In the event a building is deemed less than an ideal candidate for retrofitting basic air cleaning systems, the limitations will be identified and proposals made for modifying building ventilation systems or operating conditions to enable successful implementation. In some cases, building fans and motors may lack the capacity to handle the pressure losses associated with new filters. Losses in total supply air volume and/or increases in power consumption may occur in some systems. Every effort will be made to maintain building system operating conditions under any retrofit of immune building technologies. In some cases, existing operating conditions may have deviated from original building design requirements. A review of such conditions will be performed in conjunction with building owners to determine the best course of action.