N.H. Rev. Stat. Ann. § 339-G:6

The manufacturers of products listed in RSA 339-G:2, I shall test samples of their products in accordance with the test procedures established in this chapter or those specified in the state building code as defined in RSA 155-A. The department shall adopt by rule test procedures for determining the energy efficiency of the products listed in RSA 339-G:2, I if such procedures are not provided for in RSA 339-G:3 or in the state building code. The department shall adopt United States Department of Energy approved test methods, or in the absence of such test methods, other appropriate nationally-recognized test methods. The department may adopt updated test methods when new versions of test procedures become available.