LV-17-C051 -- Building Impacts of Code-Compliant Ventilation in Multi-Family Dwellings ✓ Most Recent

In recent years the majority of multi-family residential buildings have satisfied the ventilation requirements of the dwelling units via natural ventilationand have not provided an additional means of mechanical ventilation. Changes to ASHRAE Standard 62.1, Standard 62.2, and the adoption of thosechanges into local codes require multi-family dwelling units to be mechanically ventilated. This paper evaluates systems and equipment available to meetthe code mandated mechanical ventilation requirements and discusses the impacts of the selection on the building. Areas of impact evaluated are buildingaesthetics, capital cost, annual energy cost, utility billing structure, building space requirements, systems and equipment maintenance, and greenconstruction rating impact. When appropriate, the impact of building size is included in the evaluation. Not surprisingly, final mechanical ventilationsystem selection is a process of evaluating tradeoffs. For instance, distributed ventilation systems may not require shaft space in the building core butwould require louvers in the building facade. Providing energy recovery for the ventilation and exhaust systems reduces annual energy cost but increasesbuilding capital cost. As a result, a single recommendation cannot be provided as every building is not only physically different but the owner'srequirements, the funding structure, and impacts of a green rating system may change the appropriate system selection. Two buildings that would appearto have identical constraints after the fact may have been driven by two very different sets of owner requirements during design and construction and as aresult use very different approaches to provide mechanical ventilation to the dwelling units.