Evaluation of distributed environmental control systems for improving IAQ and reducing energy consumption in office buildings

Abstract

Conventional heating, ventilation, and air conditioning (HVAC) systems are incapable of providing control over individual environments or adjusting fresh air supply based on the dynamic occupancy of individual rooms in an office building. This paper introduces the concept of distributed environmental control systems (DECS) and shows that improvement in indoor air quality (IAQ) and energy efficiency can be achieved by providing required amounts of fresh air directly to the individual office spaces through distributed demand controlled ventilation (DDCV). In DDCV, fresh air is provided to each micro-environment (room or cubicle) based on input from distributed sensors (CO2, VOC, occupancy, etc.) or intelligent scheduling techniques to provide acceptable IAQ for each occupant, rather than for groups or populations of occupants. In order to study DECS, a numerical model was developed that incorporates some of the best available models for studying building energy consumption, indoor air flow, contaminant transport and HVAC system performance.The developed model was applied to a DECS in a model office building equipped with a DDCV system. By implementing DECS/DDCV and intelligent scheduling techniques it is possible to achieve an improvement in IAQ along with a reduction in annual energy consumption compared to conventional ventilation systems. Keywordsfast executing simulations, ventilation, distributed control systems, indoor air quality, office buildings Article History

Numerical Study on Effects of Air Return Height on Performance of an Underfloor Air Distribution System for Heating and Cooling

“…The dimensions of the full-scale computation domain were 6.0 m ×3.0 m × 2.6 m. Only half of the model in the X axis direction was investigated for cost-efficiency due to the symmetry of the air flow field ( Figure 2). The heating box (0.5 m × 0.4 m × 0.45 m) that was located 0.8 m above the floor represented the internal heat sources, including one occupant and two electrical appliances with total 440 W heat output [18]. The heating box that was used as human representatives released CO 2 .…”

Multi-zone simulation of outdoor particle penetration and transport in a multi-story building

“…The program has been widely used in research focusing on various contaminant transport issues. Recently, several researchers (Lai 2004;Sohn et al 2007;Demetriou and Khalifa 2009;Liu and Zhai 2009;Lim et al 2011;Miller 2011;Dols et al 2016) used CONTAMW to analyze aerosol transport issues, including not only airborne contaminants but also infectious bio-aerosols such as Severe Acute Respiratory Syndrome (SARS) and Influenza A (H1N1). Detailed governing equations for CONTAMW can be found in (Walton 1989) and (Walton and Dols 2005).…”

A multi-physical simulation on the IAQ in a movie theatre equipped by different ventilating systems

“…Recovery grids are located at the floor level. The PAD system (Arens et al 1998;Faulkner 2004;Demetriou et al 2009) supplies fresh air directly to the breathing area of a person. As it is applied in some movie theatres, diffusers are located on the chair back-side in order to supply fresh air to the person seated on the rear row (Niu et al 2007).…”