Where the supply airflow rate of a fan system exceeds the values specified in Table C403.2.6, the system shall include an energy recovery system. The energy recovery system shall have the capability to provide a change in the enthalpy of the outdoor air supply of not less than 50 percent of the difference between the outdoor air and return air enthalpies, at design conditions. Where an air economizer is required, the energy recovery system shall include a bypass or controls which permit operation of the economizer as required by Section C403.4
1. Where energy recovery systems are prohibited by the Florida Building Code, Mechanical.
2. Laboratory fume hood systems that include at least one of the following features:
2.1. Variable-air-volume hood exhaust and room supply systems capable of reducing exhaust and makeup air volume to 50 percent or less of design values.
2.2. Direct makeup (auxiliary) air supply equal to at least 75 percent of the exhaust rate, heated no warmer than 2°F (1.1°C) above room setpoint, cooled to no cooler than 3°F (1.7°C) below room setpoint, no humidification added, and no simultaneous heating and cooling used for dehumidification control.
3. Systems serving spaces that are heated to less than 60°F (15.5°C) and are not cooled.
4. Where more than 60 percent of the outdoor heating energy is provided from site-recovered or site solar energy.
5. Heating energy recovery in Climate Zones 1 and 2.
6. Cooling energy recovery in Climate Zones 3C, 4C, 5B, 5C, 6B, 7 and 8.
7. Systems requiring dehumidification that employ energy recovery in series with the cooling coil.
8. Where the largest source of air exhausted at a single location at the building exterior is less than 75 percent of the design outdoor air flow rate.
9. Systems expected to operate less than 20 hours per week at the outdoor air percentage covered by Table C403.2.6.
ENERGY RECOVERY REQUIREMENT
|CLIMATE ZONE||PERCENT (%) OUTDOOR AIR AT FULL DESIGN AIRFLOW RATE|
|≥ 30% and < 40%||≥ 40% and < 50%||≥ 50% and < 60%||≥ 60% and < 70%||≥ 70% and < 80%||≥ 80%|
|DESIGN SUPPLY FAN AIRFLOW RATE (cfm)|
|3B, 3C, 4B, 4C, 5B||NR||NR||NR||NR||≥ 5000||≥ 5000|
|1B, 2B, 5C||NR||NR||≥ 26000||≥ 12000||≥ 5000||≥ 4000|
|6B||≥ 11000||≥ 5500||≥ 4500||≥ 3500||≥ 2500||≥ 1500|
|1A, 2A, 3A, 4A, 5A, 6A||≥ 5500||≥ 4500||≥ 3500||≥ 2000||≥ 1000||> 0|
|7, 8||≥ 2500||≥ 1000||> 0||> 0||> 0||> 0|