Henchalwoog
Member
- Joined
- Nov 6, 2009
- Messages
- 10
I am struggling with the ERV requirements listed in the IECC table C403.2.6 (2012) - based on our climate (5A) it would appear to prohibit 100% outside air systems such as an exhaust fan and louver setup...however it WOULD NOT prohibit a fan system that runs at 50% of the required air flow and under 3500 cfm...so I take that as meaning if I have to exhaust 2000 cfm I cannot do it with 1 2000 cfm fan (100% of design airflow requirement) but if I split it into 2 fans (1000 cfm each) and louvers I can do it? That does not make sense of course but the exceptions to this section also indicate an ERV is required if there is a single source exhaust that is less than 75% of the design outdoor airflow rate which would support that idea.