Gunnar Alquist
07-16-2008, 03:01 PM
I recently inspected a small office building and noted that the HVA/C blowers were not operating continuously. My understanding is that continuous blower operation is required to provide fresh air from the exterior when the building is occupied. None of the windows open.
From the International Mechanical Code:
401.3 When required. Ventilation shall be provided during the periods that the room or space is occupied.
403.3 Ventilation rate. Ventilation systems shall be designed to have the capacity to supply the minimum outdoor airflow rate determined in accordance with Table 403.3 based on the occupant load or other parameter as stated therein. The occupant load utilized for design of the ventilation system shall not be less than the number determined from the estimated maximum occupant load rate indicated in Table 403.3. Ventilation rates for occupancies not represented in Table 403.3 shall be determined by an approved engineering analysis. The ventilation system shall be designed to supply the required rate of ventilation air continuously during the period the building is occupied, except as otherwise stated in other provisions of the code.
My questions are:
1) Do I have this right? Is continuous mechanical ventilation required?
2) Is there some exception such as a small office occupancy?
3) Am I using the correct code section?
Thank you so much for your time and effort :cool:
From the International Mechanical Code:
401.3 When required. Ventilation shall be provided during the periods that the room or space is occupied.
403.3 Ventilation rate. Ventilation systems shall be designed to have the capacity to supply the minimum outdoor airflow rate determined in accordance with Table 403.3 based on the occupant load or other parameter as stated therein. The occupant load utilized for design of the ventilation system shall not be less than the number determined from the estimated maximum occupant load rate indicated in Table 403.3. Ventilation rates for occupancies not represented in Table 403.3 shall be determined by an approved engineering analysis. The ventilation system shall be designed to supply the required rate of ventilation air continuously during the period the building is occupied, except as otherwise stated in other provisions of the code.
My questions are:
1) Do I have this right? Is continuous mechanical ventilation required?
2) Is there some exception such as a small office occupancy?
3) Am I using the correct code section?
Thank you so much for your time and effort :cool: