--- title: What Does A Blower Door Test Do? description: What even is a blower door test? Discover the purpose of blower door testing and how it works in a home or building. image: https://scsfoam.com/hubfs/Article%20Title%20Images/What%20Does%20A%20Blower%20Door%20Test%20Do.jpg --- [Skip to main content](https://scsfoam.com/blog/what-does-a-blower-door-test-do#maincontent) [(717) 895-3498](tel:7178953498) [![South Central Services Insulation](https://scsfoam.com/hs-fs/hubfs/branding/Website%20Logo%20Classic.png?width=900&height=300&name=Website%20Logo%20Classic.png) ![South Central Services Insulation](https://scsfoam.com/hs-fs/hubfs/branding/Website%20Logo%20White.png?width=900&height=300&name=Website%20Logo%20White.png)](https://scsfoam.com/) [Our Service Areas](https://scsfoam.com/our-services-areas) Pricing - [Our Rates](https://scsfoam.com/our-rates) - [Calculators](https://scsfoam.com/pricing-calculators) - [Financing](https://scsfoam.com/financing-options/) - [Rebates](https://scsfoam.com/rebates) [Our Team](https://scsfoam.com/our-team) Services - Residential Insulation - [Attic Insulation](https://scsfoam.com/attic-insulation) - [Basement Insulation](https://scsfoam.com/basement-insulation) - [Crawl Space Repair](https://scsfoam.com/crawl-space-encapsulation) - [Commercial Spray Foam](https://scsfoam.com/commercial-spray-foam/) - [New Construction Insulation](https://scsfoam.com/new-home-construction-insulation/) - [Pole Building Insulation](https://scsfoam.com/pole-building-insulation) - [Air-Sealing](https://scsfoam.com/air-sealing) - [Blower Door Tests](https://scsfoam.com/blower-door-tests) [Our Products](https://scsfoam.com/our-products) Learning Center - [Learning Center](https://scsfoam.com/learning-center) - [Downloadable Resources](https://scsfoam.com/downloadable-resources) - [FAQ](https://scsfoam.com/faq/) Open Search [Get A Quote](https://scsfoam.com/contact/) Search for topics or resources Enter your search below and hit enter or click the search icon. Search for topics or resources Close Search [Our Service Areas](https://scsfoam.com/our-services-areas) Pricing Pricing [Our Rates](https://scsfoam.com/our-rates) [Calculators](https://scsfoam.com/pricing-calculators) [Financing](https://scsfoam.com/financing-options/) [Rebates](https://scsfoam.com/rebates) [Our Team](https://scsfoam.com/our-team) Services Services Residential Insulation Residential Insulation [Attic Insulation](https://scsfoam.com/attic-insulation) [Basement Insulation](https://scsfoam.com/basement-insulation) [Crawl Space Repair](https://scsfoam.com/crawl-space-encapsulation) [Commercial Spray Foam](https://scsfoam.com/commercial-spray-foam/) [New Construction Insulation](https://scsfoam.com/new-home-construction-insulation/) [Pole Building Insulation](https://scsfoam.com/pole-building-insulation) [Air-Sealing](https://scsfoam.com/air-sealing) [Blower Door Tests](https://scsfoam.com/blower-door-tests) [Our Products](https://scsfoam.com/our-products) Learning Center Learning Center [Learning Center](https://scsfoam.com/learning-center) [Downloadable Resources](https://scsfoam.com/downloadable-resources) [FAQ](https://scsfoam.com/faq/) [(717) 895-3498](tel:7178953498) [Get A Quote](https://scsfoam.com/contact/) [«  View All Posts](https://scsfoam.com/blog) # What Does A Blower Door Test Do? December 2nd, 2024 2 min read By [Kilian Agha](https://scsfoam.com/blog/author/kilian-agha) ![](https://scsfoam.com/hubfs/Article%20Title%20Images/What%20Does%20A%20Blower%20Door%20Test%20Do.jpg) You might need a blower door test for your home. But what’s the goal of blower door testing? What does one of these tests do? South Central Services offers certified blower door testing. We service areas like Harpers Ferry, WV, and Hagerstown, MD. By the end of this article, you will understand: - What blower door tests are used to quantify - What blower door test results mean - How blower door tests can help you - What happens during a blower door test > Don't have time to read right now? Check out [everything you need to know at a glance](https://scsfoam.com/hubfs/At%20A%20Glance/What%20Does%20A%20Blower%20Door%20Test%20Do.pdf). ## Blower Door Tests Quantify Air Leakage In A Building. Blower door testing is a precise method of calculating air leakage. These tests quantify results as the number of air changes per hour (ACH). Essentially, how much air is exchanged between the inside and outside of the building within an hour? If air is not exchanging mechanically (through your HVAC system) or naturally (through a door or window), then there is an air leak. Blower door tests can tell you how leaky a building is. ## Blower Door Tests Determine If Buildings Are Energy Efficient. The reason why blower door testing exists is because air leaks waste energy. > Traditionally, leaks were considered a good part of construction, because they let the house "breathe" a little. In more recent years, the role of air leakage in energy waste has been discovered. Since energy is an expensive and precious resource, it makes sense not to needlessly waste it. The [International Energy Conservation Code (IECC)](https://www.iccsafe.org/products-and-services/codes-standards/energy/) has made blower door testing a requirement for new construction buildings. This requirement will help ensure that new buildings do not allow air to leak excessively between the inside and outside of the building. ## Blower Door Tests Show Where Air Leakage Is Happening. Air leakage happens within the [thermal envelope](https://scsfoam.com/blog/spray-foam-insulation-glossary#building-envelope-definition) of a building. The thermal envelope usually includes: - Attic - Basement - Crawl space - Exterior walls Any gaps or cracks in these areas, which form the barrier between the building and the outside world, can result in air leakage. If a building is leaky, you can assume there are air leaks in some of these four areas. However, a blower door test allows you to be more specific about what area of a home is compromised. > By not assuming the problem, you can directly address and resolve air leakage. Once air leakage is fixed, [energy costs lower significantly](https://scsfoam.com/blog/does-spray-foam-insulation-save-money). ## Blower Door Tests Pressurize Or Depressurize A Building. So, how exactly does a blower door test work? A certified technician installs a blower door fan in the exterior door of a building. When the fan is turned on, it either blows air inside or pulls air outside. The blower door test will work whether the building is pressurized or depressurized. ![A technician from South Central Services completing a blower door test on a new construction home.](https://scsfoam.com/hs-fs/hubfs/Article%20Graphics/Performing%20A%20Blower%20Door%20Test.jpg?width=533&height=400&name=Performing%20A%20Blower%20Door%20Test.jpg) The technician then uses specialized equipment to carefully measure any air that exchanges. You can visualize this like an open window. If a fan pulls out all of the air in the room, an open window will let new air back inside. The blower door test finds any cracks or gaps that let air exchange. When the test is complete, the technician can provide an official report quantifying the ACH. ## The Bottom Line About What Blower Door Testing Is Blower door testing has become a requirement for new construction homes via the IECC. A certified technician must perform a blower door test. These tests quantify air exchanges in the building. Blower door testing aims to identify and resolve any problematic air leaks that will cause excessive energy waste over the structure's lifetime. Now that you understand what a blower door test is, your next step is to: - [Discover how much blower door tests cost](https://scsfoam.com/blog/blower-door-test-cost) - [Learn how blower door tests are performed](https://scsfoam.com/blog/how-blower-door-tests-are-performed) - [Request a blower door test from South Central Services](https://scsfoam.com/blower-door-tests#contact) [![SCHEDULE MY TEST](https://no-cache.hubspot.com/cta/default/39735758/interactive-183818988804.png)](https://scsfoam.com/hs/cta/wi/redirect?encryptedPayload=AVxigLJI8u1GlXMRkF5b0qPrQgOTXZyKQIg7neS2urTXd7nhu%2FAU6hSIil5JmeaXYaQTOy3G1oz36JcT6bcjx6CGIlZ%2F77NNPZTdUIU9uaYdU%2FffuuWPrsQf67zmJ3U3vUxG6padPTFZwQwC9SyOp%2BsV9z%2BQpZXDeMf8fm%2FTKVWUD%2Bid0xALvnkDq%2B45%2FZZeKnIhwA%3D%3D&webInteractiveContentId=183818988804&portalId=39735758) *Disclaimer: While we strive to publish information accurate to building science, local building codes and standards supersede our recommendations.* [Kilian Agha](https://scsfoam.com/blog/author/kilian-agha) Kilian has co-owned and operated South Central Services for 8 years. He is passionate about community involvement. In his spare time, he enjoys being with his family, playing ice hockey, and going fishing with friends. Topics: [Fundamentals](https://scsfoam.com/blog/topic/fundamentals) [ACH Testing](https://scsfoam.com/blog/topic/ach-testing) Don't forget to share this post: ## Related Articles ### [16 Terms To Know When Insulating Your Basement June 13th, 2025|4 min read](https://scsfoam.com/blog/terms-to-know-when-insulating-a-basement) ### [25 Terms To Know When Insulating A New Home May 21st, 2025|6 min read](https://scsfoam.com/blog/terms-to-know-when-insulating-a-new-home) ### [Why Does Spray Foam Turn Yellow Over Time? January 15th, 2025|2 min read](https://scsfoam.com/blog/why-does-spray-foam-insulation-turn-yellow-over-time) ### [Why Is Spray Foam A Good Insulator? December 11th, 2024|4 min read](https://scsfoam.com/blog/why-spray-foam-is-a-good-insulator) ### [Why Does Spray Foam Change Color? November 4th, 2024|3 min read](https://scsfoam.com/blog/why-spray-foam-insulation-changes-color) ### [Does Spray Foam Insulation Lose Its R-Value? September 11th, 2024|4 min read](https://scsfoam.com/blog/does-spray-foam-lose-r-value) ### [What To Expect From An Insulation Upgrade June 12th, 2024|5 min read](https://scsfoam.com/blog/what-to-expect-from-an-insulation-upgrade) ### [Can You Spray Foam Behind Drywall? May 15th, 2024|5 min read](https://scsfoam.com/blog/can-you-spray-foam-behind-drywall) ### [6 Problems With Spray Foam Insulation Explained April 8th, 2024|5 min read](https://scsfoam.com/blog/problems-with-spray-foam-insulation-explained) ### [Can Open Cell Spray Foam Create A Vapor Barrier? March 27th, 2024|3 min read](https://scsfoam.com/blog/can-open-cell-create-a-vapor-barrier) ### [Is Spray Foam Insulation Safe To Breathe? March 4th, 2024|3 min read](https://scsfoam.com/blog/is-spray-foam-insulation-safe-to-breathe) ### [Can You Put Spray Foam In Existing Walls? January 26th, 2024|4 min read](https://scsfoam.com/blog/can-you-put-spray-foam-in-existing-walls) ### [What Is Flash And Batt Insulation? January 3rd, 2024|6 min read](https://scsfoam.com/blog/what-is-flash-and-batt-insulation) ### [What Is Spray Foam Insulation Made Of? December 20th, 2023|4 min read](https://scsfoam.com/blog/what-spray-foam-insulation-is-made-of) ### [What Is Crawl Space Encapsulation? December 15th, 2023|7 min read](https://scsfoam.com/blog/what-is-crawl-space-encapsulation) ### [Is Installing Insulation Dangerous? December 13th, 2023|3 min read](https://scsfoam.com/blog/is-installing-insulation-dangerous) ### [Which Type Of Spray Foam Insulation Is Best? December 4th, 2023|7 min read](https://scsfoam.com/blog/which-spray-foam-insulation-is-best) ### [What Does R-Value Mean In Insulation? November 17th, 2023|4 min read](https://scsfoam.com/blog/what-insulation-r-value-means) ### [What Does Spray Foam Stick To? Spray Foam Insulation Application Guide October 18th, 2023|5 min read](https://scsfoam.com/blog/spray-foam-insulation-application-guide) ### [5 Reasons Why Your Energy Bill Is So High (And Fixes You Can Try) October 4th, 2023|3 min read](https://scsfoam.com/blog/why-is-my-energy-bill-so-high) ### [Why Does Spray Foam Insulation Off-Gas? September 18th, 2023|2 min read](https://scsfoam.com/blog/why-does-spray-foam-insulation-off-gas) ### [How To Save Energy In Your Home September 6th, 2023|6 min read](https://scsfoam.com/blog/how-to-save-energy-home) ### [How Spray Foam Insulation Is Made August 28th, 2023|5 min read](https://scsfoam.com/blog/how-spray-foam-insulation-is-made) ### [What Is Spray Foam Insulation? August 11th, 2023|6 min read](https://scsfoam.com/blog/what-is-spray-foam-insulation) Location 1574 Buchanan Trail East, Greencastle, PA 17225 Phone: [(717) 895-3498](tel:7178953498) Connect With Us - [Facebook](https://www.facebook.com/p/South-Central-Services-Insulation-100057064885687/) - [Instagram](https://www.instagram.com/scsfoam/) - [YouTube](https://www.youtube.com/@scsfoam) - [info@scsfoam.com](mailto:info@scsfoam.com) Services - [Attic Insulation](https://scsfoam.com/attic-insulation) - [Basement Insulation](https://scsfoam.com/basement-insulation) - [Crawl Space Repair](https://scsfoam.com/crawl-space-encapsulation) - [Commercial Spray Foam](https://scsfoam.com/commercial-spray-foam/) - [New Home Insulation](https://scsfoam.com/new-home-construction-insulation/) - [Pole Building Insulation](https://scsfoam.com/pole-building-insulation) - [Air-Sealing](https://scsfoam.com/air-sealing) - [Blower Door Tests](https://scsfoam.com/blower-door-tests) Pricing Information - [Our Rates](https://scsfoam.com/our-rates) - [Calculators](https://scsfoam.com/pricing-calculators) - [Financing Options](https://scsfoam.com/financing-options/) - [Rebate Information](https://scsfoam.com/rebates) - [Pricing Articles](https://scsfoam.com/blog/tag/product-pricing) Proud Member of Cumberland Valley Business Alliance     Company - [Our Service Areas](https://scsfoam.com/our-services-areas) - [Our Products](https://scsfoam.com/our-products) - [Our Team](https://scsfoam.com/our-team) - [Contact Us](https://scsfoam.com/contact/) - [Join Our Team](https://scsfoam.com/our-team#hiring) - [Privacy Policy](https://scsfoam.com/privacy-policy) Learn More - [FAQ](https://scsfoam.com/faq/) - [Learning Center](https://scsfoam.com/learning-center) - [Downloadable Resources](https://scsfoam.com/downloadable-resources) © 2026 South Central Services All Rights Reserved. ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Kilian Agha", "url" : "https://scsfoam.com/blog/author/kilian-agha" }, "dateModified" : "2025-03-31T17:16:40.693Z", "datePublished" : "2024-12-02T17:00:00.000Z", "headline" : "What Does A Blower Door Test Do?", "mainEntityOfPage" : { "@id" : "https://scsfoam.com/blog/what-does-a-blower-door-test-do", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://scsfoam.com/hubfs/branding/SCS-Updated-Logo_Horizontal-2048x397.png" }, "name" : "South Central Services" } } ```