SMACNA IAQ Guidelines for Occupied Buildings under Construction recommends protecting HVAC system during construction. Ideally you would like to not run permanent installed system during construction. If possible, try to use a temporary system. If you have to use the system, the return air has to be protected with a MERV 8 filter to avoid any particulates and pollutants entering the duct system from the construction interiors. The supply air side also has to be protected, too. If you can’t install the filters then meet other requirements of HVAC protection. The ducts have to be cleaned and started up before occupancy to remove any leftover debris. You may find it helpful to provide a descriptive narrative of the project approach taken to comply with SMACNA guidelines and protect the ductwork in absence of MERV 8 filters. Refer to the referenced SMACNA guidelines http://www.smacna.org/bookstore/index.cfm?fuseaction=search_results&keyword=Accepted%20Industry%20Practice%20for%20Industrial%20Duct%20Construction,%202nd%20Edition,
Shillpa
Please get me up to date on this issue of using this variable refrigerant system units and filters. They are not ducted systems. They are dedicated small units that serve a zone. You can get a DOAS system that will have a filter in it but not likely a MERV 8. The small zone units have a tiny filter that is not MERV rated. What is the approach or CIR that we can find to deal with this? Smacna does not address this and no duct cleaning is needed during commissioning or constructon.