If the HHV is known as part of a general energy management system, but not sampled on a routine basis, may Tier 1be used?
If the HHV is not sampled at the minimum frequency required for Tier 2, as part of your routine operations, Tier 1 may be used if your units are ≤ 250 mmBtu/hr and the fuel is listed in Table C-1. However, if HHV data are obtained at the minimum required frequency, then either Tier 2 must be used, or you may opt to use Tier 3 or 4. (See, §§98.33(b)(1), and 98.34(a)) If a combustion unit is greater than 250 mmBtu/hr, combusts a biomass fuel listed in Table C-1, and receives HHV data at the required frequency in §98.34(a), may Tier 1 be used per 40 CFR 98.33(b)(1)(iii)? No. For a unit of any size that combusts biomass, if HHV is sampled at the minimum frequency required for Tier 2 as part of routine operations, Tier 1 may not be used for determining the CO2 emissions from the combustion of biomass. Tier 2 must be used instead.
