Image of man using tester device.
Image of blower door
Image of blower door

An airtight envelope has many key benefits including better comfort, lower energy use, cleaner indoor air, and better humidity control. Not only does this allow the house to perform better, it also makes it last longer. To ensure the home will be properly sealed, builders are now using the blower door test as a method of quality control throughout the build. A blower door consists of a calibrated fan, door panel, and a high-resolution manometer to bring the whole house to a desired test pressure. Houses are typically tested to 50 Pa of pressure. This can be positive or negative depending on which way the fan is facing. Most testers choose to test to -50 Pa to keep dampers from blowing open on bath and kitchen exhaust fans.

For new builds, multiple tests can be conducted from the framing stage to final. This helps ensure the air barrier remains intact as various trades make holes in the envelope and seal behind themselves. It is much easier and cost effective to repair the air barrier by sealing gaps, cracks, and other penetrations at earlier stages of the project instead of waiting until the end.

Keeping track of blower door test results is critical to maintaining the air tightness throughout the project. Once the house reaches the desired level of tightness, the goal is to maintain that blower door test result as the project continues. A process that automatically saves and organizes test results makes this easy. Back in 2013, Retrotec invented the first wireless touchscreen manometer for airtightness testing and named it the DM32. A few years later, they developed rCloud to work with it. rCloud is an app for smartphones and tablets that allows testers to run air tightness tests from their wireless device. Testers simply follow the prompts to conduct a test. This also helps prevent testers from forgetting certain parts of the process, such as the baseline reading. Once the test is complete, rCloud automatically generates a report that is saved to the cloud. All aspects of the test including the outdoor weather conditions and baseline readings are logged and saved. Multiple tests can be saved under one address so they can easily be referenced later.

Below are two reports from the same house. The first report is the first test at the framing stage. The second one is the next test after the envelope was sealed more once leaks were located. The goal was to get the house under 1 ACH50. We can see this was achieved when it was tested the second time. In this scenario, the builder would want to test a couple of more times to make sure they are still under 1 ACH50 as the build continues. A good time to test is after all mechanical, electrical, and plumbing penetrations are made and once again at the final stage of construction.

Image of rCloud on DM32X manometer

Both tests were conducted using rCloud on Retrotec’s new DM32X manometer, which is built on an Android platform. This allows Retrotec to place apps straight onto the manometer without any need to connect a phone or tablet. This frees up wireless devices to be used for other tasks. rCloud tests conducted on the DM32X can be run offline, saved locally on the manometer, and uploaded to the cloud later when there is an available Wi-Fi connection. This makes testing faster, prevents connectivity issues, and saves all tests in one place.

From laser distance measurers to temperature and humidity monitors, there is a wide variety of wireless tools to help us record and manage data in the world of home building. With the ability to automatically test, log, and save airtightness results, the blower door is no exception. Learn more at