That is your OAT intake, your economizer and the dampers are set to maintain MIN of proper fresh air intake per code.. I assume this is a new install the inspector is checking only what is required...Like you said some years ago all units over 5tons need to have auto dampers no fixed. I will assume you will have all this balanced. Once everyone is gone and if you have a control system you should be able to set the min to what you want...In deep summer, high temps-high Humidity i shut mine to 0%. and depending on the size you may need spill dampers to maintain static. This is basic HVAC
Originally Posted by alex1960
Just a note about CO2...so many people worry about indoor CO2 but very few have sensors outside... I have seen where the CO levels outside are worse than inside and the dampers still open because many forget to measure outdoor and indoor CO2. If your going to install CO2 sensors do it right.
I've seen some codes that wanted a motorized damper for smoke/fire shut down instead a RTU mounted chimney with barometric relief and fixed % intake.
Steam that was the "standard" or "rule of thumb" before we had 62.1. and the code requirement for ventilation. There is no "10%" standard anymore. The IMC 2006 calls for different ventilation rates based on the type of building and rooms such as restrooms, classrooms, office areas, etc.
Originally Posted by steam638
Typically you are talking about 15% or more in most cases. LEED points for air quality requires a lot more. The 2012 code does require motorized dampers for outside air. We don't have that code yet in GA but will have it Jan 1, 2014. Don't know to much about that yet other that in some cases you are allowed to have less OA than in the IMC 2006. Thank you very much