“Closed loop” daylighting controls only control one set of fixtures. With “open loop” controls, multiple zones can be controlled from one sensor and each zone can be calibrated independently to the daylight available in that zone.
Class-A, commercial office buildings are most likely to have mechanical systems that are compatible with MERV 13 filtration. These buildings commonly supply outside air through air handling or rooftop units and do not experience the same compatibility issues of smaller systems.
Any type of project can have a compatibility issue, but hospitality and multifamily projects are particularly challenging because they are often served by small, packaged systems.
To minimize problems with pressure drop, look for filters that have a low initial resistance to airflow. Generally, the lower the initial resistance to airflow, the lower the energy use. This information can be found on product cut sheets.
Some buildings have incompatible mechanical systems. This stems from both a lack of available products that physically fit in filter housings and increased resistance to airflow, known as “pressure drop.” A
If you are developing an energy model for compliance with EAc1.3: Optimize Energy Performance—HVAC, it can help with the lighting system design and to optimize integration with other building systems.
Task lights can be exempt from the calculations if they are furniture-mounted with independent controls (automatic shut-off by timer or occupancy-sensor, see ASHRAE 90.1-2007, 9.2.2.3,p). Plug-in task lights can also be exempt if they are not part of the overall lighting strategy, meaning they are not specified in the design documents. However, if they are exempted from the calculation, they cannot be counted for EQc6.1: Controllability of Systems—Lighting.
