How Does Your Blower Door and Duct Tester Manufacturer

Manage for Accuracy and Repeatability in Their Lab?

Building and HVAC performance testers around the world rely on calibrated fans and pressure gauges to determine the construction quality of building envelopes, duct systems, and other building components. These tools include blower doors and duct testers which have been used for decades to measure the air tightness of certain assemblies. For these tools to become and remain accurate, they must be calibrated by the manufacturer once they are built and re-calibrated after a certain period specified by the manufacture. With Retrotec tools, this is every five years for gauges and fans.

Since these tools are often used to meet quality assurance standards for buildings and HVAC systems, have you ever wondered what quality assurance processes the tool manufacturer goes through? How do you know if the manufacturer’s lab is competent enough to successfully perform such a delicate and precise calibration service? This is where a laboratory accreditation becomes valuable to the end user. In an article by the International Laboratory Accreditation Cooperation (ILAC), laboratory accreditation is defined as:

“…a means of determining the technical competence of laboratories to perform specific types of testing, measurement and calibration. It also provides formal recognition to competent laboratories, thus providing a ready means for customers to identify and select reliable testing, measurement and calibration services able to meet their needs.”

For building and HVAC diagnostic tools, ISO/IEC 17025 is the laboratory accreditation for calibration that is globally recognized. Retrotec is the only blower door manufacturer in the United States to have this accreditation. This year, Retrotec took their accreditation to the next level by completing all requirements to meet the 2017 version of the ISO/IEC 17025 accreditation. This is the latest and most difficult version to achieve and maintain. Retrotec was previously meeting the 2005 version and passed the requirements for the latest version on the first attempt. Not only does this certification help provide Retrotec’s customers with the most accurate and reliable tools on the market, it is a standard that is recognized worldwide.

The ISO/IEC 17025 general requirements for the competence of testing and calibration laboratories is the main ISO standard used by testing and calibration laboratories. In most countries, ISO/IEC 17025 is the standard for which most labs must hold accreditation in 

order to be deemed technically competent. In addition to the ISO/IEC 17025 accreditation, Retrotec is also an ILAC member which means it has permission to display the ILAC-MRA mark on all calibration reports. In order to do this, Retrotec must pass their accreditation audit on an annual basis for their lab, procedures, and staff.

In addition to the ISO accreditation and ILAC mark, the auditor also confirms whether Retrotec is following Nation Institute of Standards and Technology (NIST) standards for their reference devices and flow chambers. This is an additional voluntary standard that Retrotec follows for optimum quality assurance.

Retrotec’s Calibration Process

A new batch of DM-32 gauges get their first calibration before being shipped off to customers

All of Retrotec’s blower doors, DucTesters and pressure/flow gauges are built by hand in Everson, WA. Once a fan or gauge completes its journey down the assembly line, it is calibrated in the ISO/IEC 17025-2017 accredited lab before it is shipped out to its destination. The calibration results are published to Retrotec’s cloud-based portal which provides end users and authorities the ability to lookup the calibration certificate online. This is done by scanning a QR code on the device with a smartphone or directly entering the serial number in the portal. The ability to simply enter the serial number of your fan into our testing software (rCloud and FanTestic) automatically enters the coefficients for best fit for your specific fan which ensures you get the most accurate results possible.

As you can see, there is a lot of hard work that happens behind the scenes at Retrotec to make sure you get the best possible product to take measurements in the field. If you are investing in new diagnostic tools to improve your business, always take the time to see which standards manufactures hold themselves to when making and designing your equipment.