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FAQs on AHRI Standard 1330

Radiant Efficiency data has been a missing value in the proper measurement of gas-fired infrared heaters.
For far too long the certification and performance values of infrared heaters have been measured by
their Thermal Efficiency, a value once derived from the Boiler Industry. With the leadership of the Air
Conditioning, Heating & Refrigeration Institute (AHRI), and lessons learned from our European counterparts,
the CAN/ANSI/AHRI Radiant Efficiency Standard 1330 was finally published in early 2015.
As Standard 1330 is further refined and adapted, it is important that its related key terms, objectives and
impact be understood. This pamphlet provides a brief introduction to this topic and addresses Frequently
Asked Questions on Standard 1330.


Is AHRI Standard 1330 mandatory?
• There are no mandatory Standard 1330 certification requirements. Reporting is voluntary in North

Does AHRI Standard 1330 impact other certifications?
• No. Product testing, for certification purposes, will continue to measure Thermal Efficiency only, as per
the ANSI Standards. It should also be noted that a product claiming to be “Certified To” does not mean
that it is endorsed by any regulatory agency. The AHRI goal for Standard 1330 is a “Certified By” marking,
but this is not likely until 2019 or beyond. Be careful with misleading words and claims.

How will heaters be tested to AHRI Standard 1330?
• It is important to note that protocol and methodology for testing to Standard 1330 is still under
development by AHRI and no AHRI sanctioned testing facilities presently exist. Radiant efficiency data,
presently in circulation, is derived from a multitude of 3rd party test facilities. New testing guidance and
a revised Standard 1330 due for release in early 2018 and approved testing devices will soon follow.
• Pending edits of AHRI Standard 1330 (2018) call for a no greater than 5% testing discrepancy between
advertised and actual value and will require a sample model group to be tested 5 times to determine an
average value.

What does the term, Infrared Factor, mean?
• AHRI Standard 1330 referred to an Infrared Factor (IF). These Infrared Factors are found in various medias
throughout our Industry. Scaled 7 – 15, the Infrared Factor value is simply a number assigned to a Gross
Radiant Coefficient (GRC). The GRC is a percentage value of radiant energy tested in accordance with AHRI
Standard 1330.
NOTE: There is presently a proposal to abolish the Infrared Factor and simply test to and present the
Gross Radiant Coefficient performance values as a percentage of radiant output.

What are the minimum data requirements for published ratings?
• If a heater claims “Rated in accordance with AHRI Standard 1330”, it must include with this claim the
following data as described in AHRI Standard 1330, Section 7:
i. Model Number

ii. Heat Input

iii. Length of Heat Exchanger

iv. Infrared Factor v. Minimum Angle

Can a component (or Series) of a heater obtain an Infrared Factor or GRC Value?
• No. Only a heater meeting the criteria (i-v) defined above may claim rating to the AHRI Standard 1330.
This is important to note as claims without the minimum data requirements for published ratings
are false. It should also be noted that a series of heaters may not be valued in accordance with AHRI
Standard 1330, as this is reserved for only a specific heater.

What is the Formula for Radiant Efficiency?
• Well, it’s complicated AND its result varies greatly as present reports have testing discrepancies as high
as 10% between different labs and devices. Available online or upon request, the math and science
behind AHRI Standard 1330 is all public information. The fundamentals of the Stefan-Boltzmann Law still
apply. Essentially meaning that radiant output is a function of the area of emitter, the temperature of the
emitter and emitter emissivity

Learn more about efficiencies by visiting Detroit Radiant Products YouTube Channel at Efficiencies Understood (Video #6).