ASHRAE-90.1-2022- - Page 102
Extracted Content
Table 6.5.6.1.2-1 Exhaust Air Energy Recovery Requirements for Ventilation Systems Operating Less than 8000 Hours per Year
| Climate Zone | % Outdoor Air at Full Design Airflow Rate | Col3 | Col4 | Col5 | Col6 | Col7 | Col8 | Col9 |
|---|---|---|---|---|---|---|---|---|
| Climate Zone | 10% and ** <20%** | 20% and ** <30%** | 30% and <40% | 40% and <50% | 50% and <60% | 60% and <70% | 70% and <80% | 80% |
| Climate Zone | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm |
| 3B, 3C, 4B, 4C, 5B | NR | NR | NR | NR | NR | NR | NR | NR |
| 0B, 1B, 2B,5C | NR | NR | NR | NR | 26,000 | 12,000 | 5000 | 4000 |
| 6B | 28,000 | 26,500 | 11,000 | 5500 | 4500 | 3500 | 2500 | 1500 |
| 0A, 1A, 2A, 3A, 4A, 5A, 6A | 26,000 | 16,000 | 5500 | 4500 | 3500 | 2000 | 1000 | 120 |
| 7,8 | 4500 | 4000 | 2500 | 1000 | 140 | 120 | 100 | 80 |
NR—Not required
Table 6.5.6.1.2-2 Exhaust Air Energy Recovery Requirements for Ventilation Systems Operating Greater than or Equal to 8000 Hours per Year
| Climate Zone | % Outdoor Air at Full Design Airflow Rate | Col3 | Col4 | Col5 | Col6 | Col7 | Col8 | Col9 |
|---|---|---|---|---|---|---|---|---|
| Climate Zone | 10% and <20% | 20% and <30% | 30% and <40% | 40% and <50% | 50% and <60% | 60% and <70% | 70% and < 80% | 80% |
| Climate Zone | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm | Design Supply Fan Airflow Rate, cfm |
| 3C | NR | NR | NR | NR | NR | NR | NR | NR |
| 0B, 1B, 2B, 3B, 4C, 5C | NR | 19,500 | 9000 | 5000 | 4000 | 3000 | 1500 | 120 |
| 0A, 1A, 2A, 3A, 4B, 5B | 2500 | 2000 | 1000 | 500 | 140 | 120 | 100 | 80 |
| 4A, 5A, 6A, 6B, 7, 8 | 200 | 130 | 100 | 80 | 70 | 60 | 50 | 40 |
NR—Not required
b. not allowed by ASHRAE/ASHE Standard 170 for use in energy recovery systems with leak age potential, or c. of Class 4 as defined in ASHRAE Standard 62.1. 7. Systems in Climate Zones 0 through 4 requiring dehumidification that employ series energy recovery and have a minimum SERR of 0.40. 8. Systems expected to operate less than 20 hours per week at the outdoor air percentage covered by Table 6.5.6.1.2-1. 9. Indoor pool dehumidifiers meeting Section 6.5.6.4.
6.5.6.1.2.1 Minimum Enthalpy Recovery Ratio. Energy recovery systems required by this section shall result in an enthalpy recovery ratio of at least 50% at the cooling design condition.
At the heating design condition, energy recovery performance shall be as follows:
a. Where active humidification is provided to spaces served by the system, energy recovery systems shall
result in an enthalpy recovery ratio of at least 50%. b. Where active humidification is not provided to spaces served by the system, energy recovery systems
shall result in a sensible energy recovery ratio of at least 50%.
The energy recovery system shall provide the required enthalpy recovery ratio or sensible energy recov- ery ratio at both heating and cooling design conditions unless one mode is not required for the climate zone by the exception to Section 6.5.6.1.2.
100 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)