Liquid to Liquid Heat Exchangers (LLHE)


Program-specific Forms

Operations Manuals

Related Standard(s) and Documents

Additional Resources

Complete this form for each LLHE 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 gasketed plate-type heat exchangers, that utilize any of the following fluids on one or both circuits, for HVAC applications only.

  • Water;
  • Seawater;
  • Ethylene Glycol (10%-50% concentration);
  • Propylene Glycol (10%-50% concentration)

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 240,000,000 Btu/h;
  • Heat exchangers with a flow rate greater than 20,000 gpm.
  • Heat exchangers with pass arrangements above 3 passes per side; or
  • Heat exchangers with unequal number of passes per side.

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.