The Air-conditioning and Refrigeration Institute (ARI) is the HVAC industry's principle organization, representing 90 percent of the manufacturers of air-conditioning, refrigeration and heating products.

Its activities include:

  • Establishing standards for testing and rating products,
  • Sponsoring and administering product certification programs,
  • Testing products to verify certified performance ratings,
  • Publishing certified product directories, and
  • Designing and administering consumer education programs.

The applicable standards for rating and testing geothermal heat pump systems are:

  • ARI Standard 325 Ground Water-source Heat Pumps,
  • ARI Standard 330 Ground Source Closed-Loop Heat Pumps, and
  • ARI Standard 870 Direct Geoexchange Heat Pumps.

There ARI standards maybe viewed and downloaded using their website ARI has adopted ARI/ISO Standard-13256-1 as the basis for its certification programs in lieu of standards 325 and 330.

Each of these standards are backed by an on-going certification program, which includes random tests at an independent laboratory under contract to ARI. Participating manufacturers certify that their ratings conform to the applicable standard and publish these as part of their product catalogs. They indicate their participation by displaying the ARI seal on all units of certified models, all specification sheets, and other literature mentioning ratings. In order to be certified, models must pass at least three classes of performance tests:

  1. A Maximum Operating Conditions Test, both on heating and cooling,
  2. Low temperature Start and Operate Tests,
  3. An Insulation Efficiency Test conducted continuously with cooling tests to ensure that no condensed water will drip, run, or blow off the unit casing.

Periodically, ARI updates the Directory of Certified Applied Air-conditioning Products, which includes geothermal heat pumps. All ARI Directories (applied and unitary) are web accessible at via PrimeNet. Directories are available after ARI receives a written request from an individual or company in air-conditioning or allied industries.