Liquid to Liquid Brazed & Fusion Bonded Plate Heat Exchangers (LLBF)


Operations Manuals

Related Standard(s) and Documents

Additional Resources

Complete this form for each LLBF specification sheet verification request and submit by also completing this online form. A copy of the output sheet from the manufacturer’s Selection Rating Software must be submitted in conjunction with this form. All fields must be completed prior to submission. AHRI does not verify the mechanical attributes of a specification sheet; only the thermal performance is verified. Thermal performance includes Inlet Temperatures, Outlet Temperatures, Flow Rates, Pressure Drops, Heat Load, Heat Transfer Area, Density, Specific Heat Capacity, Thermal Conductivity, Viscosity, Heat Transfer Coefficient, L.M.T.D., and Channel Arrangements.

Please allow ten (10) business days for AHRI to conduct verification and respond to your request.

Program Scope

This program applies to Production Models of Brazed & Fusion Bonded Plate-Type Heat Exchangers, that utilize water on one or both circuits for HVAC applications only.

Program Scope Exclusions

This certification program excludes all of the following:

  • Heat exchangers used for phase-change heat transfer;
  • Heat exchangers used for non-liquid heat transfer;
  • Heat exchangers used for food-based processes;
  • Heat exchangers with a capacity greater than 16,000,000 Btu/h; and
  • Heat exchangers with a flow rate greater than 1,200 gpm.

HVAC Applications

The purpose of a heat exchanger in a HVAC-system is to directly or indirectly serve either of the heating, cooling or tap water system in any kind of building. Examples of these applications are:


  • Pressure interceptor
  • System isolator between cooling tower and chiller/dry cooler
  • Heat exchanger serving in the ice/chilled water storage system
  • Swimming pool cooler
  • Tap water cooler


  • Pressure interceptor
  • System isolator between boiler or heat pump, etc. and secondary heating system for space heating
  • Swimming pool heater
  • Tap water heater

District Energy (district cooling/district heating)

  • Heat exchanger in energy transfer station
  • Heat exchanger in free cooling application using a free cooling sink such as river water, lake water etc. to cool the district cooling water
  • Heat exchanger in free heating application using a hot stream from any source to heat district heating water

Certified Ratings

  • Total Heat Transfer Rate, Btu/h [W]
  • Hot Stream Pressure Drop, psig [kPa]
  • Cold Stream Pressure Drop, psig [kPa]

The rules and procedures for obtaining and maintaining certification are detailed in the Resources section above. The specific Standard listed above details the technical requirements for rating and publishing your product performance, the AHRI General Operations Manual (OM) details the program operational rules that are generic to all of AHRI’s certification programs and lastly, the Product-specific Operations Manual provides the operational rules that are specific to this program along with the required documents and fees. Please ensure that you are familiar with the latest rules and procedures for this program.