Compression Seals for Windows

We use compression seals for windows because it’s simply the best way to seal against drafts and noise. The silicone in our compression system stands up to heat and sun while nearly disappearing into the window frame. It was designed with a refrigerator magnetic seal in mind, but improved and simplified to make it stronger and easier to remove and reinstall.

close up of compression seal for windows created by Indow window inserts

How Indow Inserts Seal Windows

We use acrylic panels surrounded by silicone tubing to create our one of a kind window inserts. We use acrylic because it’s better for thermal and sound control than glass. We use silicone because it’s the best quality: long-lasting and resilient so it won’t lose its spring force over time.

Just like the Ove Glove, which uses silicone to protect your hands in the oven and keep the glove from being altered by heat, your window insert frames will stand up to the elements. They’ll be exposed to sun, heat, and UV rays for years, but will never change shape or lose their compression force.

“Silicone is almost impervious to UV radiation which exists in abundance in window frames, it’s highly resistant so it’s not going to lose its spring force over time. There’s something in engineering called compression set which is how much something loses its spring force when it’s squeezed for a long time and silicone has the very best compression set properties and durability properties.” -Sam Pardue, Indow Founder

Indow CEO installing first window insert with compression seal

Founder and CEO Sam Pardue installing one of the first Indow inserts sold, in the first year of the company’s history

Evolution of the Compression Seal for Windows

close up of tubing used for compression seal for windows

We originally had a magnet inside our tubing to seal windows. We wanted to improve the magnetic attachment system by accommodating for the acrylic panel’s thermal expansion and contraction while cleaning up the appearance by removing the need for a big metal frame on the window.

The plan was to make the frame of the insert act like a refrigerator magnetic seal. If you look at a refrigerator door, it’s a magnet surrounded by a compression seal. So, we were going to combine a magnet and compression tubing, just like a refrigerator magnetic seal.

woman installing compression seal window insert

VP of Marketing, Kristina Damschen Spina, installing the insert in the kitchen where the product was invented.

The initial prototype failed. It also didn’t look great. We removed the magnet and just used the spring force of the compression seal and worked! It looked so pristine in the window frame you could hardly see it. We accomplished everything we wanted: a near airtight seal for windows, a near perfect appearance, and no harm done to the window frame.

close up of Indow window compression tubing system

We didn’t stop there. We continued to innovate on the perfect way to seal windows, adding more compressive range and increasing the amount of spring force. We even added space in the tubing for a metal spine for added stability on large inserts. We’re constantly optimizing different aspects of our window insert from compression seals for windows to customer usability.

Seal Windows in Any Environment

We continuously improve our compression seal for windows to create the best draft- and noise-blocking window inserts possible. Together acrylic and silicone forge a perfect sound and climate control combination. They are both resilient, standing up to sun exposure without losing their effectiveness.

No matter what window issue you have, there is a window insert that can help. Take a look at all of our products to see what works for your situation.

Customer Reviews


4.49 Average 1477 Reviews logo

Matthew L

Indow inserts were easy to measure, order and install. They've provided great insulation for old single-pane and stained glass windows in an antique home. We can significantly feel how much better the home holds heat.

Posted 2 days ago

Ellis W

I ordered two Indow inserts for my home. They are doing a great job, entirely happy with them and the ordering process.

Posted 1 week ago

Elizabeth W

I can't say enough good things about this product and company. Our house is 101 years old and the sidelites next to our front door are single pane ancient wavy glass which means when it gets very cold (Chicago temps) we can have an inch of frost covering the INSIDE of our windows. I was desperately searching for a solution so our front vestibule was not so cold and a friend recommended Indow. The process could not have been simpler and the temperature difference it has made is off the charts.

Posted 2 weeks ago

Austin T

I have several historic single pane gridwork mullion windows. They're beautiful but have almost no thermal protection. Indows proved to be the perfect solution to preserve these windows while getting the thermal comfort we need. They were easy to install and work perfectly!

Posted 3 weeks ago

Kathryn M

Amazingly easy to install even the safety chain holders. I. Noticed an immediate sound level difference and the room atmosphere became more solid feeling and pleasant. They also gave an insulating feature to the window drafts are non existent! The house is 50ft off a State highway that is heavily traveled in warmer months I'm confident the indows will handle it. I'm very pleased!

Posted 1 month ago


We ordered the acoustic inserts to help with road noise, and we've been sleeping so much better with them!

Posted 1 month ago

Sienna K

We used the windows inserts in our skylight. They are great! They the horrible drafts and noise out and were cost efficient. My only comment would be to provide better measurement and installation instructions for skylights specifically. It took us a lot of guessing and research to measure and install because skylight directions were not provided and the windows install guide doesn't always apply to skylights. Other than that though great product and I would buy again!

Posted 1 month ago

ted t

Our home was built in the late 1800s and we have spent a lot of money over the last 20+years restoring it.We did not want to replace the windows with modern windows because of the cost and originality. But the single pane windows come with a price also. the main reason we purchased the Indow window inserts is because of the condensation on the inside of the windows.We would literally have a take a towel and wipe them down every morning in the winter. There would be a puddle on the sill,and wood and water dont get along to well. SO we looked into the best solution to our problem and found Indow. Was reluctant to spend that much money but am super glad we did!! They have been installed now for over two months and our condensation problem has been virtually eliminated.!!! AND our furnace does not run as much as it did before. Over all it was money well spent!! The process was a little scary at first but they have a simple formula. And our contact person,Reed was awesome. Answered any questions i had and was always available.

Posted 1 month ago


Used to block interior side of a garden window in the the kitchen. Without insert, cold air literally poured into the kitchen making a winter jacket almost mandatory when preparing meals or washing dishes

Posted 1 month ago

Rob S

Highly recommend! The team (Brian) took time to help me figure out the best solution. They were made and delivered faster than expected. It was very rewarding to install them because I could feel the cold air get squeezed out as they went flush against the single pane of glass. Solid quality and great fit.

Posted 1 month ago

Alexa L

My inserts fit beautifully into my 125 year old windows - many of which were 5 feet tall. Easy to unwrap and install. Great product and even better service! I liked the process of measuring the windows with a laser measuring tool which was easy to use and precise. The product came in good condition after shipping across country and was well marked. The customer support was excellent.

Posted 1 month ago

Sarah D

Received our Indow Windows and can tell they are blocking a lot of the noise we could hear. Right now the weather is mild, but hoping to notice a big difference when the summer heats up. Our house is in a historic district and we cannot change our windows. They are very drafty and thin glass. We only ordered two, but we are in the process of ordering for four more. Love that we don’t need to drill holes or anything and they just pop right in.

Posted 1 month ago

Allan F

Every thing arrived in perfect condition, thanks to the very secure packaging. Windows fit as expected, although quite tight. After installation we noticed that the cold drafts were gone and the room felt a lot warmer. We are very satisfied with the product and the result.

Posted 1 month ago

Adriana W

Great customer service! Super satisfied with our windows.

Posted 1 month ago

Thomas M

Indow service and product is good. Reduced outside noise considerably.

Posted 2 months ago