R403.6.2 Balanced Ventilation and HRV/ERV Systems (Mandatory)
In new buildings, every dwelling unit shall be served by a heat recovery ventilator (HRV) or energy recovery ventilator (ERV) installed per manufacturer's instructions. The HRV/ERV must be listed and sized adequately for the specific application, which will include the building's conditioned area, and number of occupants.
Exception: A balanced ventilation system designed and installed according to the requirements of Sections R403.6.2.1 through R403.6.2.3, using the return side of the building's heating and/or cooling system air handler to supply outdoor air, shall be permitted to comply with this section. When the outdoor air supply is ducted to the heating and/or cooling system air handler, the mixed air temperature shall not be less than that permitted by the heating equipment manufacturer's installation instructions. Heating and/or cooling system air handlers used to distribute outdoor air shall be fieldverified to not exceed an efficacy of 45 W/CFM if using furnaces for heating and 58 W/CFM if using other forms of heating. In the balanced system design, an equivalent exhaust air flow rate shall be provided simultaneously by one or more exhaust fans, located remotely from the source of supply air. The balanced system's exhaust and supply fans shall be interlocked for operation, sized to provide equivalent air flow at a rate greater than or equal to that determined by Table R403.6.2(1) and shall have their fan capacities adjusted for intermittent run time per Table R403.6.2(2). Continuous operation of the balanced ventilation system shall not be permitted.
|DWELLING UNIT |
|NUMBER OF BEDROOMS|
|0 — 1||2 — 3||4 — 5||6 — 7||> 7|
|Airflow in CFM|
|1,501 — 3,000||45||60||75||90||105|
|3,001 — 4,500||60||75||90||105||120|
|4,501 — 6,000||75||90||105||120||135|
|6,001 — 7,500||90||105||120||135||150|
For SI: 1 square foot = 0.0929 m2, 1 cubic foot per minute = 0.0004719 m3/s.