setting, hold it about 8” from the surface of the cling film, and wave it slightly from side to side. DO NOT GET CLOSER THAN 6” FROM THE WINDOW. You will burn a hole right through the cling film. When done correctly, the cling film starts to contract and smooth away all of those wrinkles. It can even help with folded, wrinkly film that is stuck on the tape. Just point, shoot, and defeat those cling film folds!
- Trim any extra cling film material that goes past the tape edges. Success!
By sealing your windows with this cling film, you should definitely notice that you are retaining more conditioned air, and losing less to the outside world. That's what makes it worth the effort.
Great Stuff Pro Foam Insulating Kit
Spray foam insulation is a great way to seal up cracks and holes in your home, whether it’s water or air that’s trying to escape or intrude. The Great Stuff Pro spray foam sealant is made for small gaps and cracks in vinyl, metal, and wood surfaces. In my case, I applied it to the gap between metal and brick surfaces, and it worked beautifully.
I was looking to seal up the gaps between a metal loading dock door and the brick wall of our building. It felt like a lot of air was moving through these gaps, so I was eager to seal them up with foam insulation. If the walls around your windows or doors are cracked, this is a fantastic way to prevent cold/hot air from coming into the house because it can be used on both interior and exterior surfaces.
I used the spray foam gun and the cleaner, which made the experience much easier. Bonus: The spray foam gun made me feel a bit like James Bond, if James Bond was into DIY home insulation projects.
Pro Tip: the spray foam creates a strong, permanent bond. If the surfaces that are cracked are not similarly strong (i.e. drywall), then the spray foam probably won’t do you much good. In the case of drywall, think about patching the drywall first.
Here’s what to do:
- Wipe down the surfaces you intend to seal with a damp cloth. The foam will stick better to the surface if it is dust- and dirt-free.
- Unscrew the top of the foam sealant, and slowly screw the gun on, upside-down, to the top of the foam sealant.
- Hold off on spraying your wall for a moment to first pull the trigger of the spray foam gun into the garbage, keeping the gun upright. As you’re doing this, adjust the black knob on the back to change the “bead size” (or how wide the jet of spray foam is).
- Once you’ve picked a satisfactory bead size, aim the gun at the gap(s) in the wall. With the foam insulation, a little bit goes a long way. The foam insulation expands A LOT, so before you unload like you have an automatic weapon and you’re being attacked by zombies, try a few test spots first. If you want even finer control of where the jet of spray foam goes, try using one of the plastic tips that fits over the gun nozzle. Note: Do your best not to get the foam on your hands. It feels weird, and can be tough to clean off.
- Spray foam in the rest of the area that you want to seal.
- Once you’re done spray foaming, set the gun down upside-down, so that the can of foam is right-side-up. Carefully unscrew the gun from the foam can and recap the can with its black plastic cover.
- Open the foam gun cleaning solution, and screw the gun upside-down on top of the cleaning solution can.
- Spray the gun with the cleaning solution into the garbage. This will clear out any leftover foam that remained in the barrel of the gun and will make it much easier to start foam spraying again next time. Spray until all the leftover foam has stopped coming out of the gun.
- Turn the cleaning solution right side up, unscrew the gun from it, and recap it.
- Let the spray foam insulation dry overnight.
My spray foam job came out rather blobby, so I smoothed it down with sand paper, then painted it to match the color of the walls. It's worth noting that the foam is bright orange, so you may want to get a paintbrush ready if you don't want it to stand out.
While the loading dock door I insulated lets out some air because it's, well, a door, sealing the perimeter of the door has noticeably improved the room’s ability to maintain a consistent temperature.
BDF Window Film Privacy and Sun Control
As advertised, this window film works both as a privacy screen (so that your nosy neighbors can’t see you rocking out to Britney Spears) and as a sun blocker for your windows. The film basically acts as a tinted one-way mirror: you can see out, but no one can see in—not even the sun. Light is absorbed by the dark tint of this film, which drastically reduces the amount of heat coming in from the outside. This can save you considerable money on your air conditioning bills.
This summer, I decided to install this window film on the windows in our lab, which were letting in too much heat. The whole process took a week, and I'll be honest: there was a steep learning curve.
Pro Tip: Have a rough estimate of the size of your windows beforehand, so that you don’t accidentally buy film that's too narrow to cover the width or height of your window.
Here’s how to do it:
- Before installation, clean the windows. If there is any dirt or grime stuck to the window, remove it.
- For a work area, clear out and use the area near the window to which you will be applying the film. Sweep the floor of your work area.
- Measure the height and width of the glass in the window.
- Measure the height and width of the glass in the window again, just to be safe.
- Mix up a cleaning solution in a spray bottle. I used a combination of water and dish detergent.
- Gently roll out the film. The side of the film that is facing the inside of the roll is the part that will be sticking to the window. Cut the film to the dimensions of the window using the included box cutter, leaving a buffer of an inch or two around the edge. Once it’s cut, move the film to a location closer to the window.
- Stick a piece of tape to the top side of the film. This is the side that will be removed, revealing the sticky back to the film.
- Spray the window with cleaning solution. You'll know you've sprayed enough when the solution is just starting to run down the window glass. Take care not to apply too much cleaning solution.
- With the help of a friend (or ten!), VERY SLOWLY peel back the adhesive backing of the film. Holding the film, stand as far as possible away from anything that the film could stick to (including your ten friends).
- VERY SLOWLY, carry the film toward the window, sticky side facing away from you. This has to be done carefully because the film can easily twist, stick to itself, and get all crinkly.
- While the window surface is still wet, press the sticky side of the film onto a corner of the window, leaving that 1”-2” buffer free. Gently press the film down on the entire window. If you make any mistakes, pull the film up again right away, re-spray the water soap/solution on the window, and try again. Make sure the edges are as smooth as possible.
- Use the flattening tool included with the product to press out all of the air bubbles trapped beneath the film. If you're having trouble, spray some cleaning solution on the outside of the film so that your flattening tool glides more easily.
- Let the film sit for a few minutes, then come back and check for more bumps and air bubbles. Use the flattening tool to remove them.
- Let the film sit overnight. Trim the buffer edges of the film with the box cutter.
As you may have guessed from the how-to list, I encountered many problems installing this film. A number of times, as I peeled away the adhesive backing, the film stuck to itself (or me), and got all crinkly and ruined. It was tough to line the film up perfectly with the tall lab windows. At one point, I made the mistake of spraying too much cleaning solution on a window, which created a massive air pocket in the film, preventing it from adhering to the glass. I actually had to tear the entire piece of film off and try again.
All of the installation angst aside, I really like how the film turned out. It definitely keeps a lot of the direct sun from entering our lab, and makes it easier to maintain cooler temperatures in the summer. Additionally, once the film is smooth, you can’t even really tell it’s there. I realize that this probably won’t be a go-to product for decorative or upper-floor windows, but it’s great for windows that don’t face the street or aren't vital to the resale value of your home.
General Electric Caulk + Newborn Caulk Gun
Caulking your old windows and doors is a great, cheap way to save on heating and cooling. Caulk is a gooey, yet semi-rigid material that is meant to seal cracks in the wall. In some ways it's pretty similar to spray foam, except it's generally used on a much smaller scale.
There's a window in the lab where the molding had rotted away, causing the glass pane to rattle around in the frame. Using caulk that I color-matched to the window frame, I filled the gap in the window frame, stopped the glass from rattling, and preserved just a little bit more of that precious cool interior air.
Caulk that doesn’t come in a rigid tube meant for a caulk gun is typically used for spot treatments (like filling drill holes in drywall), while filling a window frame is a job for a caulk gun.
Here’s how to do it:
- Select a caulk that is appropriate both in purpose (interior/exterior) and color (white/black/clear) for the window or door frame you're planning to seal up.
- Using a damp cloth, wipe the area around the glass and the frame. The caulk will work better if it's not trying to adhere to dust or dirt.
- Remove the cap from the top of the caulk tube.
- Holding the caulk gun, pull the metal back end all the way out. Direct the pointy part of the caulk tube into the hole marked “spout cutter”, and then pull the trigger on the caulk gun. The spout cutter will cut off the tip of the caulk tube.
- Unfold the long, thin metal rod that lives beneath the bottom of the barrel of the caulk gun. Stick it into the open hole of the caulk tube. This will puncture the protective layer of plastic inside the tube that stops the caulk from running all over the place. You may have to puncture that barrier a few times before the caulk flows freely. Fold the rod back under the caulk gun to avoid poking yourself in the future.
- Place the caulk tube into the caulk gun. Push the metal rod at the back of the gun inwards so that the flat back piece is resting against the back of the caulk tube.
- Pull the trigger of the caulk gun a few times to ratchet that rod further into the caulk tube. Stand close to the window so that when caulk starts coming out, you can instantly start applying it to the window.
- Fill the window frame with the caulk. Once you’ve completed an edge, smooth it down with your finger, and scoop up the extra with a paper towel or a piece of cardboard.
- When you’re finished caulking the window/doorframe, pull the metal rod at the back of the caulk gun all the way out, remove the caulk tube from the gun, and cap the caulk tube.
- Let the caulk sit overnight.
- Carefully, using a box cutter, trim away any excess caulk. If some extra caulk is stuck on the window itself, use a razor blade to scrape it away.
Out of all of the projects I’ve listed so far, caulking a window/door frame is by far the cheapest and easiest. If you can feel gusts of air coming from around the edges of your windows, caulking it thoroughly may be the best solution.
The one window I caulked was also a window to which I applied tinted film, so it’s tough to say which product was responsible for the improved heating and cooling of the room. That said, ensuring that your windows are better sealed—whether it’s with caulk or cling film—will doubtlessly help you feel warmer in winter and cooler in the summer.
Bonus: Install a room divider
In our labs, we have to cool a massive space with a very old air conditioning unit. Replacing the A/C unit would cost tens of thousands of dollars, so instead, I installed a strip curtain.
Strip curtains are often found in open-air refrigerators where something has to be kept cool, yet remain easily accessible. The strips of plastic, while easy to walk through, form a barrier that makes it much more difficult for hot air to enter or for cold air to escape.
While I wouldn’t advise hanging a strip curtain in your home, you can do something similar: create a room divider to reduce the amount of air your A/C has to cool or your heater has to heat. This will be difficult in open concept living spaces, but in older houses with many rooms, this is more doable.
This project could be as elaborate as hanging sound- and light-dampening curtains across the door to the office, or as simple as hanging a shower curtain across the entrance to the dining room.
Out of all the efficiency-increasing solutions I’ve done, hanging the strip curtain was far and away the most effective. Even people in the office who are unaware of the purpose of the strip curtain comment that it is vastly cooler on one side than it is on the other.
For everyone dreading the freezing times of the coming winter, there is hope. If getting a brand new heating unit is out of the question, try these cheaper, smaller fixes. While they take time to prepare and install, they will help to keep you warm and save you money.