In this work, a novel approach for the automated fault detection and diagnostics (AFDD) of building HVAC operation is introduced utilizing properties of the Koopman operator to extend the capabilities of rules-based FDD approaches. The Koopman operator is an infinite-dimensional, linear operator that captures nonlinear, finite dimensional dynamics. These mathematical aspects translate into algorithms which can effectively evaluate the magnitude and coincidence of data. Using properties of the operator, building management system (BMS) trend data can be decomposed into components which allow the capture of device-to-device interactions as well as device behavior at varying time-scales.

Natural ventilation is one of the most important green building features. Although the intention is often to reduce energy consumption, natural ventilation strategies may deteriorate indoor air quality (IAQ) when in close proximity to major roadways. This study employs a CFD-based air quality model to quantify the impact of traffic-related air pollution on the IAQ of a naturally ventilated building in a near-road environment. Our study found that the building envelope restricts dispersion and dilution of particulate matter (PM).

As cars are parked within an underground parking structure, CO and other exhaust fumes are emitted into the atmosphere. There is a need for an efficient ventilation system that can remove these toxins, circulate fresh air into the garage, and assist fire fighters in the case of a fire emergency. There are two options for this task: ducted or ductless ventilation. Ducted ventilation is heavily used in the US and other global markets. While this has been the standard for many years, innovations in the field of ventilation have shifted the conventional ventilation system towards ductless designs.

ASHRAE Standard 62.1-2013 provides two alternative procedures for selecting the minimum ventilation rate for commercial buildings: the prescriptive Ventilation Rate Procedure (VRP); and the rarely used performance-based Indoor Air Quality Procedure (IAQP). The IAQP allows lower ventilation rates than the VRP and, at a minimum, maintains the same indoor air quality, providing additional contaminant reduction strategies are applied. This paper provides examples, benefits and lessons learned from applying IAQP in various commercial buildings located in a variety of climates.

Flexible duct air distribution systems are used in a large percentage of residential and small commercial buildings in the United States. Very little empirical or predictive data is available to help provide the HVAC design engineers with reliable information. The aim of this research is to measure experimentally using the guidelines of ANSI/ASHRAE Standard 120-2008 the friction loss of the air flow inside a realistic layout out flexible duct used for residential/small commercial buildings.